XXVI International Workshop on Deep Inelastic Scattering and Related Subjects

16 Apr 2018, 09:00 → 20 Apr 2018, 18:00 Asia/Tokyo

Kobe University Convention Centre / Kobe International Conference Center

Yuji Yamazaki (Kobe University (JP))

Welcome to DIS2018. This is the 26th in an annual series of International Workshops covering an eclectic mixture of material related to Quantum Chromodynamics and DIS as well as a general survey of the hottest current topics in high energy physics. Much of the program is devoted to the most recent results from experiments at BNL, CERN, DESY, FNAL, JLab, and KEK. Relevant theoretical advances are also covered in detail.

On Tuesday 17 Apr from 16:30 (9:30 CET), there will be a special discussion session for a document for European Strategy Update. Vidyo connection is available (only for this session). See the link in the menu on the left.

For your info: there will be a satellite meeting "pre-DIS2018 EIC workshop" on Sunday 15 April from 9:00 at the same conference hall as our plenary sessions. There will be also registration open for those who paid already.

0416a1_coffee.pptx

0416p1_coffee.pptx

1030_A2_2.pdf

Bulletin_DIS2018_0327.pdf

Bulletin_DIS2018_0412.pdf

bus.pdf

ConfLocations_DIS2018.pdf

K_tour_information.pdf

LOCannounce-1904_no2.pdf

PINFO-01.pdf

Shuttle Timetable from Sannomiya to Itami Airport

Shuttle Timetable from Sannomiya to Kansai Airport

Monday 16 April

Plenary Session: Plenary-1

Convener: Hideto Enyo (RIKEN (JP))

1 Conference Opening

Speaker: Prof. Hiroshi Takeda (President, Kobe University)

2 Practical information on the workshop

Speaker: Yuji Yamazaki (Kobe University (JP))

0416a1_Welcome.pdf

3 New results on parton densities of nucleons and nuclei

Speaker: Stefan Schmitt (Deutsches Elektronen-Synchrotron (DE))

DIS2018_Stefan.pdf

4 New results on spin and 3D structure measurements

Speaker: Haiyan Gao (D)

DIS2018-HGao.pdf

10:40 Coffee break

Plenary Session: Plenary-2

Convener: Barbara Badelek (University of Warsaw (PL))

5 Studies on lepton-hadron interactions for precision neutrino physics

Speaker: Yoshinari Hayato (University of Tokyo)

20180415_Hayato_DIS2018.pdf

6 Progress in QCD studies for high-sensitivity EW, Higgs and BSM measurements

Speaker: Jan Kretzschmar (University of Liverpool (GB))

DIS18_Kretzschmar_EWHiggsSearch.pdf

7 Collider studies on jet and heavy flavour properties

Speaker: Dr Vieri Candelise (Universita e INFN Trieste (IT))

DIS2018_VieriCandelise.pdf

12:50 Conference photo

13:00 Lunch

Plenary Session: Plenary-3

Convener: Robert Samuel Thorne (University College London (UK))

8 Multi-leg hadronic final state calculation and simulation

Speaker: Rikkert Frederix (TUM)

frederix.pdf

9 Altarelli Prize celemony

Speaker: Elisabetta Gallo (DESY)

Presentation_award_2018.pdf

10 Altarelli Prize talk 1

Speaker: Dr Jun Gao (Jiao Tong University, Shanghai)

DIS-Altarelli-JunGao.pdf

11 Altarelli Prize talk 2

Speaker: Or Hen (Massachusetts Institute of Technology)

DIS2018_Hen.pdf

12 Recent results on forward physics

Speaker: Joakim Nystrand (University of Bergen (NO))

nystrandDIS2018.pdf

16:10 Coffee break

Plenary Session: Plenary-4

Convener: Halina Abramowicz (Tel Aviv University (IL))

13 Experimental studies on fragmentation and exotic hadrons

Speaker: Kenkichi Miyabayashi (Nara Women's University)

dis2018_miyabayashi.pdf

14 Hadron shape fluctuation and its relation to DIS

Speaker: Dr Heikki Mäntysaari (University of Jyväskylä)

dis18_mantysaari.pdf

15 Lattice QCD and Hadron Structure

Speaker: Yasumichi Aoki (N)

DIS2018_yaoki.pdf

Social Events: K Computer visit (limited to 70 people)

Social Events: Conference Reception

Convener: Junpei Maeda (Kobe University (JP))

Tuesday 17 April

WG1: Structure Functions and Parton Densities: Session 1

16 Determination of the strong coupling constant $\alpha_s(M_Z)$ in next-to-next-to-leading order QCD using H1 jet cross section measurements

The strong coupling constant $\alpha_s(m_Z)$ is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of $\alpha_s(m_Z)$ at the Z-boson mass m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be $\alpha_s(m_Z)=0.1157\,(20)_{exp}\,(29)_{th}$ . Complementary, $\alpha_s(m_Z)$ is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value $\alpha_s(m_Z)=0.1142\,(28)_{tot}$ obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

Eur.Phys.J.C77 (2017), 791 [arxiv:1709.07251]

Speaker: Radek Zlebcik (Deutsches Elektronen-Synchrotron (DE))

KobeAlphaS_Zlebcik.pdf

17 Determination of electroweak parameters using H1 inclusive DIS data

An improved determination of electroweak (EW) parameters using H1 inclusive neutral current and charged current DIS cross sections is presented. The analysis benefits from the usage of the previously published cross sections using longitudinally polarised lepton beams. The parameters are determined in a combined fit of EW parameters together with PDFs. The predictions include NNLO QCD corrections for the PDF and structure function calculations, and the corrections at the leptonic vertex are obtained in the on-shell scheme including the full set of 1-loop corrections. The analysis determines the weak neutral-current couplings of the light quarks and thus tests potential contributions beyond the SM. The mass of the W-boson is determined and a precision of 115 MeV is achieved.

Speaker: Zhiqing Philippe Zhang (LAL, Orsay (FR))

Zhang_DIS18.pdf

18 MC tuning using the HHT PDF set with the low-x higer-twist term.

In the HHT QCD fit the standard DGLAP evolution was augmented by including an additional low-x higher-twist term in the description of the longitudinal structure function, F$_\rm{L}$. This additional term significantly improves the description of the HERA reduced cross sections at low Bjorken-x and low four-momentum-transfer squared, Q$^2$. Since the HHT fit describes well data from the highest Q$^2$ down to Q$^2$ of a few GeV$^2$, it can be used in studies to tune MC samples using the LHC underlying event variables. Preliminary trsults of this tuning will be shown in this presentation.

Speaker: Katarzyna Wichmann (Deutsches Elektronen-Synchrotron (DE))

kwichmann-dis18-hhtMCtune.pdf

19 Jet Correlation Measurements at ATLAS and the determination of the strong coupling constant

The production of multi-jet final states at hadron colliders probes pQCD at several mass scales. The processes can also be used to probe the gluon density function of the proton. The ATLAS collaboration has used multi-jets events, recorded at a center of mass energy of 8 TeV, to measure the transverse energy-energy correlations, its asymmetry and the dijet azimuthal decorrelation. These measurements are particularly sensitive to the strong coupling constant with a reduced model dependency. The resulting value of $Äalpha_s$ and the corresponding tests of the renormalization group equation will be presents.

Speaker: Markus Wobisch (Louisiana Tech University (US))

20180410-DIS18-TEEC.pdf

20 TeV-PeV neutrino-nucleon cross section measurement with 5 years' IceCube data

IceCube is a 1 cubic kilometer size neutrino detector located at the South Pole. It is capable of detecting all-sky neutrinos of all flavors from GeV to EeV energies. After detector completion, it discovered and measured the flux of extraterrestrial neutrinos in the TeV - PeV energy range, alongside with flux of neutrinos of known atmospheric origin. In this talk we will present a novel analysis method and the preliminary result of the neutrino-nucleon Deep Inelastic Scattering (DIS) cross section measurement as a function of neutrino energy in the TeV – 10 PeV energy range utilizing neutrino absorption by the Earth.

We analyzed five years of data collected with complete IceCube detector from May 2011 to May 2016. This analysis focuses on electromagnetic and hadronic showers (cascades) mostly induced by electron and tau neutrinos. The applied event selection features high background rejection (<10% background contamination below 60TeV, background free above 60TeV) in rejecting atmospheric muons and high signal efficiency (~80%). The final neutrino sample consists of about 5600 events, with about 420 events above 10TeV reconstructed energy. An unfolding method was applied to enable the mapping from reconstructed cascade parameters such as neutrino energy and zenith to true neutrino variables. The analysis was performed assuming isotropic astrophysical neutrino flux, in in seven energy bins, and in two zenith bins (“down-going” from the south-hemisphere and “up-going” from the north-hemisphere). The ratio of down-going events and up-going events (absorbed by the Earth at large energies) is sensitive to the neutrino-nucleon DIS cross section and is insensitive to the dominant neutrino flux uncertainties.

The neutrino-nucleon DIS cross section preliminary result will be compared with the Standard Model theoretical calculation.

Speaker: Yiqian Xu (Stony Brook University)

xsec_DIS2018_yxu.pdf

WG2: Small-x and Diffraction: Session 1

21 Exclusive Photoproduction of $2\pi^+2\pi^-$ Final State at HERA

Exclusive production of four charged pions at the ep collider HERA is studied at small photon virtualities $Q^2<2$ GeV${}^2$. The data were taken with the H1 detector in the years 2006 and 2007 at a centre-of-mass energy of $\sqrt{s}=319$ GeV and correspond to an integrated luminosity of 7.6 pb$^{-1}$. The cross section of the reaction $\gamma p \to 2(\pi^+\pi^-)Y$ is determined in the phase space of $45\lt W_gp\lt 100$ GeV, $\vert t\vert\lt 1$ GeV${}^2$ and $M_Y\lt 1.6$ GeV. The $4\pi$ mass spectra indicate that the reaction proceeds predominatly via production and decay of $\rho^{\prime}(1450)$ and $\rho^{\prime\prime}(1700)$ resonances. Parameters of these resonances as well as production cross sections times branching ratio into four charged pions are estimated from the mass fit, which includes contributions from non-resonant $4\pi$ channel and interference terms.

Speaker: Stefan Schmitt (Deutsches Elektronen-Synchrotron (DE))

dis2018fourPi.pdf

22 Deep inelastic scattering in the dipole picture at next-to-leading order

We study quantitatively [1] the importance of the recently derived NLO corrections [2,3,4] to the DIS structure functions at small x in the dipole formalism. We show that these corrections can be significant and depend on the factorization scheme used to resum large logarithms of energy into renormalization group evolution with the BK equation. This feature is similar to what has recently been observed for single inclusive forward hadron production [5,6]. Using a factorization scheme consistent with the one recently proposed for the single inclusive cross section, we show that it is possible to obtain meaningful results for the DIS cross sections. We also discuss ongoing work to combine these NLO DIS structure functions in the improved factorization scheme with the resummed/NLO BK evolution equation in order to do consistent NLO accuracy comparisons with HERA data.

[1] B. Ducloué, H. Hänninen, T. Lappi, Y. Zhu, Phys.Rev. D96 (2017) no.9, 094017
[2] G. Beuf, Phys.Rev. D94 (2016) no.5, 054016
[3] G. Beuf, Phys.Rev. D96 (2017) no.7, 074033
[4] H. Hänninen, T. Lappi, R. Paatelainen, arXiv:1711.08207 [hep-ph]
[5] E. Iancu, A.H. Mueller, D.N. Triantafyllopoulos, JHEP 1612 (2016) 041
[6] B. Ducloué, T. Lappi, Y. Zhu, Phys.Rev. D95 (2017) no.11, 114007

Speaker: Henri Hänninen (University of Jyväskylä)

hanninen_DISXXVI_handout.pdf

hanninen_DISXXVI_presentation.pdf

23 Inclusive photon production to NLO at small x as a probe of gluon saturation

We report on a first NLO computation of inclusive photon production at small x in
e+A collisions. The computation is performed to next-to-leading-log x accuracy and resums all multiple scattering (higher twist) computations within the CGC effective theory. In the soft photon (Low) limit, we recover results the NLO results of Balitsky and Chirilli for inclusive DIS. We point to key technical improvements of our computation relative to the latter which opens the door to more efficient small x computations. We also discuss the relation of this work to analogous computations by us for p+A collisions.

Speaker: Dr Raju Venugopalan (BNL)

DIS2018_raju.pdf

24 Electron-photon deep inelastic scattering at small x in holographic QCD

A photon is a fundamental particle, instead of a nonperturbative composite like hadrons. However, an energetic photon can fluctuate into vector mesons in the kinematic region with a small Bjorken variable $x < 0.1$. Particularly at $x < 0.01$, the hadronic contribution to cross sections of the electron-photon deep inelastic scattering dominates, and a photon can be regarded as a hadron rather than a pointlike object. Therefore, effective models are needed for studies of the photon structure in this kinematic region. We present analysis on the photon structure functions at small $x$ in the framework of the holographic QCD, assuming dominance of the Pomeron exchange. The real photon structure functions are expressed as convolution of the Brower-Polchinski-Strassler-Tan (BPST) Pomeron exchange kernel and the known wave functions of the U(1) vector field in the five-dimensional AdS space, in which the adjustable parameters in the BPST kernel have been fixed in previous studies of the nucleon structure functions. The predicted photon structure functions, as confronted with experimental data, provide a clean test of the BPST kernel. The agreement between theoretical predictions and data is demonstrated, which supports applications of holographic QCD to hadronic processes in the nonperturbative region. Our calculations are also consistent with those derived from the parton distribution functions of the photon proposed by Gluck, Reya, and Schienbein, implying realization of the vector meson dominance in the present model setup. Our results presented in this talk will be tested at future linear colliders, e.g., the planned International Linear Collider.

Speaker: Akira Watanabe

DIS2018_Watanabe.pdf

25 NNLO QCD predictions for dijet production in diffractive DIS

Calculations for dijet production in diffractive deep-inelastic scattering (DIS) at next-to-next-to-leading order accuracy (NNLO) are presented. The calculations are based on the antenna subtraction formalism and the hard coefficients are convoluted with currently available PDFs for diffractive scattering (DPDFs).
The NNLO predictions are compared to a large number of available measurements and different observables. Detailed studies on the DPDF and scale dependencies are presented.

Speaker: Radek Zlebcik (Deutsches Elektronen-Synchrotron (DE))

dDISdijets_Zlebcik.pdf

WG3-WG5 Joint Session

26 Search for new physics in CP violation with beauty and charm decays at LHCb

Precision measurements of CP violating observables in the decays of b and c hadrons are powerful probes to search for physics beyond the Standard Model.
The most recent results on CP violation in the decay, mixing and interference of both b and c hadrons obtained by the LHCb Collaboration with Run I and years 2015-2016 of Run II are reviewed. In particular world best constraints and world first measurements are provided for CKM elements, unitarity angles and charm parameters.

Speaker: Cameron Dean (University of Glasgow (GB))

LHCb_CPV_DIS2018_C_Dean.pdf

27 B-flavour anomalies in b->sll and b->clnu transitions at LHCb

The concept of lepton universality, where the muon and tau particles are simply heavier copies of the electron, is a key prediction in the Standard Model (SM). In models beyond the SM, lepton universality can be naturally violated with new physics particles that couple preferentially to the second and third generation leptons. Over the last few years, several hints of lepton universality violation have been seen in both b->c and b->s semileptonic beauty decays. This presentation will review these anomalies and give an outlook for the near future.

Speaker: Olaf Steinkamp (Universitaet Zuerich (CH))

180417_DISANOM.pdf

28 Production and decay of HF in ATLAS

The angular analysis of the decay of Bd -> K* mu mu for a number of angular coefficients are measured as a function of the invariant mass squared of the di-muon system for data collected at 8 TeV. Comparison is made to theoretical predictions, including for the observable P’5, for which there has been recent tension between theory and experiment. In addition the study of kinematical correlations in B hadron pair production is also presented.

Speaker: Angel Fernando Campoverde Quezada (Universitaet Siegen (DE))

Production_and_Decay_of_Heavy_Flavor_in_ATLAS.pdf

29 Study of electroweak-penguin B decays and other rare B decays at Belle

Electroweak penguin B decays proceed through one loop diagrams at the lowest order. Since new particles beyond the Standard Model can enter in the loop, these processes are very sensitive to new physics. We report measurements of b → sl+l- decays at Belle. We also report other rare B decays sensitive to New Physics. The analyses are based on the full data set at Y(4S) and Y(5S) resonances at Belle.

Speakers: Luka Santelj (High Energy Accelerator Research Organization (KEK)), Luka Santelj (Jozef Stefan Institute)

dis2018_belle_Santelj.pdf

WG4: Hadronic and Electroweak Observables: Session 1

30 Measurement of the diboson production cross section at 8TeV and 13TeV and limits on anomalous triple gauge couplings with the ATLAS detector

Measurements of the cross sections of the production of pairs of electroweak gauge bosons at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration has performed detailed measurements of integrated and differential cross sections of the production of heavy di-boson pairs in fully-leptonic and semi-leptonic final states at centre-of-mass energies of 8 and 13 TeV. The results are compared to predictions at NLO (and NNLO) in pQCD and provide constraints on new physics, by setting limits on anomalous triple gauge couplings.

Speaker: Bing Zhou (University of Michigan (US))

dis2018-bz-v5.pdf

31 WW production at NNLO+PS

We present predictions for diboson production (with exact decays) that are next-to-next-to-leading order (NNLO) accurate and consistently matched to a parton shower (NNLOPS). The matching is achieved by upgrading the NLO WW+j calculation with MiNLO, in such a way that NLO accuracy is guaranteed for W+W- inclusive observables and by then performing a reweighting of the WWJ-MiNLO events, differential in the W+W- Born variables, to the NNLO results obtained with Matrix.

Speaker: Emanuele Re (CERN)

2018_04_17.pdf

32 Vector boson scattering, triple gauge-boson final states and limits on anomalous quartic gauge couplings with the ATLAS detector

Measurements of the cross sections of the production of three electroweak gauge bosons and of vector-boson scattering processes at the LHC constitute stringent tests of the electroweak sector of the Standard Model and provide a model-independent means to search for new physics at the TeV scale. The ATLAS collaboration searched for the production of three W bosons or of a W boson and a photon together with a Z or W boson at a center of mass energy of 8 TeV. ATLAS has also searched for the electroweak production of a heavy boson and a photon together with two jets. Evidence has been found for the exclusive production of W boson pairs. All results have been used to constrain anomalous quartic gauge couplings and have been compared to the latest theory predictions.

Speaker: Tatsumi Nitta (Waseda University (JP))

DIS2018TatsumiNITTA_v2.pdf

33 Measurements of Vector boson fusion with the ATLAS detector

The most recent results on the production of single W and Z bosons with two jets at high invariant mass at centre-of-mass energies of 7, 8 and 13 TeV are presented. Integrated and differential cross sections are measured in many different phase space regions with varying degree of sensitivity to the electroweak production in vector boson fusion. The cross section for the electroweak W boson production has been extracted for both integrated and for the first time differential distributions. The results are compared to state-of-the-art theory predictions and are used to constrain anomalous gauge couplings.

Speaker: Philippe Calfayan (Indiana University (US))

pcalfayan_dis2018.pdf

34 Multiboson production at CMS

The production of massive vector boson pairs is a key process for the understanding of the non-abelian gauge structure of the standard model and for the comprehension of the electroweak symmetry breaking mechanism. In this presentation, we will report the most recent inclusive and differential measurements of multiboson production with data collected by the CMS. The recent study of the production of vector boson pairs with the presence of two jets in the event will be presented as well. It allows to measure the electroweak production of vector bosons in association with jets, in particular made up through vector boson scattering (VBS) processes.

Speaker: Andrew Michael Levin (Peking University (CN))

DIS_2018_Multiboson_vAsPresented.pdf

WG6: Spin and 3D structure: Session 1

35 Recent Transverse Spin Measurements in pp Collisions with STAR

The STAR Collaboration at RHIC is exploring the partonic origin of the proton spin with a broad range of measurements in polarized pp collisions. STAR measurements of the transverse single-spin asymmetry, A_N, for W boson production provide the first experimental investigation of the non-universality of the Sivers function. Precise follow-up measurements of A_N for direct photon production, Drell-Yan di-electron production, and W
boson production are underway that will both provide a definitive test of the non-universality and constrain evolution of transverse-momentum-dependent distributions (TMDs) over a very wide Q^2 range. STAR measurements of interference fragmentation functions and the transverse single-spin dependence of the azimuthal modulation of pions in
jets provide the first observations of transversity in pp collisions. The results enable tests of universality and factorization-breaking effects for TMDs in hadronic interactions. Additional transverse modulations provide limits on gluon linear polarization and the twist-3 analog of the gluon Sivers distribution. The current status of these analyses and the prospects to extend them in the near future will be discussed.

Speakers: Carl Gagliardi (Texas A&amp;M University), Carl Gagliardi (Texas A&M University)

DIS2018_Gagliardi.pdf

36 Measurement of longitudinal and transverse target polarization dependent azimuthal asymmetries in muon-p SIDIS processes at COMPASS

COMPASS is a fixed target experiment located at the M2 beamline of the SPS accelerator at CERN. One of the most important objectives of the experiment is the study of the spin structure of the nucleon. Within the QCD parton model approach, the quark structure of the nucleon spin can be parametrized in terms of quark transverse momentum dependent (TMD) parton distribution functions (PDFs) while the hadronization mechanism is described by Fragmentation Functions (FFs). In the experiment, specific convolutions of the TMD PDFs and FFs can be accessed through the measurement of longitudinal and transverse nucleon-spin-dependent azimuthal asymmetries of charged hadrons produced in semi-inclusive deep inelastic lepton-nucleon scattering (SIDIS) processes. Between 2002 and 2011 COMPASS has performed a series of dedicated data-takings using 160-200 GeV/c polarized muons scattering off longitudinally or transversely polarized deuteron ($^6LiD$) and proton ($NH_3$) targets. The whole set of target spin-dependent azimuthal asymmetries present in the SIDIS cross-section has been extracted.
In this talk recent COMPASS results obtained for proton spin-dependent azimuthal asymmetries will be presented along with former results obtained by other collaborations and relevant theoretical model predictions.

Speaker: Dr Bakur Parsamyan (University of Turin and INFN (IT))

Parsamyan_DIS2018.pdf

37 Probing the transverse single spin asymmetry in the inelastic $J/\Psi$ photoproduction at hadronic colliders

In this contribution we investigate the transverse single spin asymmetry in the inelastic $J/\Psi$ photoproduction in $p^\uparrow p$ and $p^\uparrow A$ collisions at RHIC energies. At leading order this process probes the gluon Sivers function. We predict large values for the cross sections, which indicates that its experimental analysis is, in principle, feasible. The rapidity dependence of the single spin asymmetry is presented. We obtain that the asymmetry is strongly dependent on the model used for the gluon Sivers function and that it can be probed by the analysis of the $J/\Psi$ production at forward rapidities. Our results indicate that a future experimental analysis of this process can be useful to constrain the gluon Sivers function.

Speaker: Victor Gonçalves (Universidade Federal de Pelotas)

Talk_Sivers_Dis18.pdf

38 Suppression of gluon polarization in angular asymmetries

First we perform a phenomenological analysis of the cos 2φ azimuthal asymmetry in virtual photon plus jet production induced by the linear polarization of gluons in unpolarized pA collisions. Employing a small-x model input distribution, the asymmetry is found to be strongly suppressed under TMD evolution, but still remains sufficiently large to be measurable in the typical kinematical region accessible at RHIC or LHC at moderate photon virtuality, whereas it is expected to be negligible in Z/W-jet pair production at LHC. We also investigate the energy evolution of the dipole type T-odd gluon TMDs inside a transversely polarized hadron, which unify at small x. The preliminary results shows that these TMDs are also suppressed under TMD evolution.

Speaker: Yajin Zhou (Shandong University)

cos2phi_DIS2018.pdf

39 The complete twist-4 contributions to the SIDIS process $e^- N\to e^- q(jet) X$ at high energies

The talk will present the complete twist-4 result for the semi-inclusive deeply inelastic scattering $e^- N \to e^-qX$ with polarized electron and proton beams at the tree level of pQCD. The calculations have been carried out using the formulism obtained after collinear expansion where the multiple gluon scattering are taken into account and gauge links are obtained automatically in a systematical way. The results show in particular that there are twist-4 contributions to all the eight twist-2 structure functions for $e^- N \to e^-hX$ that correspond to the eight twist-2 transverse momentum dependent parton distribution functions. Such higher twist effects could be very significant and therefore have important impacts on extracting these three-dimensional parton distribution functions from the asymmetry data on $e^- N \to e^-hX$. The talk will first show the formulism obtained using collinear expansion then present the results for the structure functions and the azimuthal asymmetries. At the end, the talk will present also a discussion of the results obtained and a suggestion of an approximate way for a rough estimation of such higher twist contributions.

References
[1] Shu-yi Wei, Yu-kun Song, Kai-bao Chen, Zuo-tang Liang, Twist-4 contributions to semi-inclusive deeply inelastic scatterings with polarized beam and target, Phys. Rev. D95, 074017 (2017).
[2] Yu-kun Song, Jian-hua Gao, Zuo-tang Liang and Xin-Nian Wang, Azimuthal asymmetries in semi-inclusive DIS with polarized beam and/or target and their nuclear dependences, Phys. Rev. D89, 014005 (2014).
[3] Zuo-tang and Xin-Nian Wang, Azimuthal and single spin asymmetry in deep-inelastic lepton-nucleon scattering, Phys. Rev. D75, 094002 (2007).

Speaker: Prof. Zuo-tang Liang (Shandong University)

2018KobeDIS.pdf

WG7: Future of DIS

40 Overview of EIC physics goals

The newly proposed Electron-Ion Collider (EIC) with its unique capability to collide polarized electrons with polarized protons and light ions at unprecedented luminosity, and with almost all elements of heavy nuclei at high energy, will be the ideal and much needed facility to explore the emerging science of nuclear femtography, and take us to the next frontier of the Standard Model of physics. In this talk, I will provide an overview of EIC physics goals and challenges to reach them.

Speaker: Dr Jianwei Qiu (Jefferson Lab)

Qiu-DIS2018-WG7-EIC.pdf

41 VHEeP: A very high energy electron--proton collider

Based on current CERN infrastructure, an electron--proton collider is proposed at a center-of-mass energy of about 9 TeV. A 7 TeV LHC bunch is used as the proton driver to create a plasma wakefield which then accelerates electrons to 3 TeV, these then colliding with the other 7 TeV LHC proton beam. Although of very high energy, the collider has a modest projected integrated luminosity of 10-100 inverse pb. For such a collider, with a center-of-mass energy 30 times greater than HERA, parton momentum fractions, x, down to about 10^-8 are accessible for photon virtualities, Q^2, of 1 GeV^2. The energy dependence of hadronic cross sections at high energies, such as the the total photon-proton cross section, which has synergy with cosmic-ray physics, can be measured and QCD and the structure of matter better understood in a region where the effects are completely unknown. Searches at high Q^2 for physics beyond the Standard Model will be possible, in particular the significantly increased sensitivity to the production of leptoquarks.

Speaker: Allen Christopher Caldwell (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

2_Caldwell_VHEeP.pdf

42 Pion and Kaon Structure Functions at EIC

Pions and kaons are, along with protons and neutrons, the main building blocks of nuclear matter. The distribution of the fundamental constituents, the quarks and gluons, is expected to be different in pions, kaons, and nucleons. However, experimental data are sparse. As a result, there has been persistent doubt about the behavior of the pion's valence quark structure function at large Bjorken-x and virtually nothing is known about the contribution of gluons. The Electron-Ion Collider with an acceptance optimized for forward physics could provide access to structure functions over a larger kinematic region. This would allow for measurements testing if the origin of mass is encoded in the differences of gluons in pions, kaons, and nucleons, and measurements that could serve as a test of assumptions used in the extraction of structure functions. Measurements at an EIC would also allow to explore the effect of gluons at high x. In this talk we will discuss the prospects of such measurements.

Speaker: Rolf Ent (Jefferson Lab)

3_Ent-pion-kaon-EIC-DIS2018.pdf

43 A Fixed-Target Program at the LHC (AFTER@LHC): where do we stand ?

We review the physics opportunities [1] which are offered by a next generation and multi-purpose fixed-target experiment exploiting the LHC beams in order to study $pp$, $pd$ and $pA$ collisions at $\sqrt{s_{NN}} \sim 115$ GeV as well as Pb$p$ and Pb$A$ collisions at $\sqrt{s_{NN}} \sim 72$ GeV.

We propose two possible implementations, namely with an internal (polarised) gas target or with a "splitted" beam by a bent crystal which both provide typical instantaneous luminosities [1,2] for $pp$ and $pA$ collisions which surpass that of RHIC by more than 3 orders of magnitude and are comparable to those of the LHC collider mode.

We also discuss our most recent figures of merit [3,4,5] based on two already existing detector set-ups, the LHCb and the ALICE detectors.

References:

[1] S. J. Brodsky, F. Fleuret, C. Hadjidakis and J. P. Lansberg, Phys. Rept. 108 522 (2013) 239. For a complete list of references see http://after.in2p3.fr/after/index.php/Recent_published_ideas_in_favour_of_AFTER@LHC

[2] C. Barschel, P. Lenisa, A. Nass, E. Steffens. Adv.High Energy Phys. 2015 (2015) 463141.

[3] L. Massacrier, B. Trzeciak, F. Fleuret, C. Hadjidakis, D. Kikola, J.P. Lansberg, H.-S. Shao. Adv.High Energy Phys. 2015 (2015) 986348.

[4] B. Trzeciak, C. Da Silva, E.G. Ferreiro, C. Hadjidakis, D. Kikoła, J.P. Lansberg, L. Massacrier, J. Seixas, A. Uras, Z. Yang Few Body Syst. 58 (2017) 148

[5] D. Kikoła, M. G. Echevarria, C. Hadjidakis, J.P. Lansberg (Orsay, IPN), C. Lorcé, L. Massacrier, C. Marques Quintans, A. Signori, B. Trzeciak. Few Body Syst. 58 (2017) no.4, 139

Speaker: Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)

AFTER-DIS_170418.pdf

11:00 Coffee

WG1: Structure Functions and Parton Densities: Vector-boson and gamma production

44 Measurement of photon production cross sections with the ATLAS detector

The production of prompt isolated photons at hadron colliders provides a stringent test of perturbative QCD and can be used to probe the gluon density function of the proton. The ATLAS collaboration has performed precise measurements of the inclusive production of isolated prompt photons at a center-of-mass energy of 13 TeV, differential in both rapidity and the photon transverse momentum. In addition, the integrated and differential cross sections for isolated photon pair production and -most recently for the first time - the tri-photon production at 8 TeV have been measured. The results are compared with state-of-the-art theory predictions at NLO in QCD and with predictions of several MC generators. In particular the results of the tri-photon production highlight interesting discrepancies to advanced theory calculations.

Speaker: Bruno Lenzi (CERN)

BL_DIS_ATLASphotons_2018_04_17.pdf

45 W, Z and top production measurements at LHCb

Albeit initially designed for b-physics, LHCb has demonstrated to function very well as a general-purpose forward detector, covering the pseudo-rapidity range 2 < eta < 5.
Several measurements concerning the production of W, Z and top have been performed using LHCb data. A selection of relevant results will be presented, highlighting LHCb's new measurement of tt production at \sqrt{s}=13 TeV.

Speaker: Patrick Robbe (Université Paris-Saclay (FR))

LHCb_DIS_Z_17Apr2018.pdf

46 Differential measurements of the Drell-Yan cross-sections

Measurements of the Drell-Yan production of W and Z/gamma bosons at the LHC provide a benchmark of our understanding of perturbative QCD and probe the proton structure in a unique way. The ATLAS collaboration has performed high precision measurements at center-of-mass energies of 7 and 8 TeV. The measurements are performed for W+, W- and Z/gamma bosons integrated and as a function of the boson or lepton rapidity and the Z/gamma* mass. ATLAS also performed a precise triple differential cross-section measurement as a function of Mll, dilepton rapidity and cosθ∗ defined in the Collins-Soper frame. This measurement provides sensitivity to the PDFs and the Z forward-backward asymmetry, AFB.

Speaker: Ulla Blumenschein (University of London (GB))

DIS_UB.pdf

47 Studies of photon production in association with jets at the ATLAS detector

The production of prompt photons in association with jets in proton–proton collisions provides a testing ground for perturbative QCD (pQCD) with a hard colourless probe less affected by hadronisation effects than jet production. The measurements of the angular correlations between the photon and the jets can be used to probe the dynamics of the hard-scattering process. We present here a cross-section measurement using final states with at least one, two or three hadronic jets in addition to an isolated photon, differential in a wide range of kinematic variables describing the photon+jet production dynamic. Colour-coherence effects were investigated in events with a photon accompanied by two jets. Moreover, we present the latest results on the measurement of isolated photons with jets at 13 TeV as well as on the production of photon-pairs in association with jets. We will also present for the first time measurements on the differential cross sections of isolated-photon plus heavy-flavour jet production at 8 TeV. The results are compared to recent theoretical predictions.

Speaker: Mark Stockton (University of Oregon (US))

MarkStockton_DIS.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 2

48 Searches for ttH production at CMS

Recent results on associated top Higgs production at CMS are reviewed.

Speaker: Aruna Nayak (National Institute of Science Education and Research (IN))

tth_dis2018.pdf

49 Evidence for Higgs boson production in association with a ttbar pair

The search for the production of the Higgs Boson with a pair of top-anti-top quarks is both very important and very challenging. This talks presents the analyses using Higgs boson decays to bbbar pairs, to two Z bosons, to other multi-lepton final states, and to a pair of photons, using 36 fb-1 of pp collision data collected at 13 TeV, as well as their combined results.

Speaker: Arthur Chomont (Université Paris-Saclay (FR))

ttH_DIS2018_achomont.pdf

50 New NLOPS predictions for b-jet production in association with a pair of top quarks at the LHC

Measurements of $t\bar{t}H$ production in the $H \to b\bar{b}$ channel depend in a critical way on the theoretical uncertainty associated with the irreducible $t\bar{t}+b$-jet background. In this paper, analysing the various topologies that account for b-jet production in association with a $t\bar{t}$ pair, we demonstrate that the process at hand is largely driven by final-state $g \to b\bar{b}$ splittings. We also show that in five-flavour simulations based on $t\bar{t}$+multi-jet merging $b$-jet production is mostly driven by the parton shower, while matrix elements play only a marginal role in the description of $g \to b\bar{b}$ splittings. Based on these observations we advocate the use of NLOPS simulations of $pp \to t\bar{t}b\bar{b}$ in the four-flavour scheme, and we present a new POWHEG generator of this kind. Predictions and uncertainties for $t\bar{t}+b$-jet observables at the 13 TeV LHC are presented both for the case of stable top quarks and with spin-correlated top decays. Besides QCD scale variations we consider also theoretical uncertainties related to the POWHEG matching method and to the parton shower modelling, with emphasis on $g \to b\bar{b}$ splittings. In general, matching and shower uncertainties turn out to be remarkably small. This is confirmed also by a tuned comparison against Sherpa+OpenLoops.

Speaker: Tomas Jezo (University of Zurich)

TJezo.pdf

WG4: Hadronic and Electroweak Observables: Session 2

51 Simulations of photo-nuclear dijets with PYTHIA 8 and their sensitivity to nuclear PDFs

In ultra-peripheral heavy-ion collisions the ions encounter with such a large impact parameter that no strong interaction can take place. However, the photons produced by the colliding ion can interact either with the other nucleus or with a photon from the another nucleus. The former corresponds to photoproduction studied earlier in electron-proton collisions at HERA but with a nuclear target. This provides an unique opportunity to study the nuclear modifications of the PDFs with the photo-nuclear processes measured in lead-lead collisions at the LHC. First preliminary results for photo-nuclear dijets were recently published by ATLAS and plenty of more data are expected in near future. In this talk, I will first present our recent implementation of photoproduction processes in PYTHIA 8 general-purpose Monte-Carlo event generator. The resulting simulations are compared to charged-hadron and dijet production data from different HERA experiments and the theoretical uncertainties of the framework are quantified. Then I will discuss how the relevant part of the photon flux from heavy-ions is obtained using equivalent photon approximation and present predictions for photo-nuclear dijet cross section at the LHC. To estimate the potential of this data to further constrain the nuclear PDFs, the expected statistical uncertainty based on LHC luminosity is compared to uncertainties in current nuclear PDF analyses.

Speaker: Dr Ilkka Helenius (Tübingen University)

Helenius_DIS.pdf

52 Muon identification and performance in the ATLAS experiment

Muon reconstruction and identification play a fundamental role in many analyses of central importance in the LHC run-2 Physics pro- gramme. The algorithms and the criteria used in ATLAS for the re- construction and identification of muons with transverse momentum from a few GeV to the TeV scale will be presented. Their performance is measured in data based on the decays of Z and J/ψ to pair of muons, that provide a large statistics calibration sample. Reconstruction and identification efficiencies are evaluated, as well as momentum scales and resolutions, and the results are used to derive precise MC simula- tion corrections. Isolation selection criteria and their performances in presence of high pileup will also be presented.

Speaker: Sebastien Rettie (University of British Columbia (CA))

2018_04_17_Sebastien_Rettie_DIS_2018_v4.pdf

53 Further studies of isolated photon production with a jet in deep inelastic scattering at HERA

Isolated photons with high transverse energy have been studied in
deep inelastic $ep$ scattering with the ZEUS detector at HERA, using
an integrated luminosity of $326\, \mathrm{pb}^{-1}$ in the range of
exchanged-photon virtuality $10 - 350 \,\, \mathrm{GeV}^2$. Outgoing
isolated photons with transverse energy $4< E_T^\gamma< 15$ GeV and
pseudorapidity $-0.7 < \eta^\gamma < 0.9$ were measured with accompanying
jets having transverse energy and pseudorapidity $2.5 < E_T^{\rm jet} <35$ GeV
and $-1.5< \eta^{\rm jet} < 1.8$, respectively. Differential cross sections
are presented for the following variables: the fraction of the
incoming photon energy and momentum that is transferred to the
outgoing photon and the leading jet; the fraction of the incoming
proton energy transferred to the photon and leading jet; the differences in
azimuthal angle and pseudorapidity between the outgoing photon and the
leading jet and between the outgoing photon and the scattered
electron. Comparisons are made with theoretical predictions: a
leading-logarithm Monte Carlo simulation, a next-to-leading-order QCD
prediction, and a prediction using the $k_T$-factorisation approach.

Speaker: Katarzyna Wichmann (Deutsches Elektronen-Synchrotron (DE))

kwichmann-dis18-ppDIS.pdf

54 Study of K^0_S pair production in single-tag two-photon collisions at Belle

We report a measurement of the cross section for K^0_S pair production in single-tag two-photon collisions, gamma gamma → K^0_S K^0_S for Q^2 up to 30 GeV^2, where Q^2 is the negative of the invariant mass squared of the tagged photon. The measurement covers the kinematic range 1.0 GeV < W < 2.6 GeV and |cos theta|<1.0 for the total energy and kaon scattering angle, respectively, in the gamma* gamma center-of-mass system. These results are based on a data sample of 759 fb-1 collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. For the first time, the transition form factor of the f'2(1525) meson is measured separately for the helicity-0, -1, and -2 components and also compared with theoretical calculations. Finally, the partial decay widths of the chi_c0 and chi_c2 mesons are measured as a function of Q^2.

Speaker: Sadaharu Uehara (KEK)

dis_uehara_18h1.pdf

WG5: Physics with Heavy Flavours: Session 2

Excursion instructions

55 Single Top quark production cross section using the ATLAS detector at the LHC

Measurements of single top-quark production in proton-proton collisions are presented based on the 8 TeV and 13 TeV ATLAS datasets. In the leading order process, a W boson is exchanged in the t-channel. The cross-section for the production of single top-quarks and single anti-top-quarks, their ratio, as well as differential cross-section measurements are also reported. These analyses include limits on anomalous contributions to the Wtb vertex and measurement of the top quark polarization. Measurements of the inclusive and differential cross-sections for the production of a single top quark in association with a W boson, the second largest single-top production mode, are also presented. Finally, evidence for s-channel single-top production in the 8 TeV ATLAS dataset is presented. All measurements are compared to state-of-the-art theoretical calculations.

Speaker: Oscar Estrada Pastor (Univ. of Valencia and CSIC (ES))

DIS2018_Oscar.pdf

56 Rare top quark production in CMS: ttW, ttZ, ttgamma, tZ, tgamma, and tttt production

A comprehensive set of measurements of top quark pair and single top quark production in association with EWK bosons (W, Z or ɣ) is presented. The results are compared to theory predictions and re-interpreted as searches for new physics inducing deviations from the standard model predictions using an effective field theory approach. The status of the search for four top quark production, to which the LHC experiments are starting to be sensitive, and that has important BSM re-interpretations, is also reported.

Speaker: Su Yong Choi (Korea University (KR))

Rare tt-v1.0.pdf

57 Measurements of ttbar+X using the ATLAS detector

The large centre-of-mass energy available at the proton-proton collider LHC allows for the copious production of top quark pairs in association with other final state particles at high transverse momenta. The ATLAS experiment has measured several final state observables that are sensitive to additional radiation in top anti-top quark final states. Results on the top production in association with W and Z bosons are presented as well as top pair production with a photon. Analyses probing top pair production with additional QCD radiation are also presented, including top pair production in association with additional heavy flavour jets. These measurements are compared to predictions of modern Monte Carlo generators based on NLO QCD matrix element or LO multi-leg matrix elements.

Speaker: Hasib Ahmed (The University of Edinburgh (GB))

ATLAS_ttX_DIS2018.pdf

58 Top quark pair property measurements using the ATLAS detector at the LHC

Precise measurements of the properties of the top quark test the Standard Model (SM) and can be used to constrain new physics models. As it may be significantly enhanced by the presence of new physics, the ttbar production charge asymmetry is measured inclusively and differentially using the 8 TeV ATLAS dataset using both the lepton+jets and dilepton channels, including a dedicated measurement for highly boosted top-quarks. The top-quark is predicted in the SM to decay almost exclusively into a W boson and a b-quark. We present a wide range of searches for non-SM top quark decays using the 13 TeV ATLAS datasets, including t->q H and t->q Z. In addition, measurements of the spin correlation and colour flow in ttbar production are presented.

Speaker: Stefan Kluth (Max-Planck-Institut fur Physik (DE))

dis2018_talk.pdf

WG6: Spin and 3D structure: Session 2

59 Probing gluon TMDs with quarkonia

In this talk, I will discuss the relevance of using quarkonium-hadroproduction data in order to study the gluon TMDs in unpolarised protons. I will discuss the case of single $\eta_c$ production as well as that of $J/\psi(\Upsilon)+\gamma$ and $J/\psi$ pairs. In particular, I will discuss our first extraction of $f_1^g$ using the di-$J/\psi$ LHCb data and argue that $h_1^{\perp g}$ can be extracted in the near future with data taken in the CMS and ATLAS acceptances. I will also discuss how the newly introduced matching procedure based on an inverse-error weighting can help connect such studies with computations made in the collinear factorisation.

Speaker: Jean-Philippe Lansberg (IPN Orsay, Paris Sud U. / IN2P3-CNRS)

Lansberg-DIS-2018-140418.pdf

60 Measurement of transverse-spin-dependent azimuthal asymmetries in Drell-Yan process at COMPASS

The first measurement of transverse-spin-dependent azimuthal
asymmetries in the pion-induced Drell-Yan (DY) process will be
presented, which was reported in PRL 119, 112002. We use the CERN SPS
190  GeV/c pi- beam and a transversely polarized ammonia target.
Three azimuthal asymmetries giving access to different
transverse-momentum-dependent (TMD) parton distribution functions
(PDFs) are extracted using dimuon events with invariant mass between
4.3  GeV/c2 and 8.5  GeV/c2. Within the experimental uncertainties,
the observed sign of the Sivers asymmetry is found to be consistent
with the fundamental prediction of quantum chromodynamics (QCD) that
the Sivers TMD PDFs extracted from DY have a sign opposite to the one
extracted from semi-inclusive deep-inelastic scattering (SIDIS) data.
We present two other asymmetries originating from the pion
Boer-Mulders TMD PDFs convoluted with either the nucleon transversity
or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was
obtained at a hard scale comparable to that of these DY results. This
opens the way for possible tests of fundamental QCD universality
predictions.

Speaker: Dr Michela Chiosso (University of Torino and INFN)

DIS2018_MChiosso.pdf

61 Transverse Single Spin Asymmetries of charged hadron from p+p and p+Au collisions in PHENIX

Transverse single-spin asymmetries (TSSA) of light hadron production from $p^{\uparrow}+p$ collisions provide valuable information on the spin structure of the nucleon. TSSA in the process $p^\uparrow + p \rightarrow h+X$ has been described in terms of twist-3 spin-dependent three-parton correlation functions, or twist-3 fragmentation functions in the QCD collinear factorization approach. In addition, studying the TSSA for inclusive hadron production in $p^{\uparrow}+A$ collisions can give new insight on the underlying mechanism because different contributions to the TSSA are affected differently by the saturation effect in large nuclei. We will report a recent study on the TSSA of charged hadron production at forward and backward ($1.4<|\eta|<2.4$) rapidity over the the transverse momentum range of $1.25

Speaker: Jeongsu Bok (New Mexico State University)

DIS18_W6_April17_PHENIX_hadronAN_JeongsuBok.pdf

62 Orbital angular momentum distributions at small-x

We study the orbital angular momentum (OAM) of quarks and gluons in the nucleon in the small-x region. We argue, in two different ways, that the gluon OAM significantly cancels the gluon helicity distribution at small-x. A similar cancellation occurs also in the quark sector.

Speaker: Yoshitaka Hatta (Japan/Yukawa Institute)

DIS2018Hatta.pdf

DIS2018Hatta.pptx

WG7: Future of DIS: Session 1

63 eRHIC - an electron - Ion collider at BNL

In this talk I will summarize the current design status of eRHIC with special emphasis on the integration of the EIC Physics requirements into the accelerator design.

Speaker: elke-caroline Aschenauer (BNL)

eca.eRHIC.DIS.pptx

64 Status of JLEIC and its interaction region design

An Electron Ion Collider (EIC) has been identified in the Nuclear Physics Long Range Plan as the highest-priority facility for new construction. This talk presents an overview and status of the Jefferson Lab design of an EIC (JLEIC). It features frequent collisions of small electron and ion bunches providing a luminosity of $10^{33}$-$10^{34}$ cm$^{-1}$s$^{-1}$ in a broad range of the center-of-mass energy. The small size of ion bunches is maintained against intra-beam scattering by a novel high-energy bunched beam electron cooling system. The figure-8 shape of the electron and all ion rings allows for preservation and ease of manipulation of the electron polarization and the spin of any ion species (p, d, $^3$He, Li, etc.). The interaction region is designed to accommodate a full-acceptance detector with complete coverage and geometry tagging in the forward and ultra-forward directions. The talk highlights recent progress on the JLEIC accelerator design with an emphasis on the integrated interaction region design.

Speaker: V.S. Morozov (Jefferson Lab, Newport News, VA)

2_Morozov_JLab_and_IR_status_15apr18.pdf

65 Electron Ion Collider in China

In this talk I will present an overview of the
scientific opportunities that would be addressed by the Electron-Ion-Collider
in China (EicC).

The polarized EicC will open up a new window to study
the one and three dimensions (3D) nucleon structure for both sea and valence
quarks and help fully understand the strong interaction.

In the first phase the EicC will be 3~ 5 GeV polarized
electron on 12 ~ 25 GeV polarized proton (and ions about 12 GeV/nucleon), with
luminosity ~10^{33} /cm2/s . We will
focus on discuss the EIC plan and its exciting physics potentials.

Speaker: Xurong Chen

3_DIS2018-Xurong Chen.pdf

66 TOPSiDE: A detector concept for the EIC

We report on a detector concept, TOPSiDE, being developed for the EIC
Electron-Ion Collider. TOPSiDE aims a the detection and identification
of all particles created in electron-proton/ion collisions at the EIC
while achieving the best possible momentum/energy resolution. The
measurement of hadronic jets exploits the advantages offered by Particle
Flow Algorithms (PFAs), which in turn require imaging calorimetry. Particle
identification is achieved through time-of-flight measurements in the tracker
and the electromagnetic calorimeter, necessitating the application of
ultra-fast silicon sensors. In the forward (hadron) direction the particles
are identified with a Cerenkov detector covering forward angles up to 10
degrees and a dipole or toroidal magnet for momentum measurement. The talk
presents the detector concept, the status of its simulation software, first
studies performed with a completed simulation tool chain, and the status
of the detector R&D related to the novel and challenging aspects of the
concept detector.

Speaker: Jose Repond (Argonne National Laboratory)

4_EIC_TOPSiDE_Kobe_Apr_2018.pdf

67 Medium-energy Nuclear Physics at RHIC with sPHENIX and an sPHENIX Forward Upgrade

The proposed sPHENIX detector at the Relativistic Heavy Ion Collider (RHIC), together with RHIC’s unique capabilities to collide polarized protons and heavy nuclei, will open the door to exciting new measurements to enhance our understanding of quantum chromodynamics (QCD). These measurements will reveal more about how partons behave in a nuclear environment, explore spin-spin and spin-momentum correlations in the nucleon, and provide data to investigate effects of non-universality. A potential upgrade to sPHENIX with forward instrumentation could significantly enhance these physics capabilities. The medium-energy nuclear physics program for the proposed sPHENIX midrapidity detector as well as the enhanced program enabled with forward upgrades will be presented.

Speaker: Dr itaru nakagawa (RIKEN)

DIS2018_fsPHENIX_180411.pdf

DIS2018_fsPHENIX_180411.pptx

13:00 Lunch

Lunchbox provided

WG1: Structure Functions and Parton Densities: Parton distribution functions (1)

68 Strange and non-strange quark distributions from the collider data

Results of the QCD analysis of a variety of the
hard-scattering data is over-viewed with a particular
focus on determination of the quark distributions in the nucleon.
A potential of the recent precise data collected at the LHC
for the problem of quark species disentangling is discussed and
compared to the impact of the low-energy fixed-target data
Finally, remaining challenges and potential improvements in the field are outlined.

Speaker: Serguei Alekhin (State Res.Center of Russian Feder. Inst.f.High Energy Phys. (IFVE))

alekhin.pdf

69 Update of MMHT PDFs

We discuss the most recent updates to the PDFs obtained in the MMHT framework.
We study of the impact of the most recent LHC data and in particular focus on issues in finding good fits to these data given the very high precision now
available and the implications for PDFs and their uncertainties.

Speaker: Robert Samuel Thorne (University College London (UK))

DIS18.pdf

70 Progress on CTEQ-TEA PDFs

We present the recent progress on parton distribution functions (PDF) of the proton from the CTEQ-TEA collaboration.

Speaker: Dr Tie-Jiun Hou (Xinjiang University)

DIS2018_Progress_on_CTEQ-TEA_PDFs_TJHou.pdf

71 NNPDF3.1: Parton distributions from high-precision collider data

We present a new set of parton distributions, NNPDF3.1, which updates NNPDF3.0, the first global set of PDFs determined using a methodology validated by a closure test. The update is motivated by recent progress in methodology and available data, and involves both. On the methodological side, we now parametrize and determine the charm PDF alongside the light quarks and gluon ones, thereby increasing from seven to eight the number of independent PDFs. On the data side, we now include the D0 electron and muon W asymmetries from the final Tevatron dataset, the complete LHCb measurements of W and Z production in the forward region at 7 and 8 TeV, and new ATLAS and CMS measurements of inclusive jet and electroweak boson production. We also include for the first time top-quark pair differential distributions and the transverse momentum of the Z bosons from ATLAS and CMS. We investigate the impact of parametrizing charm and provide evidence that the accuracy and stability of the PDFs are thereby improved. We study the impact of the new data by producing a variety of determinations based on reduced datasets. We find that both improvements have a significant impact on the PDFs, with some substantial reductions in uncertainties, but with the new PDFs generally in agreement with the previous set at the one sigma level. The most significant changes are seen in the light-quark flavor separation, and in increased precision in the determination of the gluon. We explore the implications of NNPDF3.1 for LHC phenomenology at Run II, compare with recent LHC measurements at 13 TeV, provide updated predictions for Higgs production cross-sections and discuss the strangeness and charm content of the proton in light of our improved dataset and methodology. The NNPDF3.1 PDFs are delivered for the first time both as Hessian sets, and as optimized Monte Carlo sets with a compressed number of replicas.

Speaker: Nathan Hartland (NIKHEF)

hartland.pdf

72 QCD analysis of the ATLAS and CMS W and Z cross-section measurements and implications for the strange sea density

In the present paper, the ATLAS inclusive $W^{\pm}$ and $Z$ boson production data are analysed together with the CMS inclusive $W^{\pm}$ and $Z$ boson production data to investigate any possible tensions between the data sets and to determine the strange sea fraction, within the framework of a parton distribution function fit at next-to next-to leading order in perturbative QCD.

Speaker: Katarzyna Wichmann (Deutsches Elektronen-Synchrotron (DE))

kwichmann-dis18-strange.pdf

73 Impact of CMS measurements on Proton Structure and QCD parameters

The sensitivity of CMS measurements to Parton Distribution Functions, strong coupling constant and treatment of heavy flavours in QCD analyses is presented. CMS data collected at various center-of-mass energies and their impact on the PDFs are presented. Measurements of cross sections of jet and to-quark pair production are in particular sensitive to the gluon distribution in the proton and the strong coupling, while the electroweak boson production - inclusive or associated with charm or beauty quarks give insight into the flavour separation of the proton sea and give hints to the treatment of heavy quarks in PDF-related studies.

Speaker: Svenja Karen Pflitsch (Deutsches Elektronen-Synchrotron (DE))

CMS_Protonstructure_Measurements.pdf

WG2: Small-x and Diffraction: Session 2

74 Measurements of the underlying-event properties and hadron production with the ATLAS detector

A correct modelling of the underlying event in proton-proton collisions is important for the proper simulation of kinematic distributions of high-energy collisions. The ATLAS collaboration extended previous studies at 7 TeV with a leading track or jet or Z boson by a new study at 13 TeV, measuring the number and transverse-momentum sum of charged particles as a function of pseudorapidity and azimuthal angle in dependence of the reconstructed leading track. These measurements are sensitive to the underlying-event as well as the onset of hard emissions. The results are compared to predictions of several MC generators. Further studies shed light on the correlated hadron production, which are an important source of information about the early stages of hadron formation, not yet understood from first principles. In this presentation, we will discuss Bose-Einstein correlations measured with the ATLAS detector along with an analysis of the momentum difference between charged hadrons in high–energy proton–proton collisions. The latter allows the investigation of observables sensitive to the predictions of the quantized string model.

Speaker: Mario Campanelli (University College London (UK))

AtlasTalk.pdf

75 Minimum Bias and UE measurements at CMS

We present results on the measurement of the underlying event at 13 TeV and recent results from Minimum Bias measurements with the CMS experiment.

Speaker: Gabor Veres (Eotvos Lorand University (HU))

DIS18MB2.pdf

76 QCD Monte-Carlo model tuning studies with CMS data at 13 TeV

New CMS PYTHIA 8 event tunes are presented. The new tunes are obtained using minimum bias and underlying event observables using Monte Carlo configurations with consistent parton distribution functions and strong coupling constant values in the matrix element and the parton shower. Validation and performance studies are presented by comparing the predictions of the new tune to various soft- and hard-QCD measurements at 7, 8 and 13 TeV with CMS.

Speaker: Daniela Dominguez Damiani (DESY)

DIS.pdf

77 Study of hard double parton scattering in four-jet events with the ATLAS detector

Inclusive four-jet events produced in proton--proton collisions at a center-of-mass energy of 7 TeV have been analyzed for the presence of hard double parton scattering collected with the ATLAS detector. The contribution of hard double parton scattering to the production of four-jet events has been extracted using an artificial neural network. The assumption made was that hard double parton scattering can be represented by a random combination of dijet events. In addition, a sample enriched with double parton scattering events was extracted and several characteristics of these events were studied. The measurements have been compared to different MC generator predictions.

Speaker: Michel Vetterli (Simon Fraser University (CA))

vetterli-DIS-2018.pdf

78 Double parton scattering measurements at CMS

We present recent results on Double Parton Scattering (DPS) studies using data collected during Run 1 and Run 2 of the LHC with the CMS experiment. Double parton scattering is investigated in several final states including vector bosons and multi-jets. Measurements of observables designed to highlight the DPS contribution are shown and compared to MC predictions from models based on multiple partonic interactions (MPI) phenomenology.

Speaker: Gabor Veres (Eotvos Lorand University (HU))

DIS18DPS.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 2a

WG4: Hadronic and Electroweak Observables: Session 3

79 Colour Rearrangement for Dipole Showers

In a recent article (1801.06113), we discussed the possibility of using simple matrix elements to produce probabilities of rearranging the colour chains in dipole shower algorithms. Due to the changed density of larger and smaller dipole chains, particle spectra and standard observables are modified. In the talk, I will discuss the idea and the consequences for tuning and the soft model of event generators. Comparisons to collider data from LEP, HERA and LHC are included.

Speaker: Johannes Bellm (Lund)

Colorea_Talk.pdf

80 Exploring improvements to the fitting of the strong coupling constant through means of jet substructure techniques

Over the years many different types of fits for the strong coupling constant have been performed. However one high precision result that currently significantly differs from the world average are results from event shapes at electron positron colliders. One possible source for the difference in these results could be the degeneracy between the fit of the strong coupling constant and non-perturbative parameter. In this talk I will explore the possibility to apply jet substructure techniques, specifically soft drop, in order to break the degeneracy between the non-perturbative parameter and the strong coupling constant.

Speaker: Vincent Theeuwes (University of Goettingen)

VTheeuwes-DIS2018.pdf

81 Jet Substructure Measurements Sensitive to Soft QCD effects with the ATLAS Detector

Calculations of jet substructure observables which are accurate beyondleading-logarithmic accuracy have recently become available. Such observables are significant not only for probing a new regime of QCD at a hadron collider, but also for improving the understanding of jet substructure properties that are used in many studies at the Large Hadron Collider. In this talk, we discuss first measurement of jet substructure quantities at a hadron collider, calculated at next-to-next-to-leading-logarithm accuracy. The soft drop mass is measured in dijet events with the ATLAS detector at 13 TeV, unfolded to particle-level and compared to Monte Carlo simulations. In addition, we present a measurement of the splitting scales in the kt jet-clustering algorithm for final states containing a Z-boson candidate at a centre-of-mass energy of 8 TeV. The data are also corrected for detector effects and are compared to state-of-the-art Monte Carlo predictions.

Speaker: Trisha Farooque (Michigan State University (US))

DIS_JSS_QCD.pdf

82 Identification of boosted hadronically decaying particles with jet substructure in ATLAS Run-2

In order to exploit the abundance of high momentum heavy particles produced at LHC (top, W/Z and Higgs) and decaying hadronically, the study of jet substucture has become increasingly important throughout a wide array of searches and measurements. The latest ATLAS results in terms of jet substructure measurements and calibrations are presented including studies of performance sensitivity to pileup, with several grooming algorithms and recently developed constituent level pile up mitigation techniques.

Speaker: Jason Robert Veatch (Georg August Universitaet Goettingen (DE))

jveatch_dis2018_tagging.pdf

83 Measurements of event properties and correlations in multijet events in CMS

We present results on measurements of characteristics of events with jets, from jet-charge over investigations of shapes to jet mass distributions, and angular correlations in multi-jet events. The measurements are compared to theoretical predictions including those matched to parton shower and hadronization.

Speaker: Armando Bermudez Martinez (CMS-DESY)

DIS_2018_final_Armando.pdf

WG5: Physics with Heavy Flavours: Session 1

Excursion instructions

84 Top quark pair-production cross-section measurements with the ATLAS detector

Measurements of the inclusive and differential top-quark pair cross sections in proton-proton collisions at both 8 and 13 TeV with the ATLAS detector at the Large Hadron Collider are presented. The inclusive measurements reach high precision and are compared to the best available theoretical calculations. Differential measurements of the kinematic properties of the top quark production are also discussed. These measurements, including results using boosted top quarks, probe our understanding of top quark pair production in the TeV regime. The results, unfolded to particle and parton level, are compared to predictions of Monte Carlo generators implementing NLO matrix elements matched with parton showers and NNLO QCD theory calculations.

Speaker: Pavol Bartos (Comenius University (SK))

bartos_contribution1.pdf

85 Precision calculations for top-quark pair production at the LHC

In this work we will present predictions for top-quark pair differential distributions at the LHC13 at NNLO QCD accuracy and including EW corrections. For the latter we include not only contributions of ${\mathcal O}(\alpha_s^2 \alpha)$, but also those of order ${\mathcal O}(\alpha_s \alpha^2)$ and ${\mathcal O}( \alpha^3)$. We will discuss the difference between the additive and multiplicative approach for the combination of QCD and EW corrections. Furthermore we will present results for the inclusive $A_C$ as well as several differential asymmetries at the LHC8. The material presented will be based on the arXiv:1705.04105 and arXiv:1711.03945 papers.

Speaker: Ioannis Tsinikos (UCLouvain)

Ioannis_Tsinikos_DIS2018.pdf

86 Top quark pair and single top t-channel differential cross sections in CMS

Differential measurements of top quark pair and single top quark (t-channel) production cross sections are presented using data collected by CMS at different centre-of-mass energies. The cross sections are measured as a function of various kinematic observables of the top quarks and the jets and leptons of the event final state. The ttbar measurements are extended to the TeV range using jet substructure techniques to exploit the boosted regime. The multiplicity and kinematic distributions of the jets produced in addition to the top quark pair are also investigated. The results are confronted with precise theory calculations.

Speaker: Youn Jung Roh (Korea University (KR))

DIS2018_kobe_youn.pdf

87 Large transverse momentum top production at NLO+NLL accuracy

We present an upgrade of the venerable FONLL code to handle top quark production. Predictions for large transverse momentum distributions at NLO+NLL accuracy are presented. Comparisons to recent experimental data, and to NNLO fixed order predictions and to SCET resummations, as well as to Monte Carlos matched to NLO predictions, are performed. Phenomenological relevance of the large transverse momentum resummation at a future FCC hadron collider is investigated.

Speaker: Matteo Cacciari (LPTHE Jussieu)

top-dis-cacciari.pdf

88 Heavy quark mass effects in associated production

In this talk we introduce a newly developed scheme based on an extension of the 5F flavour scheme, which treats $b$ quarks as massless partons, to include full heavy quark mass dependency. We name this extension five-flavour massive scheme. We implement this scheme at MC@NLO accuracy in Sherpa. We present some results, obtained in this scheme, for $b$ quarks produced in association with a vector boson or a Higgs boson.

Speaker: Davide Napoletano (IPhT, Saclay)

dis18.pdf

WG6-WG7 Joint Session

89 The STAR Cold QCD Physics Program after 2020

The STAR experiment is planning to upgrade the forward rapidity region (2.5 < eta < 4.5) to enable novel measurements in p+p, p+A and A+A collisions. The upgrade is motivated by exploration of cold QCD physics in the very high and low regions of Bjorken x. The current design envisions a Calorimeter System (FCS) that integrates parts of the refurbished PHENIX sampling ECal and a hadronic calorimeter (sandwich iron scintillator plates). In addition to the FCS, a Forward Tracking System (FTS) is also proposed to discriminate the hadron charge sign in p+p and p+A collisions at high momenta p<80 GeV/c. The design combines three Silicon mini-strip disks and four Small-Strip Thin Gap Chamber (sTGC) wheels similar to the ATLAS muon detector upgrade. In addition, STAR's excellent capabilities at midrapidity are upgraded to moderate forward kinematics (|eta| < 1.7) for the Beam Energy Scan (phase II) and beyond. The full set of upgrades will enable key physics opportunities in three broad areas of interest: the dynamics of low and high x partons in cold nuclear matter (CNM);Â modification of fragmentation and hadronization of partons through interactions within CNM; experiments to study the 2+1d momentum and spatial structure of protons and nuclei. These measurements will provide critical new insights into the QCD structure of nucleons and nuclei in the near term, as well as the high
precision data that will be essential to enable rigorous universality tests when combined with future results from the EIC.

Speaker: elke-caroline Aschenauer (BNL)

STAR.forward.eca.pptx

90 Studies of 3D PDFs with CLAS12

The quark-gluon dynamics manifests itself in a set of non-perturbative functions describing all possible spin-spin and spin-orbit correlations. The Transverse Momentum Dependent parton distributions (TMDs) and Generalized Parton Distributions (GPDs)  carry information not only on the longitudinal but also on the transverse momentum and position of partons, providing rich and direct information on the orbital motion of quarks. Studies of the 3D PDFs are currently driving the upgrades of several existing facilities (JLab, COMPASS and RHIC), and the design and construction of new facilities worldwide (EIC, FAIR, and JPARC).
Although the interest in GPDs and TMD PDFs has grown enormously, we are still in need of fresh theoretical and phenomenological ideas.

The main remaining challenges are extractions of actual 3D PDFs from different spin and azimuthal angle dependent distributions in a reliable and model independent way. In this talk, we present an overview of current status and future measurements of the 3D structure of the nucleon using exclusive and semi-inclusive production of photons and hadrons with the CLAS12 detector at Jefferson Lab.

Speaker: Andrey Kim (University of Connecticut)

DIS2018_AKim.pdf

91 The TMD Program at JLab

As a part of the general nucleon imaging effort, there have been many efforts to access the transverse momentum dependent parton distributions (TMDs) by using the semi-inclusive deep inelastic scatterings (SIDIS) processes. The recently upgraded Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLab) provides golden opportunities to study them in valence quark region. The TMDs describe the three-dimensional, spin-correlated distributions of quarks and gluons in the nucleon in momentum space. The corresponding SIDIS measurements require high intensity and polarization with large kinematic coverage which will be provided by several different detectors. We will highlight some of the SIDIS results from the 6 GeV era and present an overview of the planned JLab TMD program in the 12 GeV era. This work is supported in part by U.S. Department of Energy under contract number DE-FG02-03ER41231.

Speaker: Haiyan Gao (D)

DIS2018-TMD-HGao.pdf

92 Measuring gluon Sivers function at a future Electron-Ion Collider

In this work, we present a systematic study on the feasibility of probing the largely unexplored gluon Sivers function (GSF) based on the open charm production, charged dihadron and dijet method at a future high energy, high luminosity Electron-Ion Collider (EIC). Sivers function describes the anisotropy of parton distributions inside a transversely polarized nucleon in the momentum space and provides us a complete picture of the 2+1D structure of the nucleons. It is proposed that the GSF can be studied through the single spin asymmetry (SSA) measurement in the photongluon fusion channel with electron proton collisions at the EIC. Using a well tuned Monte Carlo model for deep inelastic scatterings, we estimate the possible constraints of the gluon Sivers effect one can draw from the future EIC data. Comparisons of all the possible measurements further illustrate that the dijet method is the most promising way to demonstrate the presence of GSF and pin down its evolution effect.

Speaker: Liang Zheng (China University of Geosciences (Wuhan))

eca.eic.Gluon.Sivers.pptx

16:00 Coffee

WG7: Future of DIS: discussion for document preparation for European Strategy Update for Particle Physics

93 Discussion for European Strategy Update for Particle Physics (ESUPP): Introduction

This panel discussion will be chaired and moderated by Aharon Levy.

For more detail, see https://indico.cern.ch/event/656250/page/13094-discussion-for-a-document-for-european-strategy-update

Speaker: Aharon Levy (Tel Aviv University (IL))

EPPSU-Introduction.pdf

EPPSU-Introduction.pptx

94 The case for EIC

Speaker: Bernd Surrow (Temple University)

bsurrow-eic-case-tuesdsay-dis2018.pdf

95 The case for LHeC

Speaker: Max Klein

caseLHeCmaxklein.pdf

96 The case for VHEep

Speaker: Allen Christopher Caldwell (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

Panel-Caldwell.pdf

97 The case for FCC

Speaker: David d'Enterria (CERN)

dde_FCC_review_dis18.pdf

98 QCD theory addressed in the above facilities

Speaker: Jianwei Qiu (Jefferson Lab)

Qiu-DIS2018-panel-discussion-QCD.pdf

99 Heavy Ion Theory addressed in the above facilities

Speaker: Nestor Armesto Perez (Universidade de Santiago de Compostela (ES))

armesto_DIS2018_170418.pdf

100 Contributions, comments, and questions from audience

More questions and discussions from the audience and remote participants.

Speaker: Aharon Levy (Tel Aviv University (IL))

Wednesday 18 April

WG1-WG6 Joint Session

101 Recent Spin Structure Function Measurements from CLAS at Jefferson Laboratory

The polarized electron accelerator at Jefferson Laboratory (JLab) in Newport News, Virginia, USA yields a robust program for the study of the spin physics of the nucleon. The CLAS detector and longitudinally polarized target in Hall-B at JLab were employed in multiple measurements of spin-structure functions for the proton and neutron in the resonance and DIS regions at beam energies of up to 6 GeV. Recently published results from the EG1 experiment present extensive measurements of the $g_1$ and $g_2$ structure functions for the proton over a wide kinematic range (0.05 $< Q^2 <$ $ 5$ GeV$^2$ and 1.08 $< W < $ 3 GeV). These data, together with data from the related EG4 and EG1-DVCS experiments in Hall-B, help constrain global models of structure functions, virtual photon asymmetries, and parton helicity distributions, and provide more precise values of higher-twist matrix elements in the framework of the Operator Product Expansion.

Speaker: Dr Robert Fersch (Christopher Newport University)

DIS2018talk_Fersch.pdf

102 Recent STAR Results on the Measurement of the Unpolarized and Polarized Light Quark Flavor Structure of W-Boson Production at RHIC at BNL

The STAR experiment at the Relativistic Heavy-Ion Collider at Brookhaven National
Laboratory is carrying out a spin physics program in high-energy polarized proton collisions
to gain a deeper insight into the spin structure and
dynamics of the proton.

The collision of polarized protons at $\sqrt{s}=510\,$GeV opens a new era of spin-flavor
structure measurements from $W^{+}/W^{-}$ boson production through a measurement of the longitudinal single-spin asymmetry, $A_{L}$. In addition, the measurement of the cross-section ratio of $W^{+}/W^{-}$ boson production provides an independent way to probe the ratio of unpolarized $\bar{d}$ and $\bar{u}$ quark distribution functions. $W^{-(+)}$ bosons are produced in $\bar{u}+d\,(\bar{d}+u)$ collisions and can be detected through their leptonic decays, $e^{-}+\bar{\nu}_{e}\;(e^{+}+\nu_{e})$, where only the respective charged lepton is measured. The discrimination of $\bar{u}+d\;(\bar{d}+u)$ quark combinations requires distinguishing between high $p_{T}$ $e^{-(+)}$ through their opposite charge sign, which in turn requires precise tracking information.

The main STAR detector sub-systems used in this measurement are the Time Projection Chamber (TPC) and the Barrel and Endcap Electromagnetic Calorimeters (BEMC, EEMC). The TPC provides tracking inside an axial magnetic field of $0.5\,$T for a pseudorapidity range of $|\eta|<1.3$. The BEMC and EEMC provide full azimuthal coverage for $|\eta|<1$ and $1.09<\eta<2$, respectively. This detector acceptance range measuring scattered $e^{-(+)}$ from $W^{-(+)}$ boson decays in polarized proton collisions at $\sqrt{s}=510\,$GeV allows to probe a kinematic range of roughly $0.05

The status and recent STAR results will be presented on the measurement of $W^{+}/W^{-}$ longitudinal single-spin asymmetry and the cross-section ratio based on data samples taken in 2011, 2012 and 2013. These results are expected to provide important constraints through a global analysis on the understanding of $\bar{d}$ and $\bar{u}$ quark distribution functions.

Speaker: Bernd Surrow (Temple University)

BSurrow-W-Results-STAR-DIS2018-FINAL.pdf

103 W Measurement at PHENIX

The W measurement at RHIC (Relativistic Heavy Ion Collider) provides unique access to the sea quark polarization of the proton. By measuring decay leptons from parity-violating W bosons, which only coupled to left-handed quarks and right-handed antiquarks, a clean, fragmentation free measurement is possible in addition to natural flavor separation. In this talk, we present status and results of single longitudinal spin asymmetry ($A_L$) measurements at PHENIX with data collected in 2011-2013.

Speaker: Dr Chong Kim (UC Riverside)

DIS2018_CKim.pdf

DIS2018_CKim.pptx

104 First extraction of transversity from electron-proton and proton-proton data

We present the first extraction of the transversity distribution in the framework of collinear factorization based on the global analysis of pion-pair production in deep-inelastic scattering off transversely polarized targets and in proton-proton collisions with one transversely polarized proton. The extraction relies on the knowledge of dihadron fragmentation functions, which are taken from the analysis of electron-positron annihilation data. For the first time, the chiral-odd transversity is extracted from a global analysis similar to what is usually done for the chiral-even spin averaged and helicity distributions. The knowledge of transversity is important for detecting possible signals of new physics in high-precision low-energy experiments.

Speaker: Marco Radici

radici.pdf

105 Extraction of Transverse Momentum Distributions from semi-inclusive DIS and Drell-Yan data.

We discuss the first attempt at a "global fit" of unpolarized Transverse Momentum Distributions, using data from semi-inclusive deep inelastic scattering and Drell-Yan processes. We describe the main features of this extraction, compare its outcome with new data, and discuss what further developments are needed.

Speaker: Filippo Delcarro (INFN - National Institute for Nuclear Physics)

FDelcarro_DIS2018.pdf

WG2: Small-x and Diffraction: Session 3

106 Forward energy flow and jet measurements with CMS

We present recent results on forward energy flow and forward jet production measurements in CMS, including measurements with proton-proton collisions at 13 TeV, and proton-lead collisions at 5 TeV.

Speaker: Achim Geiser (Deutsches Elektronen-Synchrotron (DE))

DIS18FSQv3.pdf

107 Forward di-jets in p+A collisions in the ITMD framework

We improve the state-of-the-art description of the disappearance of the away-side peak in forward pA collisions at Relativistic Heavy Ion Collider (RHIC) energies in the framework of the Color Glass Condensate (CGC).
Using the recently proposed improved transverse momentum dependent (ITMD) factorization formula for two-particle production in the back-to-back limit, we derive a parameter-free cross section for the production of two hadrons in dilute-dense collisions, in which the TMD gluon distributions describing the saturated targets are obtained by solving the Balitsky-Kovchegov equation with running coupling corrections.
The resulting cross section provides a good description of the disappearance of the away-side peak in d+Au collisions observed in current RHIC data, although non-CGC effects missing in our calculation prevent us from capturing the overall shape of the di-hadron yield as we move away from $\Delta\phi = \pi$.
We predict the away-side peak of upcoming p+Au data at $\sqrt{𝑠}$ = 200 𝐺𝑒𝑉 to be systematically suppressed by a factor 2 with respect to p+p.
We propose to study the rapidity dependence of the away-side peak suppression as an auxiliary strong proof of gluon saturation in experimental data.

Speaker: Marek Matas

Forward Dijet Production.pdf

108 Multi particle production in proton-nucleus collisions

Using the formalism of the light-cone wave function in perturbative QCD together with the hybrid factorization, we compute the cross-section for three particle production at forward rapidities in proton-nucleus collisions. In this picture, the three produced partons — a quark accompanied by a gluon pair, or two quarks plus one antiquark — are all generated via two successive splittings of a quark from the incoming proton, that was originally collinear with the latter. The three partons are put on-shell by their scattering off the nuclear target, described as Lorentz-contracted “shockwave”. We explicitly compute the three-parton Fock space components of the light-cone wave function of the incoming quark and also the “production” state, which describes the scattering between this dressed quark state and the shockwave for the purposes of computing particle production. This “production” state is also an ingredient for other interesting calculations, like the next-to-leading order correction to the cross-section for the production of a pair of jets.

Speaker: Dr Yair Mulian

dis2018 (1).pdf

109 TMD splitting functions in kT factorization

We calculate the transverse momentum dependent gluon-to-gluon splitting function within kT-factorization, generalizing the framework employed in the calculation of the quark splitting functions in [1205.1759, 1511.08439, 1607.01507] and demonstrate at the same time the consistency of the extended formalism with previous results. While existing versions of kT factorized evolution equations contain already a gluon-to-gluon splitting function i.e. the leading order BFKL kernel or the CCFM kernel, the obtained splitting function has the important property that it reduces both to the leading order BFKL kernel in the high energy limit, to the DGLAP gluon-to-gluon splitting function in the collinear limit as well as to the CCFM kernel in the soft limit. At the same time we demonstrate that this splitting kernel can be obtained from a direct calculation of the QCD Feynman diagrams, based on a combined implementation of the Curci-Furmanski-Petronzio formalism for the calculation of the collinear splitting functions and the framework of high energy factorization.

Speaker: Aleksander Kusina (Institute of Nuclear Physics PAN)

kusina.pdf

110 $\gamma \to \rho^0$ impact factor in QCD: light-cone sum rule calculation

We discuss the \gamma \to \rho^0 impact factor, i.e., the transition amplitude of a photon to a neutral vector meson \rho^0, where the transition is mediated by the two t-channel gluons. The impact factor is a building block in the QCD descriptions of high-energy exclusive processes like $\gamma p \to V p$, and $\gamma\gamma \to V V$, with $V = \rho^0, \omega, \phi$, …. In the framework of QCD factorization, the impact factor is expressed as a convolution of the partonic amplitude, $\gamma g \to q\bar{q} g$, in perturbation theory and the quark-antiquark light-cone distribution amplitudes for the vector meson V. The corresponding factorization formula has been successfully derived for the case of the longitudinal polarization of V. For the transverse polarization of V, however, the corresponding formula is associated with the higher twist (twist-three) contributions and the factorization is known to break down due to infrared divergences which manifest themselves as endpoint singularities arising in the convolution integral. This fact indicates that the impact factor for the transversely polarized vector meson is dominated by the non-factorizable’’ soft contributions. We study the $\gamma \to \rho^0$ impact factor constructing the light-cone QCD sum rules for the corresponding amplitudes, which allow us to estimate the relevant soft contributions in a largely model-independent way, with the use of dispersion relations and quark-hadron duality. We are able to obtain the finite result for the impact factor with the transversely polarized $\rho^0$ meson,$\rho^0_T$’’, as well as for $\rho^0_L$ with the longitudinal polarization. We compare our results with the approach based on the vector meson dominance model associated with the pomeron exchange. As an application, we calculate the cross sections for $\rho^0\rho^0$ production in two-photon collisions, in particular, the cross sections for $\gamma\gamma \to \rho^0_L\rho^0_T$ with the different polarizations in the forward productions of the $\rho^0$ mesons, which may be measured in Belle II experiment.

Speaker: Kazuhiro Tanaka

dis18_tanaka.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 4

111 Measurements of Higgs differential cross-sections at CMS

Results on Higgs differential cross-sections measurements at CMS are reviewed.

Speaker: Giacomo Ortona (Centre National de la Recherche Scientifique (FR))

DIS_Xsec.pdf

112 Measurements and searches of Higgs boson decays to two fermions

Measurements and searches of Higgs boson decays to two third- or two second-generation quarks or leptons are presented using 36 fb-1 of pp collision data collected at 13 TeV.

Speaker: Carlo Schiavi (INFN Genova)

KobeDIS2018-Schiavi-HiggsToFermions.pdf

113 Measurement of cross sections and properties of the Higgs boson in decays to bosons using the ATLAS detector

Measurements of Higgs boson properties and cross sections measured in Higgs boson decays to two photons, two Z bosons, and two W bosons based on pp collision data collected at 13 TeV are presented. In addition, results from the combination of different decay channels are shown.

Speaker: Monica Trovatelli (University of Victoria (CA))

Trovatelli_DIS2018.pdf

114 Standard Model Higgs boson decays into fermions

Observation of Higgs in tautau is reported, together with results from Higgs in bb and mumu decays.

Speaker: Yiwen Wen (Deutsches Elektronen-Synchrotron (DE))

SMHiggsToFermions_DIS2018_YiwenWen.pdf

115 Measurements of the Higgs properties with Run2 data in the bosonic channels

Measurement of the properties of the Higgs boson, especially in the gamma-gamma and ZZ channels, are reported.

Speaker: Elisabetta Gallo (DESY)

ElisabettaGallo_HiggsIntoBosons_CMS_DIS2018.pdf

116 Searches for non-Standard Model decays of the Higgs boson

Theories beyond the Standard Model predict Higgs boson decays at a much enhanced rate compared to the Standard Model, e.g. for decays to Z+photon or a meson and a photon, or decays that do not exist in the Standard Model, such as decays into two light bosons (a). This talk presents recent results based on 36 fb-1 of pp collision data collected at 13 TeV.

Speaker: Xiaohu Sun (University of Alberta (CA))

RareEtNonSMDecayOfHiggs-XiaohuSUN.pdf

WG4: Hadronic and Electroweak Observables: Session 4

117 NNLO predictions for jets and V+jet at the LHC

The production of jets and electroweak gauge bosons in association with a jet, V+jet, constitute two important classes of standard-candle processes at the LHC. Owing to the large event rate and the direct sensitivity to the strong coupling constant and the gluon PDF, they provide an ideal testing ground for our understanding of perturbative QCD in a hadron-collider environment.

I give an overview of the recent theory development for these processes and present phenomenological results and their impact on the interpretation of experimental data.

Speaker: Alexander Yohei Huss (CERN)

ahuss.pdf

118 Threshold and jet radius joint resummation for single-inclusive jet production

We present the first threshold and jet radius jointly resummed cross section for single-inclusive hadronic jet production. We work at next-to-leading logarithmic accuracy and our framework allows for a systematic extension beyond the currently achieved precision. Longstanding numerical issues are overcome by performing the resummation directly in momentum space within Soft Collinear Effective Theory (SCET). We present numerical results for the LHC with and without the joint resummation for different choices of jet radii and observe that the resummation leads to crucial improvements in the description of the data.

Speaker: Felix Ringer (Lawrence Berkeley National Laboratory)

DIS18_FRinger.pdf

119 Differential jet cross sections at the CMS experiment

We present measurements of differential jet cross sections over a wide range in transverse momenta from inclusive jets to multi-jet final states. Studies on the impact that these measurements have on the determination of the strong coupling alpha_s as well as on parton density functions are reported.

Speaker: Anterpreet Kaur (Panjab University (IN))

Anter_DIS_2018.pdf

120 Measurement of the inclusive jet and dijet production with the ATLAS detector

The production of inclusive jets and di-jets at hadron colliders provides a stringent test of perturbative QCD at the highest energies. The process can also be used to probe the gluon density function of the proton. The ATLAS collaboration has measured the inclusive jet production cross section in 20.3 /fb of data collected at a center-of-mass energy of 8TeV and in 3.2 /fb of data collected at a center-of-mass energy of 13TeV. The measurements have been performed differentially in jet rapidity and transverse momentum. The collaboration also presents a measurement of the di-jet cross section at a center-of-mass energy of 13TeV as a function of the di-jet mass and rapidity-difference. The results have been compared with state-of-the-art theory predictions at NLO in pQCD, interfaced with different parton distribution functions. Special focus is drawn on the correlation models of the associated systematic uncertainties and the interpretation of the chi2-values resulting from theory comparisons. The 13 TeV measurements have also been compared with the more recent NNLO predictions.

Speaker: Zdenek Hubacek (Czech Technical University (CZ))

ATL-COM-PHYS-2018-363.pdf

WG7: Future of DIS: Session 3

121 The Science and Status of the US EIC

A high-energy high-luminosity polarized Electron Ion Collider (EIC) was enthusiastically recommended
by the US nuclear science advisory committee (NSAC), as the highest priority new facility
to be built in the US, in its long range planning exercise conducted in 2015. Understanding the role
played by the gluons in binding quarks and gluons in nucleons and nuclei — most of the visible
universe — is the central goal of the EIC. We will summarize the science case for the EIC and
discuss the status of the project on the path to realization.

Speaker: Abhay Deshpande (Stony Brook University)

Abhay-EIC-WG7(1).pdf

122 Di-jets the Path to the (un)polarized Partonic Photon Structure at an EIC

In electron-proton collisions, the incoming electron is coupled directly to a parton of the proton with the exchange of a virtual photon, which has properties close to a real photon when the transfer momentum is small. In QCD, the exchanged physical photon can be approximated as a superposition of the bare photon state (direct process) and the hadronic photon state (resolved process). We discuss how the measurement of di-jets can be utilized to separate these two types of processes. Measuring di-jets in quasi-real photoproduction events, one can effectively access the underlying parton structure of the exchanged photons.
The unpolarized photon PDFs can be extracted with high precision from the di-jet cross section. It will be shown that the polarized PDFs for photons can for the first time be extracted by measuring the double spin asymmetry as function of x_{\gamma}. A tagging method is used to probe the flavor of the parton content experimentally. In addition, we will discuss the effects of the underlying event on these measurements.

Speaker: Mrs Chu Xiaoxuan (Central China Normal University)

DIS_2018_XChu.pdf

123 Coherent vector meson production at an electron ion collider

Exclusive vector meson electroproduction over a broad $Q^2$ range offers a unique opportunity to probe the gluon structure of nuclei to measure nuclear shadowing, and to search for gluon saturation and/or the colored glass condensate at an Electron-Ion Collider. Understanding the kinematic distributions and cross sections for specific processes can impact detector design to maximize their acceptance and strengthen the physics case. We will discuss predictions from a Monte Carlo generator eSTARlight, a tool developed to study production of exclusive vector meson final states. We present final state distributions and production rates for the $\rho$, $\phi$, J/$\psi$, $\psi'$ and the $\Upsilon$ states in $ep$ and $eA$ collisions at the different energies.

Speaker: Michael Lomnitz (Lawrence Berkeley National Lab.)

eSTARlight_DIS_2018_v1.2.pdf

124 A space-time analysis of semi-inclusive deep inelastic scattering on nuclei

A new analysis of published experimental data from the HERMES experiment has been performed. This analysis extracts new information on the space-time properties of color propagation through fitting to a geometric model of the interaction with a realistic nuclear density distribution. Our approach uses a simultaneous fit to the transverse momentum broadening observable and the hadronic multiplicity ratio; the simultaneous fit to two different observables strongly constrains the outcome. We extract the color lifetime, or production time, for the first time. We also extract estimates for the $\hat q$ transport coefficient characterizing the strength of the interaction between the quark and the cold nuclear medium transverse to the direction of the quark. With a three-parameter model we obtain satisfactory fits to the data for the kinematic conditions approximately corresponding to the current fragmentation region. Quark energy loss was also parametrized using a 4-parameter variant of the model, and it was found not to play a significant role in describing the data. We note the important impact of the functional form of the distribution of production lengths on present and future data. Using simple kinematic arguments, we use these results to predict the color lifetime for typical kinematic conditions for 5 GeV measurements at Jefferson lab, for 11 GeV beam at the upgraded Jefferson Lab, and at the energies of the future Electron-Ion Collider.

Speaker: Mr Jorge Andres Lopez Lopez (Federico Santa Maria Technical University (CL))

Lopez_DIS2018.pdf

125 Next-generation neutron structure measurements with spectator tagging at EIC

DIS on the deuteron with detection of a proton in the nuclear fragmentation region ("spectator tagging") represents a unique method for extracting the neutron structure functions and their spin dependence. The measured proton recoil momentum (~ few 100 MeV in the deuteron rest frame) controls the nuclear configuration during the DIS process and allows one to eliminate nuclear binding effects by extrapolating to the on-shell point (free neutron). Such measurements could be performed at a future Electron-Ion Collider (EIC) with suitable forward detectors. We report about recent progress in the theory and simulation of neutron structure measurements with spectator tagging at EIC. This includes (a) development of a theoretical model of nuclear final-state interactions in spectator tagging at intermediate x (~0.1-0.5), caused by the exposure of the spectator nucleon to slow hadrons produced in the DIS process on the active nucleon [arXiv:1706.02244]; (b) calculation of the proton recoil momentum distribution, as determined by initial-state deuteron structure (S and D-waves) and final-state interactions; (c) simulations of recoil momentum measurements and neutron structure extraction at EIC under realistic conditions (beam momentum spread, resolution of forward detectors).

Speaker: Charles Hyde (Old Dominion University)

Tagging_CEH_DIS2018.pptx.pdf

126 Heavy flavor production and large-x nuclear gluons at EIC

Heavy flavor production in DIS (open charm, beauty) provides a direct probe of the gluon density in the target. It can be used to determine the unknown nuclear modifications of the gluon density at large x (EMC effect, antishadowing), which reveal the fundamental QCD substructure of nucleon interactions in the nucleus. We report about a study of open charm production in nuclear DIS at a future EIC. This includes (a) the charm production rates and kinematic distributions at large x; (b) charm reconstruction with exclusive D-meson decays and/or inclusive modes, enabled by the PID and vertex detection capabilities of EIC; (c) the impact of charm data on nuclear gluons; (d) possible extensions to other channels (photoproduction, beauty, jets). We present results of simulations of charm reconstruction obtained with a schematic model of the EIC detector (tracking, vertexing) and outline the performance requirements. The simulation tools developed for this purpose can be used for other EIC studies.

Speaker: Yulia Furletova (Jefferson Lab)

DIS2018-charmJF.pdf

WG5: Physics with Heavy Flavours: Session 4

Excursion instructions

127 Investigating the dominant regions of the phase space associated with $c\bar{c}$ production relevant for the prompt atmospheric neutrino flux

A detailed mapping of the dominant kinematical domains contributing to the prompt atmospheric neutrino flux at high neutrino energies is presented by studying their sensitivity to the cuts on several kinematical variables crucial for charm production in cosmic ray scattering in the atmosphere. This includes the maximal center-of-mass energy for proton-proton scattering, the longitudinal momentum fractions of partons in the projectile (cosmic ray) and target (nucleus of the atmosphere), the Feynman $x_F$ variable, and the transverse momentum of charm quark/antiquark. We find that the production of neutrinos with energies larger than $E_{\nu} > 10^7$  GeV is particularly sensitive to the c.m. energies larger than the ones at the LHC and to the longitudinal momentum fractions in the projectile $10^{-8} < x <1 0^{−5}$. We also analyze the characteristic theoretical uncertainties in the charm production cross section coming from its QCD modeling. The precision data on the prompt atmospheric neutrino flux can efficiently constrain the mechanism of heavy quark production and underlying QCD dynamics in kinematical ranges beyond the reach of the current collider measurements.

Speaker: Victor Gonçalves (Universidade Federal de Pelotas)

talk_HQ_DIS18.pdf

128 Study of radiative decays of the $\Upsilon(1S)$ and of three-body decays of the $J/\psi$

We report on recent studies of quarkonium decays obtained with the data collected by the BaBar experiment at the PEP-II $e^+e^-$ collider.
In particular, we use the entire BaBar dataset to study the reaction $e^+ e^- \to \gamma_{ISR} J/\psi$, with $J/\psi \to \pi^+ \pi^- \pi^0$, $J/\psi \to K^+ K^- \pi^0$, or $J/\psi \to K_S K^\pm \pi^\mp$, and the photon $\gamma_{ISR}$ produced via Initial-State-Radiation. We measure the relative $J/\psi$ branching fractions and perform a Dalitz plot analysis of each $J/\psi$ decay mode using an isobar model and a Veneziano model.
We also present a study of the radiative decays of the $\Upsilon(1S)$ to $\pi^+\pi^-\gamma$ and $K^+K^-\gamma$ final states, performed on the data samples collected at the peak of the $\Upsilon(2S)$ and $\Upsilon(3S)$ resonances. The $\Upsilon(1S)$ is reconstructed from the decay chains $\Upsilon(nS) \to \pi^+\pi^-\Upsilon(1S)$, with $n=2,3$. Branching fractions measurements and spin-parity analysis are reported for the $\Upsilon(1S)$ radiative decays to the several intermediate resonances observed in the $\pi^+\pi^-$ and $K^+K^-$ mass spectra.

Speaker: Patrick Robbe (Université Paris-Saclay (FR))

BaBar_DIS_Upsilon_18Apr2018.pdf

129 Theoretical analysis of the double parton scattering in quarkonium production in proton-proton collision at LHC

The production process of quarkonia in proton-proton (pp) collision is a very good probe of the parton structure of the proton.
Recent experimental data of the production of $J/\psi$+vector boson or quarkonium pairs at the LHC and Tevatron suggest the relevance of double parton scattering (DPS).
In this talk, we will discuss the single parton scattering (SPS) contribution of the $J/\psi+Z$, $J/\psi+W$, and $J/\psi+J/\psi$ productions in hadron collision.
By revisiting the computation of the SPS contribution to $J/\psi+Z$ and $J/\psi+W$ production, we will demonstrate that the ATLAS data in fact show evidence for DPS.

Speaker: Nodoka Yamanaka (Riken)

2018.04.18_yamanaka.pdf

130 Study of Charmed Baryons at Belle

The largest data sample accumulated by the Belle experiment at KEKB asymmetric energy e+e- collider provides an opportunity to perform studies of charmed hadrons. In this presentation, we report on the studies of the decay modes of Lambda_c, Omega_c and spectroscopy of excited Omega_c and Xi_c. The studies presented here use the full data accumulated by the Belle experiment.

Speaker: Mizuki Sumihama (Gifu University)

4_DIS2018_sumihama.pdf

11:00 Coffee

WG1: Structure Functions and Parton Densities: Nuclear PDFs

131 Gluon shadowing and LHC heavy-flavour data

We use for the first time experimental data for the inclusive heavy quark (D0, J/Psi, B->J/Psi and Y(1S) mesons) production in proton-lead collisions at the LHC in order to improve our knowledge of the gluon momentum distribution inside heavy nuclei. We observe that the nuclear effects encoded in both most recent global fits of nuclear parton densities at next-to-leading order (nCTEQ15 and EPPS16) provide a good overall description of the LHC data. We interpret this as a hint that these effects are the dominant ones. In turn, we perform a Bayesian reweighting analysis for each particle data sample which show that each of the existing heavy quark(onium) data clearly point (with a statistical significance ranging from 7 to 11 sigma) to a shadowed gluon distribution at small x in the lead. Our analysis also corroborates the existence of gluon antishadowing. Overall, the inclusion of such heavy-flavour data in a global fit would significantly reduce the uncertainty on the gluon density down to $x \simeq 5*10^{-6}$ while keeping an agreement with the other data of the global fits. Our study accounts for the factorisation scale uncertainties which become the largest for the charm(onium) sector.

Speaker: Aleksander Kusina (Institute of Nuclear Physics PAN)

1_kusina_DIS2018WG1.pdf

132 PDF Flavor Determination and the nCTEQ15 PDFs

We use nCTEQ15 nPDFs with uncertainties to identify measurements which
have a potential impact on nuclear corrections and flavor
differentiation. In particular, recent LHC W/Z vector boson production
data in proton-lead and lead-lead collisions are quite sensitive to
heavier flavors (especially the strange PDF). This complements the
information from neutrino-DIS data. As the proton flavor determination
is dependent on nuclear corrections (from heavy target DIS, for
example), this information can also help improve proton PDFs.

Speaker: Fred Olness (Southern Methodist University)

2_olness_nCTEQ_DIS2018.pdf

133 Impact of CMS 5.02 TeV dijet measurements on gluon PDFs

We discuss the implications of the (preliminary) CMS dijet data from 5.02 TeV pp and pPb collisions for gluon PDFs of the proton and nuclei. The preliminary pp data show a discrepancy with NLO predictions using CT14 and MMHT14 PDFs. We find that this difference cannot be accommodated with the associated scale uncertainties and debate the possible changes needed in the gluon PDFs. A similar discrepancy is found between the CMS pPb data and NLO predictions e.g. with EPPS16 nuclear modifications imposed on CT14 proton PDFs. When a nuclear modification ratio of the pp and pPb data is constructed, the uncertainties in the scale choices and in proton PDFs effectively cancel and a good agreement between the data and EPPS16 is found, except in some bins at backward rapidities corresponding to large x of the nucleus. To assess the impact of these data on EPPS16 nuclear PDFs, we use a non-quadratic extension of the Hessian reweighting method. A significant reduction in EPPS16 uncertainties is obtained with the fit supporting strong nuclear shadowing and valence-like antishadowing for gluons. We also indicate the possible changes needed in the EPPS16 parametrization at large x.

Speaker: Petja Paakkinen (University of Jyväskylä)

Paakkinen_DIS2018.pdf

134 Measurements of Nucleon Structure via Proton-Induced Drell-Yan Process at FNAL SeaQuest

SeaQuest at FNAL is a fixed-target experiment to measure the Drell-Yan process in $p+p$ and $p+A$, using the 120-GeV proton beam and targets of liquid hydrogen, liquid deuterium, carbon, iron and tungsten. During the course of operations, completed in July 2017, it recorded data from $1.4\times 10^{18}$ protons on the various targets.

SeaQuest aims at precisely measuring the flavor asymmetry of light-antiquark distributions ($\bar{d}(x)/\bar{u}(x)$) at large $x$ in the nucleon. It also measures the angular distribution of the Drell-Yan process in $p+p$ and $p+d$ in order to investigate the Lam-Tung relation and further the Boer-Mulders distribution function. It also utilizes the Drell-Yan process in $p+A$ for measuring nuclear effects, including the nuclear dependence of sea quark distributions and the partonic energy loss in cold nuclear matter.

In this talk, the latest updates on the measurements and their impact on understanding of nuclear and hadronic structure will be presented.

Speaker: Dr Kei Nagai (Academia Sinica)

dis2018_knagai.pdf

dis2018_knagai.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 5

135 Search for heavy BSM particles coupling to third generation quarks at CMS

Many models of physics beyond the Standard Model (SM) introduce enhanced couplings to third generation quarks. The predicted signatures at the LHC include single and pair production of vector-like quarks and heavy resonances decaying to third generation quarks. We present results from searches obtained with the full 2016 dataset of proton-proton collisions at 13 TeV. A wide range of final states, from multi-leptonic to entirely hadronic is covered. Jet substructure techniques are employed to identify highly-boosted heavy SM particles in their hadronic decay modes.

Speaker: Douglas Ryan Berry (University of Illinois at Chicago (US))

Berry_HeavyBSMSearches.pdf

136 Dark Matter searches with the ATLAS Detector

As evinced by multiple astrophysical measurements, a large fraction of the matter in the Universe is in the form of a dark, non-baryonic component. If dark matter interacts weakly with the Standard Model it could be produced at the LHC, escaping the detector and thus leaving a signature of large missing transverse momentum. A broad and systematic search program for dark matter production in the LHC collisions recorded by the ATLAS detector is in place: the latest results of these searches will be presented.

Speaker: William Kalderon (Lund University (SE))

DM_searches_ATLAS_DIS2018.pdf

137 Double Higgs searches with Run 2 data at CMS

Results from double Higgs production with the CMS experiment are reviewed.

Speaker: Dr Giacomo Ortona (Centre National de la Recherche Scientifique (FR))

DIS_HH.pdf

138 Search for di-Higgs production

Searches for resonant and non-resonant Higgs boson pair production are performed with LHC data. The searches cover a wide mass range for the resonant case and different decay channels have been explored. No significant deviation from the Standard Model prediction is observed
in data. The 95% conference-level observed and expected limit is set on the cross-section for non-resonant/resonance production.

Speaker: Yaquan Fang (Chinese Academy of Sciences (CN))

HH_analysis_fang_v5.pdf

WG4: Hadronic and Electroweak Observables: Session 5

139 Measurements of the production of jets in association with a W or Z boson with the ATLAS detector

The production of jets in association with vector bosons is an important process to study QCD in a multi-scale environment. The ATLAS collaboration has performed measurements of vector boson+jets cross sections, differential in several kinematic variables, in proton-proton collision data taken at center-of-mass energies of 8TeV and 13TeV. The measurements are compared to state-of-the art theory predictions and can be used to constrain the gluon PDF. In data collected at 8TeV, the collaboration has measured the production of W boson+jets with a large transverse momentum of the leading jet, which enriches the collinear production of the gauge boson and a jet. The measurements are compared to state-of-the-art QCD calculations and Monte Carlo simulations.

Speaker: Nataliia Kondrashova (Shanghai Jiao Tong University (CN))

dis18.pdf

140 Vector Boson production in association with jets at CMS

The production of vector bosons (W, Z, gamma) in association with jets is a stringent test of perturbative QCD and is a background process in searches for new physics. Total and differential cross-section measurements of vector bosons produced in association with jets in proton-proton collisions performed by the CMS collaboration at the LHC are presented. The measurements are compared to the predictions of event generators and theoretical calculations.

Speaker: Anastasia Grebenyuk (Universite Libre de Bruxelles (BE))

DIS2018.pdf

141 alpha_s: Recent developments and future prospects

I will present the current status of the determination of the QCD coupling $\alpha_s$ from the 15 methods where high-precision theoretical calculations and experimental measurements are (or will be) available including, among others: (i) lattice QCD, (ii) $\tau$ hadronic decays, (iii) soft parton-to-hadron fragmentation functions, (iv) proton structure functions, (v) e+e- event shapes and jet rates, (vi) hadronic W and Z boson decays, and (vii) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in e+e- collisions will be summarized.

Speaker: David d'Enterria (CERN)

dde_alphas_review_dis18.pdf

WG5: Physics with Heavy Flavours: Session 5

Excursion instructions

142 Quarkonium production in pp and p-Pb collisions with ALICE at the LHC

Quarkonium production at LHC energies proceeds mainly via gluon fusion on relatively short timescales. The measurement of quarkonium cross sections and kinematical distributions in pp collisions allows one to test available production models. The measurement of such observables in p-Pb collisions provides access to the nuclear modifications of parton distribution functions and to other so-called cold nuclear matter effects. For both colliding systems, the study of quarkonium production as a function of the charged-particle multiplicity provides information on the interplay between the hard and soft sector of QCD.

The inclusive production of charmonium and bottomonium is measured by ALICE down to zero transverse momentum in the forward rapidity region (2.5 < y < 4.0). Charmonium production is also measured down to zero transverse momentum at mid-rapidity (|y| < 0.9), where the non-prompt contribution from beauty-hadron decays can be separated.

The ALICE results on quarkonia in pp and p-Pb collisions will be presented for a wide range of centre-of-mass energies, and compared to theoretical models.

Speaker: Martino Gagliardi (Universita e INFN Torino (IT))

Gagliardi_DIS18_180418.pdf

Gagliardi_DIS18_180418.pdf

Gagliardi_DIS18_180418.pptx

143 Study of Quarkonia and Quarkonium-like States at Belle

The largest data sample accumulated by the Belle experiment at KEKB asymmetric energy e+e- collider provides an opportunity to perform studies of bottomonia. We report on the study of bottomonium production in association with an eta meson in e+ e- annihilations near Y(5S), and the measurement of e+ e^ → chi_bJ phi, chi_bJ omega near Y(6S). We also present the measurement of the decays Y(4S) → eta' Y(1S), Y(2S) → gamma eta_b and Y(1S,2S) → Zc Zc, where Zc is the exotic charmonium-like resonance. Measurements other charmonium-like resonances are also reported.

Speaker: Sen Jia (Beihang University)

DIS2018_Quarkonium_Belle_Sen_Jia.pdf

144 Study of the exotic charmonium-like states from lattice QCD

The charmonium spectroscopy is studied from lattice QCD. An extensive set of excited states as well as the states with exotic quantum numbers are obtained. In this talk, I present and discuss the results in light of experimental observations. In particular, I will discuss the lightest hybrid meson supermultiplet that is identified in our results. Additionally, I will present a preliminary study of the coupled scattering channels $D\bar{D^*}$, $D^*\bar{D^*}$, $J/\Psi \pi$, $\eta_c \rho$, which will shed some light on the structure of the charged charmonium-like states $Z_c(3900)$ and $Z_c(4025)$.

Speaker: Liuming Liu (Institute of Modern Physics, Chinese Academy of Sciences)

talk_v0.pdf

145 Exotic and conventional bottomonium studies at BELLE II

The Belle II experiment, about to start taking data at the KEK laboratory in Japan, is a substantial upgrade of both the Belle detector and the KEKB accelerator.
It aims to collect 50 times more data than existing B-Factory samples beginning in early April 2018.
Belle II is uniquely capable to study the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks.
First discovered by Belle, these now number in the dozens, and represent the emergence of a new category within quantum chromodynamics.
This talk will present the capabilities of Belle II to explore exotic and conventional bottomonium physics.
There will be a particular focus on the physics reach of the first data, where opportunities exist to make an immediate impact in this area.

Speaker: UMBERTO TAMPONI (INFN - National Institute for Nuclear Physics)

8_Tamponi_DIS_2018.pdf

WG6: Spin and 3D structure: Session 3

146 Recent STAR Measurements to Constrain the Polarized Gluon Distribution Function of the Proton

The STAR experiment has been studying the spin structure of the proton, using the unique high-energy polarized proton collider, the Relativistic Heavy Ion Collider (RHIC). The kinematic coverage at STAR allows accessing gluons because quark-gluon and gluon-gluon scatterings dominate particle production at low and medium transverse momentum. The polarized gluon distribution function can be constrained by measuring the longitudinal double-spin asymmetry ($A_{LL}$) of jet production and neutral pions. Global QCD analyses of polarized parton distribution functions, which include the 2009 $A_{LL}$ STAR results for inclusive jet production at $\sqrt{s}=200\,GeV$, provide evidence of a non-zero gluon polarization in the measured range of partonic momentum fraction $x > 0.05$. We present the status of the latest measurements of $A_{LL}$ at STAR, for inclusive jet and dijet production at $\sqrt{s}=510\,GeV$ and $200\,GeV$ collected in 2013 and 2015 respectively, both at mid-rapidity ($|\eta|<0.9$). The large data sample taken during these years will improve the precision of our knowledge about the proton spin structure while the increased center of mass energy allows probing the polarized gluon distribution function at smaller partonic momentum fraction. Furthermore, we present measurements of $A_{LL}$ for neutral pions at forward rapidity ($2.65<\eta<3.9$) collected during 2012 and 2013 that also allow reaching lower partonic momentum fraction. We compare these measurements with the latest global analyses.

Speaker: Amilkar Quintero (Temple University)

AmilkarDIS2018_v4.pdf

147 Inclusive Jet Measurements in Longitudinally Polarized Proton-Proton Collisions at STAR

Jet production in high energy proton-proton ($pp$) collisions is dominated by hard QCD scatterings such as gluon-gluon ($gg$) and quark-gluon ($qg$) scatterings, and therefore an effective tool to probe the internal distribution of gluons in the proton. The STAR Collaboration at Relativistic Heavy Ion Collider (RHIC) is using longitudinally polarized $pp$ collisions at center of mass energies, $\sqrt{s} = $ 200 and 510 GeV, to study the production cross-section and double helicity spin asymmetry, $A_{LL}$, of inclusive jet and di-jet productions. The inclusive jet and di-jet cross-section measurements by STAR at $\sqrt{s} = $ 200 GeV showed the jet cross-section is consistent with next-to-leading-order perturbative QCD calculations after underlying event and hadronic corrections. The STAR 2009 inclusive jet $A_{LL}$ measurement in mid-pseudo-rapidity range, $|\eta| < $ 1.0, at $\sqrt{s} = $ 200 GeV showed the first experimental evidence of an non-zero gluon polarization for Bjorken-$x$, $x > 0.05$. The inclusive jet $A_{LL}$ measurements at $\sqrt{s} = $ 510 GeV allow to explore the gluon polarization at smaller $x \sim 0.02$. In this talk, the inclusive jet $A_{LL}$ and cross-section measurements at $\sqrt{s} =$ 510 GeV, the techniques used in the jet analysis including consideration of underlying event effects, and future perspectives related to jet measurements at STAR will be presented.

Speaker: Zilong Chang (BNL)

DISTalks.pdf

148 Longitudinal Double Spin Asymmetry in Jets in $\surd$s = 510 polarized p+p

The longitudinal double-spin asymmetry $A_{LL}$ in spin-polarized $p+p$ collisions provides insight into the gluon contribution to the proton's spin by accessing the gluon helicity distribution $\Delta$g. Prior RHIC 200 GeV measurements show non-zero asymmetries and hence indicate a nonzero contribution of gluon helicity to the proton spin $\Delta$G for the Bjorken-$x$ range $x > 0.05$ in the recent NLO analyses. The 510 GeV PHENIX $\pi_{0}$ and STAR jet data confirms the non-zero asymmetries and extends constraints on $\Delta$G to lower $x$. A measurement of the jet $A_{LL}$ at $\surd$s = 510 GeV in PHENIX will provide an important cross-check. In this talk, I will detail the jet reconstruction techniques tuned for the PHENIX detector and present the status of the measured jet cross section and $A_{LL}$.

Speaker: Milap Patel (Iowa State University)

DIS_2018.pdf

DIS_2018.pptx

WG7: Future of DIS: Session 4

149 A Summary of the EIC Detector R&D Program

The Electron-Ion Collider (EIC) is the next-generation U.S.-based facility to study Quantum Chromodynamics by probing the dynamics of gluons and sea quarks with comprehensive and systematic measurements of high precision. The experimental program of the EIC is, thus, diverse, covering a broad range of studies from mapping the spatial, momentum, spin, and flavor distributions of gluons and sea quarks in the nucleon to exploring gluon saturation and gluon distributions in nuclei. To carry out this program, the use of different combinations of both beam energy and particle species, wide center-of-mass energy range, measurements of various processes, such as inclusive and semi-inclusive deep-inelastic scattering as well as exclusive elastic and inelastic scattering, and detection of various leptons, mesons, and baryons in the final state, is necessary. The broad experimental scope places challenging and unique requirements on detector capabilities. To name a few, excellent particle identification (PID) over a wide momentum range and full acceptance are a must. The objective of the current generic EIC Detector R&D Program is to develop detector concepts and technologies that are suitable to carry out the EIC scientific program and can operate in the EIC environment. In this talk we will present key aspects of the R&D program, such as calorimetry, PID, and tracking, and discuss the current status of advancing related detector technologies.

Speaker: Yordanka Ilieva (University of South Carolina)

Ilieva_DIS2018.pdf

150 Polarisation measurements for hadron beams in colliders.

In this talk I will discuss the challenges to measure hadron polarization in high collision frequency and luminosity future electron ion colliders.

Speaker: elke-caroline Aschenauer (BNL)

eca.Polarimetry.pptx

151 Geometry tagging for heavy ions at JLEIC

Geometry tagging is an experimental analysis technique for selecting event samples where we can, on a statistical basis, control the geometry of the collision in order to make more incisive physics measurements. This technique has been heavily exploited in heavy ion (AA) collisions at RHIC and the LHC, and played an essential role in the discovery and detailed characterization of the quark gluon plasma, but it has seen only very limited use to date in deep-inelastic scattering. Several physics measurements at the EIC would benefit significantly from the use of this technique, including studies of gluon anti-shadowing, studies of parton propagation, attenuation and hadronization in the nucleus, and ultimately the search for parton saturation. Using geometry tagging, we can create an event sample in eAu collisions with a saturation scale or an average path length equivalent to a minimum bias nucleus of size A=600-800. The JLEIC full-acceptance detector, with full acceptance for forward-going neutrons, protons and nuclear fragments and a high data-taking rate should be ideally suited to such geometry tagging. We improve, tune, and apply existing modeling codes, BeAGLE, Sartre, and GEMC, and detector descriptions to study this physics.

Speaker: V.S. Morozov (Jefferson Lab, Newport News, VA)

9_Morozov_geom_tagging_at_JLEIC_17apr18.pdf

152 Polarized positron beam perspectives for DIS studies

The recent PEPPo (Polarized Electrons for Polarized Positrons) experiment at the
Thomas Jefferson National Accelerator Facility did open an easy and low-cost access
to polarized positron beam through the efficient production of polarized positrons
from the bremsstralhung radiation of a MeV polarized electron beam. The application
of this technique in the context of the upgraded CEBAF (Continuous Electron Beam Accelerator Facility) and the JLEIC (Jefferson Lab Electron Ion Collider) project
allows us to investigate new features of deep inelastic and exclusive scatterings.

This presentation will discuss the current efforts of the Jefferson Lab Positron
Working Group in the process of developping the physics case for a polarized positron beam at JLab 12 GeV and JLEIC.

Speaker: Eric Voutier (CNRS/IN2P3/IPNO - Université Paris-Sud & Paris Saclay)

DIS18-Voutier.pdf

13:00 Lunch

Buffet, 3min walk

WG1-WG5 Joint Session

153 Combination and QCD analysis of beauty and charm production cross section measurements in deep inelastic ep scattering at HERA

Measurements of open beauty and charm production cross sections in deep inelastic ep scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections for beauty and charm production are obtained in the kinematic range of photon virtuality $2.5\le Q^2 \le 2000$ GeV$^2$ and Bjorken scaling variable $3 \times 10^{−5}\le x_{Bj} \le 5 \times 10^{−2}$. The combination method accounts for the correlations of the statistical and systematic uncertainties among the different data sets. The combined data are compared to perturbative QCD predictions and used together with the combined inclusive deep inelastic scattering cross sections from HERA in a next-to-leading order QCD analysis. The running charm and beauty quark masses are determined as $m_c(m_c) = 1.290^{+0.046}_{−0.041}$(exp/fit)${}^{+0.062}_{−0.014}$(model)
${}^{+0.007}_{−0.031}$(param) GeV and $m_b(m_b) = 4.049^{+0.104}_{−0.109}$(exp/fit) ${}^{+0.090}_{ −0.032}$(model)${}^{+0.001}_{-0.031}$(param) GeV.

Speaker: Achim Geiser (Deutsches Elektronen-Synchrotron (DE))

DIS18HERA7.pdf

154 PDF constraints from top-quark pair differential measurements

Constraints on parton distribution functions are presented that are based on differential cross-section measurements of single lepton and dilepton kinematic distributions in dileptonic top quark pair events. The measurements utilize 20.2 fb-1 of sqrt(s) = 8 TeV pp collisions recorded by the ATLAS experiment at the LHC. The sensitivity of the cross-sections to the gluon parton distribution function is explored.

Speaker: Jose Enrique Garcia Navarro (Univ. of Valencia and CSIC (ES))

DIS2018_JEG.pdf

155 Vector Boson production with heavy flavor quarks from CMS

We present measurements of the total and differential cross-section of vector bosons produced with heavy flavor quarks (HF) and the impact of recent V+HF measurements performed by the CMS collaboration on the constraints of PDFs.

Speaker: Bugra Bilin (Universite Libre de Bruxelles (BE))

bbilin_dis2018.pdf

156 Heavy-flavour hadron production at LHCb

The LHCb experiment allows to measure the production and polarisation of charm and beauty hadrons including quarkonia in various collision systems in collider and fixed-target mode. The forward rapidity acceptance in the laboratory frame and the covered Q^2 range test perturbative QCD calculations with their factorisation assumptions and put constraints on parton densities of in unique kinematic regimes. In this talk, recent measurements on inclusive production in pp and pPb collisions in collider mode at different centre-of-mass-energies and fixed-target mode will be presented.

Speaker: Patrick Robbe (Université Paris-Saclay (FR))

LHCb_DIS_HF_18Apr2018.pdf

157 Massive charged-current DIS at NNLO and impact on strange-quark distributions

We present calculation of next-to-next-to-leading order QCD corrections to massive charged-current coefficient functions in deep-inelastic scattering. Especially we focus on the application to charm-quark production in neutrino scattering on fixed target that can be measured via the dimuon final state.

Speaker: Dr Jun Gao (Jiao Tong University, Shanghai)

Gao-Charm-DIS2018.pdf

WG2: Small-x and Diffraction: Session 4

158 rho^0 photoproduction and the Q^2 evolution of the shape of gold nuclei

Coherent photoproduction of vector mesons is sensitive to the shape of the target nucleus, as probed at Q^2 ~ (M_V/2)^2. Previously STAR presented a high-statistics measurement of d\sigma/dt for rho^0 photoproduction in ultra-peripheral Au+Au collisions, and made a two-dimensional Fourier-Bessel (Hanckel) transformation to give the distribution of targets in the nucleus. Here, we study the Q^2 evolution of d\sigma/dt and the target distribution by dividing the rho^0 signal into three different mass bins, to see how d\sigma/dt evolves with Q^2, and see the effect on the target distribution. With increasing Q^2, we expect to see a decrease in multiple interactions, which should emphasize the interior of the nucleus cmpared to measurements at lower Q^2.

Speaker: Spencer Klein (University of California Berkeley (US))

KleinSTARDIS2018.pdf

159 Energy dependence of exclusive J/Psi photoproduction in p-Pb interactions at ALICE

The electromagnetic field of a fast moving lead ion at the LHC is an intense source of quasi-real photons. This makes it possible to study J/Psi exclusive photoproduction off protons in p-Pb collisions at the LHC. This process is sensitive to the gluon content of the target. Measuring the scattering angle of the produced vector meson one can compute the centre-of-mass energy (W) of the photon-proton scattering.

Using Run1 data, ALICE has measured the exclusive J/Psi photoproduction cross section in a wide range of scattering angles. In this contribution, we present for the first time measurements of the cross section using the central-barrel detectors of the ALICE, as well as cross sections for a novel topology where one of the muons from the decay of the J/Psi is detected with the forward-muon spectrometer and the other muon with the central-barrel detectors. This allow us to study the evolution of the cross section with energy in a continuous way in the range 20 GeV < W < 700 GeV. The measurements are compared to the newest models of this process.

Speaker: Jesus Guillermo Contreras Nuno (Czech Technical University (CZ))

DIS18_ALICEpPb_v5.pdf

160 Exclusive measurements with CMS

We present recent results on the exclusive production of the Upsilon and rho mesons with the CMS experiment in proton-lead collisions at 5 TeV. And measurements of dipion production in proton-proton collisions at 5, 7, and 13 TeV.

Speaker: Marta Ruspa (Universita e INFN Torino (IT))

ruspa_dis18.pdf

161 Exclusive vector meson photoproduction at Run 2 LHC energies: Color dipole predictions

In this contribution we present a comprehensive analysis of exclusive vector-meson photoproduction in $pp$, $pPb$ and $PbPb$ collisions at Run 2 LHC energies using the color dipole formalism. The rapidity distributions and total cross sections for the $\rho$, $\phi$, $J/\Psi$ and $\Upsilon$ production are estimated considering the more recent phenomenological models for the dipole-proton scattering amplitude, which are based on the color glass condensate formalism and are able to describe the inclusive and exclusive ep HERA data. Moreover, we also discuss the impact of the modeling of the vector-meson wave functions on the predictions. The current theoretical uncertainty in the color dipole predictions is estimated and a comparison with the experimental results is performed.

Speaker: Victor Gonçalves (Universidade Federal de Pelotas)

Talk_UPHIC_Dis18.pdf

162 Subnuclear fluctuations in vector meson photoproduction: a window to saturation

We present a model of coherent and incoherent photoproduction of vector mesons off proton and off nuclear targets. The computations are perfomed within the color-dipole formalism. The targets are described by a profile, in the impact parameter space, including subnucelon degrees of freedom, so-called hot spots. Their positions change event by event. The key aspect of our model is that the number of hot spots grows with energy.

We show that the measurement of dissociative production off protons and incoherent production off nuclear targets at different energies offers new signatures of saturation. These measurements can be performed with current LHC data. This work is based on results presented in Phys.Lett. B766 (2017) 186-191 and arXiv:1711.01855 (accepted by PRC). We will also present new results from our model.

Speaker: Jesus Guillermo Contreras Nuno (Czech Technical University (CZ))

DIS2018_jgcn_v0.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 6

163 Search for rare and exotic Higgs boson decays with CMS

Recent results on the search for the rare and exotic decays of the Higgs boson H(125) from the CMS experiment will be presented in this talk. The large dataset delivered by LHC and collisions at higher center of mass energy of 13 TeV have significantly improved the search sensitivity for these rare and exotic decays with respect to Run-1.

Speaker: Chia-Ming Kuo (National Central University (TW))

20180418_DIS2018.pdf

164 Searches for supersymmetry in final states with photons at CMS

Final states with isolated photons are expected in models of gauge mediated breaking of supersymmetry, but they can also occur as a result of decays of Higgs bosons produced in the decay chains of supersymmetric particles. Results of searches for strong and electroweak production of supersymmetry in events with one or two isolated photons are presented, based on pp collisions recorded with the CMS experiment at sqrt(s) = 13 TeV. In the case of strong production, the most stringent mass limits obtained by these searches reach 2 TeV.

Speaker: Marton Bartok (University of Debrecen (HU))

DIS2018_SUSY_photons_final.pdf

165 Reconstruction techniques in supersymmetry searches in the ATLAS experiment

Many supersymmetric scenarios feature final states with non-standard final state objects. The production of massive sparticles can lead to the production of boosted top quarks or vector bosons, high-pt b-jets. At the same time, transitions between nearly mass-degenerate sparticles can challenge the standard reconstruction because of the presence of very soft leptons or jets. The talk will review the application of innovative reconstruction techniques to supersymmetry searches in ATLAS.

Speaker: Dr Eirik Gramstad (University of Oslo (NO))

Reconstruction techniques in supersymmetry searches in the ATLAS.pdf

166 Searches for supersymmetry in resonance production, R-parity violating signatures and events with long-lived particles with the ATLAS detector

R-parity violation introduces many viable signatures to the search for supersymmetry at the LHC. Strongly interacting resonances and lightest supersymmetric particles may decay into many leptons or jets with or without missing transverse momentum. Several supersymmetric models also predict massive long-lived supersymmetric particles. Such particles may be detected through abnormal specific energy loss, appearing or disappearing tracks, displaced vertices, long time-of-flight or late calorimetric energy deposits. The talk presents recent results from searches of supersymmetry in resonance production, R-parity violating signatures and events with long-lived particles with the ATLAS detector.

Speaker: Carlos Sandoval Usme (Universidad Antonio Narino (CO))

DIS2018_CarlosSandoval.pdf

167 Searches for electroweak production of supersymmetric gauginos and sleptons with the ATLAS detector

Many supersymmetry models feature gauginos and also sleptons with masses less than a few hundred GeV. These can give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents results from searches for gaugino and slepton pair production in final states with leptons, and were performed with pp collisions at a centre-of-mass energy of 13 TeV.

Speaker: Jeanette Miriam Lorenz (Ludwig Maximilians Universitat (DE))

SUSY_EWK_JLorenz_DIS18.pdf

WG4: Hadronic and Electroweak Observables: Session 6

168 Resummation of transverse observables in hadronic collisions

I will present a method for the computation of logarithmically
enhanced terms at all orders for observables featuring kinematic cancellations
away from the Sudakov limit. I will describe the approach in the context of observables of interest at colliders, and comment on extensions to more general cases.

Speaker: Pier Francesco Monni (CERN)

DIS18_Monni.pdf

169 Bottom quark effects on the ptZ spectrum and the W mass determination

We study lepton-pair production in association with bottom quarks at the LHC,
and present the predictions obtained at next-to-leading order in QCD,
both at fixed order and matched with a QCD parton shower, for several differential distributions.
We discuss the estimate of the theoretical uncertainties
and consider the dependence on the perturbative QCD scales (renormalisation, factorisation and shower),
we compare different parton shower models and matching schemes.
We focus on the inclusive lepton-pair transverse momentum distribution,
and propose a simple procedure to accurately include bottom quark effects,
beyond the standard massless approximation.
We estimate how this alternative formulation may affect the tuning of QCD parton shower parameters
and in turn we extrapolate its impact in the simulation of charged-current Drell-Yan observables
and in the W boson mass determination.

Speaker: Alessandro Vicini (Università degli Studi e INFN Milano (IT))

Vicini-eebb.pdf

170 Electroweak Precision Measurements with the ATLAS Detector

With the high integrated luminosities recorded at the LHC and the very good understanding of the ATLAS detector, it is possible to measure electroweak observables to the highest precision. In this talk, we review the measurement of the W boson mass using data, collected at 7 TeV. Special focus is drawn on a discussion of the modeling uncertainties and the physics potential of the latest low-mu runs, recorded at a center of mass energy of 5 and 13 TeV at the end of 2017. The talk will also review the measurement of the triple differential Drell-Yan cross-section at 8 TeV, which can be used to extract the weak mixing angle. We conclude with a presentation of the tau polarization, measured in Z->tautau using 20.3/fb of proton proton collision data collected at a center of mass energy of 8 TeV.

Speaker: Zhiqing Philippe Zhang (LAL, Orsay (FR))

zhang-1804.pdf

171 Top modelling and tuning in CMS

State-of-the-art theoretical predictions accurate to next-to-leading order QCD interfaced with Pythia8, Herwig, and Sherpa event generators are tested by comparing the unfolded ttbar differential data collected with the CMS detector at 8 and 13 TeV. These predictions are also compared with the underlying event activity distributions in ttbar events using CMS proton-proton data collected at a center of mass energy of 13 TeV. In addition, studies of jet shapes in ttbar events at 13 TeV are presented. Studies to derive and test the new CMS event tune obtained through jet kinematics in ttbar events and global event variables are also described.

Speaker: Markus Seidel (CERN)

top_modeling_mseidel.pdf

WG6: Spin and 3D structure: Session 4

172 Transversity in inclusive DIS and novel TMD sum rules

A new collinear factorization analysis of inclusive DIS scattering with suitable non-perturbative “jet correlators” shows​​ that a ​novel, non perturbative ​spin-flip term associated with the invariant mass of the produced hadrons couples to the target's transversity distribution function. In inclusive cross sections, this provides an hitherto neglected and large contribution to the twist-3 part of the g2 structure function, that can explain the discrepancy between recent calculations and fits of this quantity. It also provides an extension of the Burkhardt-Cottingham sum rule, now featuring an interplay between the g2 and h1 functions that calls for a re-examination of their small-x behavior; likewise it provides an extension of the Efremov-Teryaev-Leader sum rule, suggesting a novel way to measure the tensor charge of the proton. As part of the calculation leading to these results, but interesting in their own right, novel TMD sum rules are derived.

Speaker: Alberto Accardi (Hampton U. and Jefferson Lab)

Accardi - Transversity and novel sum rules.pdf

173 Longitudinal-transverse double-spin asymmetry with a $\cos\phi_S$ modulation in SIDIS

We study the double-spin asymmetry $A^{\cos\phi_S}_{LT}$ in semi-inclusive DIS for charged and neutral pions production by scattering a longitudinal polarized beam off a transversely polarized proton target. Within the collinear framework, in which the transverse momentum of the final state hadron is integrated out, we predict the asymmetries for three pion productions at the kinematics of CLAS12 and future Electron Ion Collider. There are two sources contributed to the corresponding asymmetry, one is from the convolution of the twist-3 distribution function $g_{T}(x)$ and the unpolarized fragmentation function $D_1(z)$, the other is from the coupling of the transversity distribution function $h_1(x)$ and the collinear twist-3 fragmentation function $\tilde{E}(z)$. Our numerical results show that the $\cos\phi_S$ asymmetry of pion production at CLAS12 is sizable, and the fragmentation function $\tilde{E}(z)$ plays an important role in the large-$z$ region. The asymmetries at EIC are much smaller than those at CLAS12 due to the suppression in the large-Q region.

Speaker: Dr Wenjuan Mao (School of Physics and Telecommunication Engineering, Zhoukou Normal University)

DIS2018_wjmao-new.pdf

174 Transverse Spin Transfer of Lambda and Anti-Lambda in Polarized Proton-Proton Collisions at 200 GeV at STAR

The transverse spin transfer from polarized proton to $\Lambda$ and $\bar{\Lambda}$ hyperons is expected to be sensitive to the transversity distribution of the nucleon, and to the transversely polarized fragmentation function. We report the first measurement of the transverse spin transfer of $\Lambda$ and $\bar{\Lambda}$ along the polarization direction of the fragmenting quark, $D_{TT}$, in transversely polarized proton+proton collisions at $\sqrt{s}=200 GeV$ with the STAR experiment at RHIC. The data correspond to an integrated luminosity of 18.4 $pb^{-1}$, which cover a kinematic range of pseudo-rapidity $|\eta|$< 1.2 and hyperon transverse momentum $p_T$ up to 8 GeV/c. The prospect of hyperon polarization measurements in the forward pseudo-rapidity region (2.5<$\eta$<4) in proton+proton collisions in 2021+ will also be discussed, which is based on the STAR forward detector upgrade plan including a forward tracking system and a forward calorimeter system.

Speaker: Qinghua Xu (Shandong University)

QXu_DIS2018_DTT.pdf

175 Production of transversely polarized $\Lambda$ hyperon from unpolarized quark fragmentation in the diquark model

We investigate the spin-dependent (naive) T-odd fragmentation function $D^\perp_{1T}$, which can provide an explanation on the transverse polarization of the $\Lambda^0$ hyperon produced in an unpolarized process. We calculate $D^\perp_{1T}$ for light flavors in the spectator diquark model, with a Gaussian form factor at the hyperon-quark-diquark vertex. We include in the calculation both the scalar diquark and axial-vector diquark spectators. We determine the values of the model parameters by fitting the unpolarized fragmentation function $D^\Lambda_1$ to the DSV parametrization for $D^\Lambda_1$. In addition, we compute the longitudinal polarization fragmentation function $G^\Lambda_1$ and compare it with the known parametrization of $G^\Lambda_1$. We also estimate the transverse polarizations of $\Lambda$ production, in both semi-inclusive deep inelastic scattering and single inclusive $e^+e^-$ annihilation.

Speaker: Mr Yongliang Yang (Southeast University)

DIS2018-yangyl.pdf

WG7: Future of DIS: Session 5

176 Energy frontier DIS at CERN: the LHeC and the FCC-eh, PERLE

Energy-frontier DIS can be realised at CERN through an energy recovery linac that would produce 60 GeV electrons to collide with the HL-LHC or, eventually, with the HE-LHC or the FCC hadron beams. It would deliver lepton-proton/nucleus collisions with center of mass energies in the range 0.8-3.5 TeV per nucleon, and luminosities exceeding $10^{34}$ ($5\times 10^{32}$) cm$^{-2}$s$^{-1}$ in ep (ePb). Such machine would provide a huge physics program, with the highest resolution microscope for hadron structure, rich Higgs, top and precision EW physics, large possibilities for BSM searches, and a unique top-energy nuclear physics facility with eventual access to a new regime of QCD at high partonic densities. All these aspects have strong complementarities with the respective, concurrent pp and AA programs. In this talk we review the LHeC and FCC-eh proposals at CERN, with emphasis on the accelerator and infrastructure aspects. We also review the project of an ERL demonstrator, PERLE, under consideration to be built at LAL Orsay.

Speaker: Gianluigi Arduini (CERN)

DIS_18042018_GA_Indico.pdf

DIS_18042018_GA_Indico.pptx

177 Future of Nuclear PDFs

Parton densities PDFs are most important objects both from a fundamental point of view, for characterising the partonic content of hadrons and nuclei, and for the application of collinear factorisation in hadronic and nuclear collisions. Nuclear PDFs are greatly unknown, compared to those in the proton, due to the scarcity of experimental data. In this talk I will first review the present status of nuclear PDFs. Then I will discuss the perspectives of further determining them in presently existing experiments, particularly in pPb collisions at the LHC. Finally I will examine the possibilities that planned experiments, both hadronic machines - HL-LHC - and electron-nucleus colliders - EIC, LHeC and FCC-eh, offer for constraining nPDFs.

Speaker: Nestor Armesto Perez (Universidade de Santiago de Compostela (ES))

armesto_DIS2018_180418.pdf

178 PDFs and alpha_s Measurements

Prospects for high precision determination of PDFs and alpha_s are presented, including results from HL-LHC, FCC, LHeC and EIC.

Speaker: Claire Gwenlan (University of Oxford (GB))

DIS18-PDFs_alphas_Gwenlan.pdf

179 Small-x physics and diffraction at the LHeC and the FCC-eh

The LHeC and the FCC-eh at CERN are projected machines that will deliver ep (ePb) collisions with center-of-mass energies in the TeV range and luminosities of order $10^{34}$ ($5 \times 10^{32}$) cm$^{−2}$s$^{−1}$. In this talk the possibilities for small-x physics and diffraction will be reviewed, with emphasis on recent results on the extraction of diffractive parton densities.

Speaker: Paul Richard Newman (University of Birmingham (GB))

DIS18.pdf

16:00 Coffee

WG1: Structure Functions and Parton Densities: Tools

180 Recent QCD results from the xFitter project

We present the xFitter project  which provides an open-source software framework for the determination of the proton's  parton distribution functions and for the interpretation of the physics analyses in the context of  Quantum Chromodynamics. The project has been used recently for a number of analyses performed by the LHC collaborations and theory community, which are summarised briefly. The xFitter developer’s team also performed several studies in the last year including estimation of the  impact of heavy quark matching scales, which are presented in more details.

Speaker: Fred Olness (Southern Methodist University)

6_olness_xFitter_dis2018.pdf

181 Progress on fast grid techniques for NNLO with APPLfast-NNLO

The fastNLO and APPLgrid projects provide a fast and flexible way to reproduce the results of perturbative QCD cross section calculations with any input parton distribution functions. The latest developments from these projects
are presented with particular emphasis on the common APPLfast interface to the NNLOJET calculation for general cross section calculations at next-to-next-to-leading order (NNLO). The most recent results on the reproduction of
the NNLO coefficients for different physics processes are presented. A mechanism for the general distribution of grids produced at NLO and NNLO by different groups is also discussed.

Speaker: Claire Gwenlan (University of Oxford (GB))

DIS18-APPLfast-Gwenlan.pdf

182 Bayesian perspective on QCD global analysis

In this talk, we present a dedicated analysis of existing Monte Carlo methods in global QCD analysis. We critically examine the interpretability of uncertainties on extracted quantities, such as parton densities or fragmentation functions against nested sampling and more traditional approaches using Hessian methodology. We discuss how in some cases the inclusion of resampling, partition, and cross-validation of data sets can artificially inflate uncertainties on the fitted distributions.

Speaker: nobuo sato (jlab)

slides.pdf

183 Visualizing sensitivity of hadronic experiments to the nucleon structure

Which hadronic experiments constrain the PDF dependence of the Higgs boson cross section? What constrains the strangeness PDF better: LHC vector boson production, (SI)DIS, or jet production? We present a new technique to quantitatively answer such questions without performing a full PDF fit or PDF reweighting. The technique employs the Hessian method and takes into account the (un)correlated experimental uncertainties and PDF-driven correlations. Using this technique, one easily visualizes the distribution of constraints on PDFs in the (x, Q) plane and can estimate the potential impact of future experiments without performing a fit.

Speaker: Fred Olness

9_olness_pdfSense_dis2018.pdf

184 ePump, the Error PDF Updating Method Package

The LHC is bringing us lots of very precise measurements. The calculation of the corresponding theoretical prediction with the same precision is very time consuming in general. It is then a very challenge work to study the impact on Parton Distribution Functions(PDFs) from the precision measurements efficiently. We propose to boost the procedure by using ePump, the Error PDF Updating Method Package, a set of classes, functions, etc. for analyzing the impact of new data on the PDF predictions and uncertainties, in the Hessian method.

Speaker: Dr Tie-Jiun Hou (Xinjiang University)

DIS2018_ePump_TJHou.pdf

WG2: Small-x and Diffraction: Session 5

185 Status and Prospects of measurements of exclusive and diffractive processes with the ATLAS detector

In the absence of forward proton tagging, exclusive processes can be distinguished in the central part of the ATLAS detector exploiting the large rapidity gap in the central region and the absence of charged particles reconstructed in the inner tracking detector. This strategy has been exploited to study the exclusive production of dilepton pairs in the data taken at centre-of-mass energies of 7 TeV and the exclusive production of W pairs in the 8 TeV data. We also present the latest results on exclusive dimuon production at 13 TeV. Moreover, the ATLAS collaboration has carried out a study of diffractive dijet production. The data distributions are compared with Monte Carlo models and the rapidity gap survival probability has been estimated in the kinematic region with high diffractive contribution. The talk will conclude with prospects of the upcoming physics program with the Atlas Forward Proton detector. Recent results demonstrate its capabilities to distinguish single diffractive events via forward proton tagging.

Speaker: Andrew Geoffrey Foster (University of Birmingham (GB))

DIS18ExclusiveDiffFinal.pdf

186 The CMS-TOTEM Precision Proton Spectrometer and first physics results

The CT-PPS (CMS-TOTEM Precision Proton Spectrometer) detector system consists of silicon tracking stations as well as timing detectors to measure both the position and direction of protons and their time-of-flight with high precision. They are located at around 200 m from the interaction point in the very forward region on both sides of the CMS experiment. CT-PPS is built to study Central Exclusive Production (CEP) in proton-proton collisions at LHC, including photon-photon production of W and Z boson pairs, high-mass diphoton and dilepton production, high-pT jet production, as well as searches for anomalous couplings and new resonances.

The CT-PPS detector has taken data at high luminosity while fully integrated to the CMS data acquisition system. The total data collected correspond to around 55~${\rm fb}^{-1}$. In this presentation the CT-PPS operation, commissioning and performance are discussed.

The measurements of dilepton and diphoton production in photon-photon fusion with CT-PPS are presented. For the first time, exclusive dilepton production at high masses have been observed in the CMS detector while one or two outgoing protons are measured in CT-PPS using around 10~${\rm fb}^{-1}$ of data accumulated in 2016 during high-luminosity LHC operation. These first results show a good understanding, calibration and alignment of the new CT-PPS detectors. Preliminary results concerning the search for high-mass exclusive diphoton production are presented.

Speaker: Enrico Robutti (INFN e Universita Genova (IT))

robutti_DIS2018_CT-PPS.pdf

187 Measurement of the Total Cross-Section and the rho-Parameter at 13 TeV by TOTEM

The TOTEM experiment at the interaction point 5 of the LHC has measured the total, elastic and inelastic proton-proton cross sections in a centre-of-mass energy range from 2.76 to 13 TeV, in dedicated fills with special beam optics.

Most recently, TOTEM has performed the first measurement of the ρ parameter at $\sqrt{s} = 13$ TeV, where rho is the ratio between the real and the imaginary part of the nuclear elastic scattering amplitude at t = 0.
The unprecedented precision of the measurement, combined with the TOTEM total cross-section measurements, led to the exclusion of all the models classified and published by COMPETE. The ρ and σ_tot results obtained by TOTEM are compatible with predictions -- from alternative theoretical models both in the Regge-like framework and in the modern QCD framework -- of a colourless 3-gluon bound state exchange in the t-channel of the proton-proton elastic scattering.

Speaker: Enrico Robutti (INFN e Universita Genova (IT))

robutti_DIS2018_TOTEM.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 7

188 Searches for strong production of supersymmetry at CMS

Results of searches for the production of supersymmetric partners of gluons and quarks are presented. They are based on pp collisions recorded by the CMS experiment at sqrt(s) = 13 TeV. The searches are performed in final states with 0, 1, or more leptons and are either generic, or specifically designed for the production of third-generation squarks. In the most favorable scenarios, mass limits reach up to 2 TeV.

Speaker: Navid K. Rad (Austrian Academy of Sciences (AT))

DIS2018_StrongSUSY_NavidKRad.pdf

189 Inclusive searches for squarks and gluinos with the ATLAS detector

Despite the absence of experimental evidence, weak scale supersymmetry remains one of the best motivated and studied Standard Model extensions. This talk summarises recent ATLAS results on inclusive searches for supersymmetric squarks and gluinos, including third generation squarks produced in the decay of gluinos. The searches involve final states containing jets, missing transverse momentum with and without light leptons, taus or photons, and were performed with pp collisions at a centre-of-mass energy of 13 TeV.

Speaker: Matt LeBlanc (University of Arizona (US))

201804_MLB_DIS.pdf

190 Searches for direct pair production of third generation squarks with the ATLAS detector

Naturalness arguments for weak-scale supersymmetry favour supersymmetric partners of the third generation quarks with masses not too far from those of their Standard Model counterparts. Top or bottom squarks with masses less than or around one TeV can also give rise to direct pair production rates at the LHC that can be observed in the data sample recorded by the ATLAS detector. The talk presents recent ATLAS results from searches for direct stop and sbottom pair production, using the data collected during the LHC Run 2.

Speaker: Jovan Mitrevski (Ludwig Maximilians Universitat (DE))

DIS2018DirectStopSbottom.pdf

191 Searches for additional Higgs bosons in the MSSM

The MSSM predicts the existence of additional neutral and charged Higgs bosons. This presentation will discuss results from recent searches for these particles in several decay channels based on collision data collected at 13 TeV, and their interpretation within the MSSM.

Speaker: Alvaro Lopez Solis (University of Sheffield)

DIS2018_Kobe_18_04_2018.pdf

WG5: Physics with Heavy Flavours: Session 6

Excursion instructions

192 Open heavy flavour production in pp and p-Pb collisions with ALICE

Measurements of heavy-flavour production are a powerful tool to study the properties of the strongly-interacting partonic medium created in ultra-relativistic heavy-ion collisions. The measurements in pp collisions serve as a precision test of perturbative QCD apart from providing the crucial reference for Pb-Pb collisions. Measurements in p-Pb collisions are used to investigate cold nuclear matter effects such as the modification of the parton densities in nuclei with respect to nucleons, kT broadening and energy loss in cold nuclear matter, or a potential existence of collective phenomena. ALICE is well suited to measure heavy-flavour (charm and beauty) production, not only via the full reconstruction of hadronic decays of D-mesons and charm baryons at mid rapidity but also via the measurement of electrons (muons) from semileptonic heavy-flavour hadron decays at mid (forward/backward) rapidity. The aforementioned measurements are performed over a wide transverse-momentum range thanks to the high precision tracking, good vertexing capabilities and excellent particle identification provided by the ALICE detectors. In this contribution, recent results on open heavy-flavour production in pp and p-Pb collision systems will be presented for a wide range of pT and pseudorapidity and for different center-of-mass energies.

Speaker: Prof. Min Jung Kweon (Inha University (KR))

Apr18DIS_MinJungKweon.pdf

193 Global description of bottomonium suppression in proton-nucleus and nucleus-nucleus collisions at LHC energies

Thanks to an improved comover interaction model, we show that we can reach a global and coherent de- scription of bottomonium suppression in both proton-nucleus and nucleus-nucleus collisions as measured by the CMS and ATLAS collaboration at the LHC. The measured relative suppression of the excited bottomonium states as compared to their ground state in proton-nucleus collisions allows us to constrain the scattering cross sections between the bottomonia and comovers also created during the collisions. Our result hints at a similar momentum distribution of these comovers in the environment created by proton-nucleus and nucleus-nucleus collisions. Along the way of our study, we also update our knowledge for the bottomonium feed-down pattern in the kinematical region relevant for such studies. Besides, we improve our knowledge on the modification of the nuclear parton distribution functions in proton-nucleus collisions.

Speaker: Elena Gonzalez Ferreiro (Universidade de Santiago de Compostela (ES))

FerreiroDIS2018.pdf

194 Heavy flavour spectroscopy and exotic states at LHCb

The LHCb experiment is designed to study heavy hadrons produced in proton-proton collisions at the LHC.
Charmed and charmonium hadrons produced in the pp-collision or in b-hadron decays are studied to identify new states, confirming or disproving those recently claimed, and establishing their quantum numbers. The spectroscopy of heavy baryons is also explored with observations of doubly charmed baryons and new excited states in the beauty sector.

Speaker: Liming Zhang (Tsinghua University (CHINA))

DIS2018-Liming.pdf

195 Heavy quark spectroscopy and exotic states in ATLAS

Heavy quark spectroscopy and exotic states are studied with the ATLAS detector, mainly thorough final states containing muon pairs from J/psi decays. The latest results on searches for exotic (tetra- / penta-quark) states in ATLAS are presented.

Speaker: Konstantin Toms (University of New Mexico (US))

DIS2018_ktoms_2.pdf

WG6: Spin and 3D structure: Session 5

196 Study of fragmentation function at Belle

Precision data taken in e+e- annihilation at or near the Υ(4S) by the Belle experiment has been instrumental in the extraction of spin dependent and integrated fragmentation functions. In this talk, we report our measurement on the invariant-mass and fractional-energy dependence of inclusive production of di-hardons. We also report on the production rate of hyperons and charmed baryons, the transverse polarization of lambda hyperons, and other measurements from Belle.

Speaker: Ralf Seidl (RIKEN)

2018_04_18_DIS_Belle_Seidl.pdf

197 Accessing quark helicity in e^+e^- and SIDIS via dihadron correlations.

The correlation between the longitudinal polarization of a fragmenting quark and the transverse momenta of the produced hadrons was predicted over two decades ago. Nevertheless, experimental searches in the electron-positron annihilation process, both through the so-called jet handedness measurement by the SLD collaboration and more recently via the helicity-dependent dihadron fragmentation function (DiFF) by the BELLE collaboration, did not yield a signal. In this talk, we will first explain the zero result at BELLE, and describe new method for accessing the helicity-dependent DiFF in the same experiment. We will also propose another measurement of the same DiFF in semi-inclusive deep inelastic scattering experiments.

Speaker: Hrayr Matevosyan (University of Adelaide)

Hrayr_Matevosyan-DIS-2018_Kobe_Talk_2.pdf

198 Dihadron correlations in polarized quark hadronization.

We present our recent calculations of the complete set of the leading-twist quark-polarization-dependent dihadron fragmentation functions (DiFFs) to pion pairs. The quark-jet framework is used to model the sequential hadronization of a polarized quark into hadrons, where the polarization transfer to the remnant quark in each hadron emission step is calculated using the spin density matrix formalism. Using Monte Carlo (MC) simulations of the hadronization process, we find non vanishing signal for both helicity- and transverse-polarization-dependent DiFFs. A method is developed for extracting the angular moments of these DiFFs, which enter the expressions for the azimuthal asymmetries for an electron-positron annihilation process into two pairs of hadrons from back-to-back jets and the dihadron production in semi-inclusive deep inelastic scattering. Finally, we derive explicit integral expressions for all four DiFFs where only two hadrons are emitted by a quark and use them to validate our MC results. We also utilize these expressions to study the underlying mechanism for generating the dihadron asymmetries in our sequential hadron emission framework, and discover the crucial role played by the Collins effect.

Speaker: Hrayr Matevosyan (Adelaide University)

199 Semi-inclusive Kaon production at low scales

In perturbative QCD, the masses of the hadrons involved in high energy reactions can usually be neglected. In this talk, I will discuss one case in which this ​may​ not ​be ​a good approximation, namely production of Kaons in electron-proton collisions at low (and not so low) beam energies. In particular, I will present a recent proposal to include hadron masses in theoretical calculations, and how these Hadron Mass Corrections can explain a large discrepancy observed in measurements performed at the HERMES and COMPASS experiments. ​I will​ also ​discuss some preliminary spectator model calculations designed, in particular, to test the range of validity of the ​approximations needed in the ​proposed ​factorization scheme

Speaker: Juan Guerrero (Hampton University/Jefferson Lab)

DIS_2018_Juan_Guerrero.pdf

WG7: Future of DIS: Session 6

200 COMPASS facility beyond 2020

COMPASS at CERN, a facility designed to perform research in the hadron partonic structure and hadron spectroscopy, is now planning its future beyond 2020. After a brief summary of achieved results the presentation will focus on the COMPASS programme, planned between CERN accelerator long shutdowns 2 and 3: measurements of SSA using the muon beam on a transversely polarised deuteron target and proton radius measurement in the elastic muon-proton scattering. A hint at the long-term programme, proposed after the shutdown 3, with conventional muon and hadron beams as well as nonconventional, RF separated kaon/antiproton beams will also be given.

Speaker: Barbara Badelek (University of Warsaw (PL))

badelek_dis2018.pdf

201 The future DIS program in Jefferson Lab's Halls A and C

The recently completed 12 GeV upgrade of Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) has established a unique worldwide capability for the precision study of a variety of inclusive, semi-inclusive, and exclusive reactions in deep inelastic electron-nucleon and electron-nucleus scattering. The near-doubling of CEBAF's maximum electron beam energy to 11 GeV (for electron scattering experiments) will enable the mapping of novel multidimensional aspects of nucleon and nuclear structure in the valence region, such as Transverse Momentum Dependent Parton Distributions (TMDs) and Generalized Parton Distributions (GPDs), with unprecedented precision. An exciting program of experiments is planned in experimental Halls A, B, and C, exploiting recent advances in high-luminosity polarized target technology, as well as new and upgraded detection apparatus, to take maximal advantage of the upgraded CEBAF beam. In this talk, I will present an overview of expected results of interest to the DIS community from planned experiments of the 11 GeV era in JLab's Halls A and C.

Speaker: Andrew Puckett (University of Connecticut)

PuckettDIS2018.pdf

202 Future of 3D Imaging at Jefferson Lab

Jefferson Lab recently completed an electron beam energy upgrade from 6 to 11 GeV. New experiments to study the structure of the nucleon have begun collecting data or are under preparation. The presentation will give an overview of the available detectors and targets in the three experimental halls and outline their experimental programs to image the nucleon three-dimensionally.

Speaker: Stephen Bueltmann (Old Dominion University)

DIS2018_Bueltmann.pdf

203 Nuclear medium studies using DIS experiments with CLAS/CLAS12 at JLab, present and future

Jefferson lab's (JLab) CEBAF (now upgraded CEBAF12) accelerator's fixed target experiments give an unique opportunity to study a wide range of phenomena in nuclear medium using Deep Inelastic Scattering (DIS) measurements. Particularly CLAS Eg2 experiment, where different types of nuclei were exposed to electron beam, have provided important information for nuclear hadronization, hadronic and nuclear correlations, hadronic structure functions studies. These studies are fundamental for better understanding of the confinement in the nuclear medium and the essentials of nuclear structure. Apart of showing the results from already existing data, future plans will be discussed also, particularly already approved a new experiment with upgraded CLAS12, and future experiments in EIC (Electron Ion Collider).

Speaker: Prof. Hayk Hakobyan (UTFSM)

Kobe_2018.pdf

Social Events: Conference dinner

Thursday 19 April

WG1: Structure Functions and Parton Densities: Parton distribution functions 2

204 Illuminating the photon content of the proton within a global PDF analysis

Precision phenomenology at the LHC requires accounting for both higher-order QCD and electroweak corrections as well as for photon-initiated subprocesses. Building upon the recent NNPDF3.1 fit, in this work the photon content of the proton is determined within a global analysis supplemented by the LUXqed constraint relating the photon PDF to lepton-proton scattering structure functions: NNPDF3.1luxQED. The uncertainties on the resulting photon PDF are at the level of a few percent, with photons carrying up to 0.5% of the proton's momentum. We study the phenomenological implications of NNPDF3.1luxQED at the LHC for Drell-Yan, vector boson pair, top quark pair, and Higgs plus vector boson production. We find that photon-initiated contributions can be significant for many processes, leading to corrections of up to 20%. Our results represent a state-of-the-art determination of the partonic structure of the proton including its photon component.

Speaker: Nathan Hartland (NIKHEF)

1_DIS2018-QED.pdf

205 The photon in the MMHT PDFs

We describe the inclusion of the photon as an additional component of the proton in the MMHT framework. The input for the photon is based very directly on the recent LUX determination. We describe the similarities and differences above the input scale and the contribution from both leading twist and higher twist contributions, and their uncertainties. We study the impact on the other PDFs and the fit quality, for both the proton and neutron PDFs, and the implications for LHC physics.

Speaker: Mr Ricky Nathvani (University College London )

DIS_2018_Talk (4).pdf

206 Towards the ${\rm N^3LO}$ evolution of parton distributions

We present a status report on calculations for the four-loop splitting
functions in perturbative QCD, which will pave the way to future
determination of ${\rm N^3LO}$ parton distribution functions of hadrons.
In the large-Nc limit, the exact four-loop contribution to the flavour
non-singlet splitting functions has been obtained. For the remaining
large-Nc suppressed terms, we provide approximate expressions that are
sufficient for phenomenological applications. The status of the
calculations in the flavour-singlet sector will be also briefly
discussed.

Speaker: Takahiro Ueda

ueda_dis2018.pdf

207 Impact of low-x resummation on QCD analysis of HERA data

Fits to the final combined HERA deep-inelastic scattering cross-section data within the conventional DGLAP framework of QCD have shown some tension at low x and low Q2. A resolution of this tension incorporating ln(1/x)-resummation terms into the HERAPDF fits is investigated using the xFitter program. The kinematic region where this resummation is important is delineated. Such high-energy resummation not only gives a better description of the data, particularly of the longitudinal structure function FL, it also results in a gluon PDF which is steeply rising at low x for low scales, Q2≃2.5 GeV2, contrary to the fixed-order NLO and NNLO gluon PDF.

Speaker: Alexander Glazov (Deutsches Elektronen-Synchrotron (DE))

xf_dis.pdf

208 Universal fit of parton distributions and fragmentation functions

We report a new QCD global analysis with a simultaneous extraction of polarized and unpolarized parton densities and fragmentation functions from the available polarized and unpolarized DIS, SIDIS and SIA data sets

Speaker: nobuo sato (jlab)

slides.pdf

209 New parton densities with Parton Branching method

We present a determination of parton densities at NLO obtained with the Parton Branching method using HERA precision data. The parton densities are obtained with the standard and angular ordering evolution scales. For integrated pdfs a significant effect is observed.
The transverse momentum dependent (TMD) densities, automatically obtained with the Parton Branching method, are applied to LHC processes, like Drell Yan pt spectrum and high pt dijet correlations.

Speaker: Armando Bermudez Martinez (CMS-DESY)

NewTMDs.pdf

WG2: Small-x and Diffraction: Session 6

210 Recent PHENIX results probing gluon dynamics in proton-proton and highly asymmetric nuclear collisions at $\sqrt{s_{NN}}$ = 200 and 510 GeV

The dynamics of gluons in high energy proton and nuclei interactions remain an elusive process. Gluon interactions can be accessed via both light and heavy flavor hadron production at the PHENIX experiment at RHIC. In particular, via systematically measuring the nuclear modification in light hadron production in p+A and light-ion-A collisions at $\sqrt{s_{NN}} = 200$ GeV, we observed a distinct pattern emerging across large pseudorapidity (-2 -- 2) and transverse momentum ranges (1 -- 20 GeV/c), which can be used to constrain nuclear PDFs and models of parton energy loss in the cold nuclear matter. In addition, the heavy flavor (HF) quarks can be produced in nuclear collisions via various mechanisms that originate from gluons. Recently, the PHENIX collaboration carried out a systematic study of HF production cross sections in p+p collisions at $\sqrt{s}$ = 200 GeV and 510 GeV via the production channels of non-prompt $J/\Psi$s, single and di-muons production at forward rapidities ($1.2

Speaker: Dr Jin Huang (Brookhaven National Lab)

PHENIX_Gluon.pdf

PHENIX_Gluon.pptx

211 Particle production at LHCb

The unique acceptance of the LHCb experiment at the LHC offers the ability to make studies of QCD that are complementary to those made at the other LHC experiments.
A selection of recent results will be presented, including production measurements, inelastic cross-section measurements, and studies of correlations in particle production.

Speaker: Olaf Steinkamp (Universitaet Zuerich (CH))

180419_DISPROD.odp

180419_DISPROD.pdf

180419_DISPROD.pptx

212 Results for Heavy Flavor and Quarkonium production in high multiplicity p+p and p+A collisions in the CGC framework

Heavy quark pair production in minimum bias p+p and p+A collisions has been studied extensively in the CGC framework and compared successfully to both the RHIC and LHC data on $J/\psi$ production [1, 2], $\psi(2S)$ production [3] and $D$-meson production [4]. We first present an update in this framework based on comparisons to the latest LHC and RHIC data on p+p and light-heavy ion collisions. We will then present novel results [5] on extensions of these studies of Heavy Flavor and Quarkonia to rare events; this work, in completion, demonstrates that this framework captures the systematics of both Heavy-Flavor and Quarkonium production as a function of $N_{\rm charge}$ at both RHIC and the LHC. Finally, we will discuss the importance of Sudakov resummations in this framework to describe $\Upsilon$ production [6, 7].

[1] Y. Q. Ma and R. Venugopalan, Phys. Rev. Lett. 113, no. 19, 192301 (2014).
[2] Y. Q. Ma, R. Venugopalan and H. F. Zhang, Phys. Rev. D 92, 071901 (2015).
[3] Y. Q. Ma, R. Venugopalan, K. Watanabe and H. F. Zhang, arXiv:1707.07266 [hep-ph].
[4] H. Fujii and K. Watanabe, Nucl. Phys. A 920, 78 (2013).
[5] Y. Q. Ma, P. Tribedy, R. Venugopalan, and K. Watanabe, in preparation.
[6] K. Watanabe and B. W. Xiao, Phys. Rev. D 92, no. 11, 111502 (2015).
[7] J. W. Qiu and K. Watanabe, arXiv:1710.06928 [hep-ph].

Speaker: Kazuhiro Watanabe (ODU/JLab)

DIS18-KWatanabe.pdf

213 Exploring gluon saturation with photons in high energy hadron-hadron collisions

We report on a recent computation of the NLO inclusive photon cross section using the Color Glass Condensate framework at the RHIC and LHC energies. Our result is appropriate for collisions where a dilute projectile (proton) hits a dense target (a proton or a heavy ion). We will briefly elucidate the main analytic NLO formula obtained in [1], while the main focus of this contribution are the first numerical results of the inclusive isolated photon cross section up to NLO [2] and its comparison to the available experimental data. Our main findings are summarized as:
(i) We demonstrate the kinematic region where the NLO contribution completely dominates over the LO valence quark bremsstrahlung [3].
(ii) We find that our results compare well with the available $p+p \to \gamma+X$ LHC data at 2.76 TeV and 7 TeV.
(iii) We make predictions for the upcoming LHC data at 13 TeV.

[1] S. Benic, K. Fukushima, O. Garcia-Montero and R. Venugopalan, JHEP 1701, 115 (2017).
[2] S. Benic, K. Fukushima, O. Garcia-Montero and R. Venugopalan, in preparation.
[3] F. Gelis, J. Jalilian-Marian, Phys. Rev. D 66, 014021 (2002).

Speaker: Sanjin Benic

benic_dis2018.pdf

214 Bose Enhancement in the dilute-dense limit

The ridge structure in two-particle correlations produced in high multiplicity collisions at the LHC have been examined in the Color Glass Condensate formalism. In this formalism it was found that in the dilute-dilute nucleus limit, corresponding to glasma graphs, the ridge structure was due to the Bose enhancement associated with two-gluon production, with a successful phenomenology developed on this basis. It was an open question whether or not Bose enhancement existed beyond this leading limit. Using the full dilute-dense result for two-gluon correlations we identify the contributions that survive the higher order saturation corrections in the target. We do find a Bose enhanced component of the correlation function when the two produced gluons have either equal transverse momentum or equal and opposite transverse momentum. Bose enhancement, in effect, produces a major contribution to the ridge structure in two-particle correlations.

Speaker: Douglas Wertepny (Universidade de Santiago de Compostela)

wertepny_DIS2018_final.pdf

WG3: Higgs and BSM Physics in Hadron Collisions: Session 8

215 Probing BSM physics with electron-proton colliders

When discussing the future searches for New Physics, electron-positron and proton-proton collider dominate the agenda, the choice being between a clean environment and higher energy. In this talk I will show with two concrete examples (Long-Lived Charged particles in SUSY and Higgs rare decays) how electron-proton colliders combine a clean environment with energies beyond the reach of most planned electron-positron colliders, thus providing an unique opportunity to probe Beyond Standard Model phenomena.

Speaker: José Francisco Zurita (KIT)

Zurita_DIS_2018.pdf

216 Searches for high-mass resonances

Several theories beyond the Standard Model predict the existence of new heavy particles decaying into pairs of gauge bosons. In this presentation the latest ATLAS results on searches for resonances decaying into pairs of W or Z bosons or photons, or into a Z boson and a photon, based on 36 fb-1 of pp collision data collected at 13 TeV will be discussed.

Speaker: Flavia De Almeida Dias (University of Copenhagen (DK))

FDias_DIS2018_HighMassResonances.pdf

217 Searches for additional Higgs bosons at CMS with Run 2 data

Searches for additional scalar bosons with the Run 2 data at CMS are reviewed.

Speaker: Johannes Brandstetter (Austrian Academy of Sciences (AT))

AdditionalHiggs_Brandstetter.pdf

218 Search for heavy resonances in diboson final states at CMS

The large dataset collected so far during Run 2 of the LHC at a centre-of-mass energy of 13 TeV provides a significantly improved sensitivity for discovery of new physics with respect to Run 1. Searches for new resonances in di-boson final states (VV, VH, HH, where V = W, Z) with the CMS detector are presented. The analyses are optimised for high sensitivity over a large range in resonance mass. Jet substructure techniques are used to identify hadronic decays of highly-boosted W, Z, and H bosons.

Speaker: Attilio Santocchia (Universita e INFN, Perugia (IT))

2018.04.19.presentazioneKobe.pdf

219 The SHiP experiment at CERN

SHIP is a new general purpose fixed target facility, whose Technical Proposal has been reviewed by the CERN SPS Committee and by the CERN Research Board. The two boards recommended that the experiment proceeds further to a Comprehensive Design phase in the context of the new CERN Working group "Physics Beyond Colliders", aiming at presenting a CERN strategy for the European Strategy meeting of 2019. In its initial phase, the 400GeV proton beam extracted from the SPS will be dumped on a heavy target with the aim of integrating 2×10^20 pot in 5 years. A dedicated detector, based on a long vacuum tank followed by a spectrometer and particle identification detectors, will allow probing a variety of models with light long-lived exotic particles and masses below O(10) GeV /c2. The main focus will be the physics of the so-called Hidden Portals, i.e. search for Dark Photons, Light scalars and pseudo-scalars, and Heavy Neutrinos. The sensitivity to Heavy Neutrinos will allow for the first time to probe, in the mass range between the kaon and the charm meson mass, a coupling range for which Baryogenesis and active neutrino masses could also be explained. Another dedicated detector will allow the study of neutrino cross-sections and angular distributions. ντ deep inelastic scattering cross sections will be measured with a statistics 1000 times larger than currently available, with the extraction of the F4 and F5 structure functions, never measured so far and allow for new tests of lepton non-universality with sensitivity to BSM physics.

Speaker: Mario Campanelli (University College London (UK))

ShipDIS.pdf

220 search for exotic particle at na62

Searches for heavy neutral lepton (HNL) production in charged kaon decays
using the data collected by the NA62 experiment at CERN are reported. Upper
limits are established on the elements of the extended neutrino mixing
matrix for heavy neutral lepton mass in the range 130-450 MeV, improving on
the results from previous HNL production searches. The status and prospects
of searches for lepton flavour and lepton number violation in kaon decays at
the NA62 experiment is also presented.
The high-intensity setup, trigger system flexibility, and detector performance -- high-frequency tracking of beam particles, redundant PID, ultra-high-efficiency photon vetoes —
make NA62 particularly suitable for searching new-physics effect from different scenarios. Results from a search for invisible dark photons produced from pi0 decays are given.
Fixed target experiments are a particularly useful tool in the search of very weakly coupled particles in the MeV-GeV range,
which are of interest, e.g. as potential Dark Matter mediators. The NA62 experiment at the CERN SPS is currently taking data to measure the ultra-rare
decay K->pi \nu \bar{\nu}. Owing to the high beam-energy and a hermetic detector coverage, NA62 also has the opportunity to directly search for a
plaethora of long-lived beyond-the Standard Model particles, such as Axion-like Particles and Dark Photons. In this talk, we will review the status of this searches and give prospects for future data taking at NA62.

Speaker: Riccardo Lollini (Universita e INFN, Perugia (IT))

DIS 2018 exotics - Lollini.pdf

WG4-WG5 Joint Session

221 Measurement of eta_c(1S), eta_c(2S) and non-resonant eta' pi+ pi- production in two-photon collisions at Belle

We report the measurements of gamma gamma ―> eta_c(1S), eta_c(2S)―>eta' pi+ pi- with eta' decay to gamma rho and eta pi+ pi- using 941 fb-1 of data collected with the Belle detector at the KEKB asymmetric-energy e+ e- collider. First observation of eta_c(2S)―>eta' pi+ pi- with a significance 5.5 \sigma including systematic error is obtained. The products of the two-photon decay width and branching fraction of decays to eta' pi+ pi- are determined for the eta_c(1S) and eta_c(2S), respectively. A new decay mode for the eta_c(1S)―>eta' f0(2080) with f0(2080)―>pi+ pi- is observed with a statistical significance of 20 \sigma. The cross section for gamma gamma ―> eta' pi+ pi- and eta' f2(1270) are measured for the first time.

Speaker: Qingnian Xu (University of Chinese Academy of Sciences (CN))

QingnianXu_DIS2018.pdf

222 Recent QCD-related studies with the BaBar detector

We report some of the most recent results in studying different aspects of QCD with about 500 fb$-1$ of data collected by the BaBar experiment at the $e^+e^-$ $B$-factory PEP-II.
Among these, we present a high precision measurement of the mass difference between the $D^*(2010)^+$ and $D^+$ mesons using the decay chain $D^*(2010)^+ \to D^+ \pi^0$, with $D^+ \to K^- \pi^+ \pi^+$. This result is then combined with a previous BaBar measurement of $m(D^*(2010)^+) - m(D^0)$ to extract the mass difference between the charged and neutral $D$ mesons. We obtain results that are approximately seven times more precise than the present world averages.
We also report on the first evidence for a $B$-meson decay to four baryons, $B^0 \to p \bar{p} p \bar{p}$, which can help to shed light on the experimental discrepancy between the inclusive branching fraction of all $B$ meson decay modes with at least a couple of baryons in the final state, measured by ARGUS to be $(6.8 \pm 0.6)\%$ , and the sum of exclusive baryonic channels, Finally, we present a measurement of the spectral function for the $\tau^-\to K^-K_S\nu_{\tau}$ decay, which can be used to determine the hadronic contribution to the muon $g-2$ due to the vacuum polarization,

Speaker: Laura Zani (INFN - National Institute for Nuclear Physics)

dis18_zani.pdf

223 search for K+ to pi+ nu nu at NA62

K->pinunu is one of the theoretically cleanest meson decay where to look for indirect effects of new physics complementary to LHC searches. The NA62 experiment at CERN SPS is designed to measure the branching ratio of the K+->pi+nunu decay with 10% precision. NA62 took data in 2015-2017; the analysis of a partial data set allows to reach the Standard Model sensitivity. The status of the experiments will be reviewed, and prospects will be presented.

Speaker: Paolo Massarotti (Universita e sezione INFN di Napoli (IT))

DIS2018_KPNN.pdf

224 Study of tau neutrino production property with measuring open-Charms at 400 GeV proton beam dump

The property of tau neutrino is not well known, due to difficulty of its production and detection.
The comparison of the neutrino-nucleon cross-section of tau neutrinos and other neutrino flavours is one of the interesting topics.
The tau neutrino cross-section has been measured by the DONUT experiment, but with a large statistical error of $\sim30\%$ and a systematical uncertainty of $\sim50\%$.
The statistics of detected tau neutrinos will be improved by a planned experiment such as SHiP experiment at CERN in near future.
The DsTau collaboration aims to reduce the systematic uncertainty to $10\%$ by measuring the mother particles(Ds mesons) of tau neutrinos at the beam source.
Ds mesons are generated by proton interactions with the beam dump target, which decay in sequence Ds$\rightarrow$ tau $+\nu_{\tau}$ and tau$\rightarrow\nu_{\tau}+X$.
DsTau will collect 1000 Ds$\rightarrow$ tau associated events in $2 \times 10^{8}$ proton interactions with the tungsten target using the 400 GeV/c proton beam at CERN SPS.
The rate and xf distribution of the Ds production will be measured and the reduction of uncertainty on the tau neutrinos production will be achieved as the result.
Since Ds and tau mass difference is small, the kink angle$(\sim7mrad)$ in the Ds to tau trajectory within a short distance of a few mm decay flight is difficult to detect.
Emulsion Cloud Chambers, ECCs, dedicated structure with tungsten plates and nuclear emulsion plates are used to detect small angle kinks at Ds to tau decays.
Since large number,$10^{5}$ events, of associated charm production will be accumulated and analyzed in ECCs, physics of open-charm could be studied as a byproduct.
In this talk, the DsTau project introduction and results from small scale test exposure in 2016, 2017 will be shown.

Speaker: Osamu Sato (Nagoya University (JP))

DsTau_DIS2018.pdf

DsTau_DIS2018.pptx

WG6: Spin and 3D structure: Session 6

225 Overview of GPD program from Jefferson Lab

Jefferson Laboratory has an extensive program of Deep Virtual Exclusive Scattering (DVES). I will review salient results from the 6 GeV era, and present the status and goals of both Deep Virtual Compton Scattering (DVCS) and Deep Virtual Meson Production (DVMP). A set of DVCS and exclusive $\pi^0$ measurements from 7 to 11 GeV have been completed in Hall A. A first JLab observation of J/$\Psi$ photo-production has been reported by the GlueX collaboration in Hall D. DVCS measurements and exclusive vector meson production at 10.6 GeV on the proton are starting this Spring with CLAS12 (Hall B). DVES experiments on a new longitudinally polarized NH$_3$/ND$_3$ target are anticipated in the next few years. A new PbWO$_4$ calorimeter is under construction for future measurements in Hall C. These data will provide new insights on the spatial distribution of quarks and gluons at large-$x$, as well as higher-twist quark-gluon correlations.

Speaker: Charles Hyde (Old Dominion University)

GPDs-JLab-CEH_online.pdf

226 Nucleon Tomography

Generalized parton distributions embody information on both the longitudinal momentum of the quarks as well as their transverse position and thus allow determining a 3-dimensional image of the nucleon. For transversely polarized quarks and or nucleons, the resulting transverse deformation of these images provides new insight on nucleon spin structure and spin-orbit correlations. Twist-3 GPDs provide additional information on the dependence of transverse forces on the impact parameter.

Speaker: Prof. Matthias Burkardt (New Mexico State University)

227 Accessing generalized TMDs through double Drell-Yan and double $\eta_c$ production processes

Being the "mother distributions" of all types of two-parton correlation functions, generalized TMDs (GTMDs) have garnered a lot of attention. We address the important question of how to access GTMDs in physical processes. Recently, we have shown that quark GTMDs can in principle be probed through the exclusive pion-nucleon double Drell-Yan process, where the focus was on two particular GTMDs only. We now present new results concerning access to the remaining quark GTMDs in the same process. We also extend our study to the nucleon-nucleon double Drell-Yan process which is sensitive to chiral-odd GTMDs. Moreover, we show that GTMDs for gluons can be explored via exclusive double $\eta_c$ production in hadronic collisions.

Speaker: Shohini Bhattacharya (Temple University, Philadelphia)

Shohini_DIS2018.pdf

228 Generalized distribution amplitudes and gravitational form factors for pion

Generalized parton distributions (GPDs) have been investigated in the deeply virtual Compton scattering (DVCS) to solve the proton spin puzzle. On the other hand, the generalized distribution amplitudes (GDAs) can be studied in the two-photon process $\gamma^*\gamma→h \bar{h}$ which is accessible at KEKB. Namely, the GDAs are the s-t crossed quantities of the GPDs. In 2016, the differential cross section of the process $\gamma^*\gamma→ \pi^0\pi^0$ was measured by the Belle collaboration in the $e^+e^-$ collision [1], so that the pion GDAs can be obtained by analyzing the Belle data. Expressing the GDAs with a few parameters, we determined the GDAs by a $χ^2$ analysis [2]. The form factors of the quark energy-momentum tensor are obtained from the determined GDAs. Then, we calculated the mass radius as 0.56-0.69 fm and the mechanical radius as 1.45-1.56 fm for the pion by using the form factors. This is the first study on gravitational form factors and radii of hadrons from actual experimental measurements [2]. The Belle II will start taking data in 2018 by the upgraded SuperKEKB. Therefore, much accurate data are expected for the pion in the near future, and other hadron productions will be measured for the GDAs. The GDA studies are valuable for understanding not only the 3D structure but also gravitational properties of hadrons.

[1] M. Masuda et al. (Belle Collaboration), Phys. Rev. D 93, 032003 (2016).

[2] S. Kumano, Qin-Tao Song and O. V. Teryaev, arXiv:1711.08088, Phys. Rev. D in press.

Speaker: Qin-Tao Song (Sokendai, KEK)

Song-dis.pdf

229 Phenomenology with the PARTONS framework of GPD models built from Light Front Wave Functions

Generalized Parton Distributions (GPDs) encode the correlations between longitudinal momentum and transverse position of partons inside hadrons and can give access to a picture of the nucleon structure in 2+1 dimensions. They have been studied theoretically and experimentally for almost two decades and a new experimental era is starting (at JLab and COMPASS currently, and in the future at an EIC) to extract them.

The difficulty is that only an indirect experimental access is so far possible, through different exclusive channels and various observables. Therefore, one has to take into account the many theoretical constraints to be able to produce accurate models and rely on their phenomenology. Two important constraints are called the polynomiality and positivity properties. We will show how to make use of both of them by first modeling low Fock states light-front wave-functions, which gives a GPD in the DGLAP region by a parton number conserved overlap, and then covariantly extending this GPD to the ERBL region.

This work will be illustrated on a constituent quark-like model for valence GPDs. We will show that this allows to produce a phenomenological output (on DVCS data for instance) from this kind of models, which was impossible before. We will demonstrate the unique versatility of the PARTONS framework to achieve this under various perturbative QCD assumptions.

Speaker: Nabil Chouika (CEA Saclay)

presentation_DIS_2018.pdf

WG7: Future of DIS: Session 7

230 QCD Jets in DIS

We consider lepton-jet correlations in deep inelastic scattering (DIS) as a unique probe of the nucleon/ nuclei tomography. We demonstrate the relevant QCD factorization in terms of transverse momentum dependent quark distributions (TMDs), soft functions and jet functions associated with the final state jet. All relevant large logarithms are resummed to next-to-leading logarithmic (NLL) order. In addition, we consider inclusive jet production and we present numerical results relevant for a future Electron-Ion Collider (EIC).

Speaker: Felix Ringer (Lawrence Berkeley National Laboratory)

DIS18_FRinger.pdf

231 Electroweak physics at FCC-eh and LHeC

The potential of the future electron-proton collider facilities LHeC and FCC-eh for electroweak (EW) physics is studies using simulated neutral-current and charged-current DIS cross section data.
These measurements will allow for high precision determinations of the parameters of the EW theory, such as the weak boson masses and the couplings of the light quarks to the Z boson. The potential for precision measurements of the $\rho$ and $\kappa$ parameters, which are parameters particularly sensitive to additional contributions beyond the Standard Model formalism, are explored.

Speaker: Max Klein

eweakLHeC.pdf

232 TOP Production at the LHeC and FCC-he

In this talk we present an overview of top physics at two possible future electron-proton (ep) colliders at the high energy frontier, the LHeC and the FCC-eh. Selected topics include but are not limited to top structure function, top parton distribution functions, top spin polarization, top electric charge, measurement of Vtb, anomalous ttg, ttZ, tbW, tqg, tqH couplings and CP phase
of ttH coupling.

Direct Measurement of Vtd and Vts through electron proton collisions by Hao Sun:

We perform a study on the direct measurement of Vtd and Vts CKM matrix elements, at the electron proton colliders, through W boson and bottom quark associated production channel as well as W boson and jet associated production channel. The W and bottom(jet) final states can be produced by s-channel single top decay or t-channel top exchange. We find even at the current LHC based ep collider, the channels we are using, already result in very good limits, thus good direct measurement potentials to the Vtd and Vts CKM matrix elements.

Speaker: Dr Hao Sun (Dalian University)

3_DIS2018top_pre3.pdf

233 Higgs physics at the LHeC and the FCC-eh

The LHeC and the FCC-eh at CERN are projected machines that will deliver ep collisions with center-of-mass energies in the TeV range and luminosities of order $10^{34}$ cm$^{−2}$s$^{−1}$. In this talk, new results will be presented on future precision Higgs SM properties in these machines, as well as new prospects for searches for exotic Higgs related phenomena in ep collisions at high energies.

Speaker: Uta Klein (University of Liverpool (GB))

DIS2018_UKlein_Higgs.pdf

234 BSM physics at the LHeC and the FCC-eh

The LHeC and the FCC-eh at CERN are projected machines that will deliver ep collisions with center-of-mass energies in the TeV range and luminosities of order $10^{34}$ cm $^{-2}$s$^{-1}$. In this talk, new results will be presented on prospects for BSM searches in both machines.

Speaker: José Francisco Zurita (KIT)

DIS18_BSM@ep_Zurita-Fischer.pdf

11:00 Coffee

WG1: Structure Functions and Parton Densities: Fragmentation functions

235 An analysis of fragmentation functions of charged hadrons including proton-(anti)proton data from the Tevatron and the LHC

In this contribution I will present a determination of the Fragmentation Functions (FFs) of unidentified charged hadrons at next-to-leading order in quantum chromodynamics based on the NNPDF methodology. The analysis includes cross-section data for single-hadron production in electron-positron annihilation, from a variety of experiments, and in proton-(anti)proton collision from the Tevatron and the LHC. I will discuss the quality of the FFs determined in this analysis with particular emphasis on the impact of the proton-(anti)proton data on the gluon distribution.

Speaker: Valerio Bertone (NIKHEF)

bertone_DIS2018_19_04_2018.pdf

236 Kaon multiplicity of SIDIS on the deutron

We study the kaon multiplicity of semi-inclusive DIS off the deutron target with the updated parton distribution functions and fragmentation functions and compare our result with the HERMES data and COMPASS data. We demonstrated the tension between the HERMES data and COMPASS data and will provide our opinion about this tension. We will make comment about the extarcted values of the strange PDF from HERMES data.

Speaker: Chung Wen Kao (Chung Yuan Christian University, Department of Physics)

DIS2018.pdf

DIS2018.pptx

237 K− over K+ multiplicity ratio for kaons produced in DIS with a large fraction of the virtual-photon energy

The $K^−$ over $K^+$ multiplicity ratio is measured in deep-inelastic scattering, for the first time for kaons carrying a large fraction z of the virtual-photon energy. The data were obtained by the COMPASS collaboration using a 160 GeV muon beam and an isoscalar $^6$LiD target. The regime of deep-inelastic scattering is ensured by requiring $Q^2>1$ (GeV/$c)^2$ for the photon virtuality and $W>5$ GeV/$c^2$ for the invariant mass of the produced hadronic system. Kaons are identified in the momentum range from 12 GeV/$c$ to 40 GeV/$c$, thereby restricting the range in Bjorken-$x$ to $0.01 < x < 0.40$. The $z$-dependence of the multiplicity ratio is studied for $z>0.75$. For very large values of $z$, i.e. $z>0.8$, the results contradict expectations obtained using the formalism of (next-to-)leading order perturbative quantum chromodynamics. This may imply that cross-section factorisation or/and universality of (kaon) fragmentation functions do not hold. Our studies suggest that within this formalism an additional correction may be required, which takes into account the phase space available for hadronisation.

Speaker: Ana Sofia Nunes (LIP-Lisbon)

Nunes_20180420.pdf

238 Hadronization in Semi-Inclusive DIS from CLAS at Jefferson Lab

In this talk I will present preliminary results on π+, π- and π0 multiplicity ratios measured as a function of multiple kinematical variables in semi-inclusive DIS on three nuclei (C, Fe, Pb) normalized to deuterium . The series of measurements were performed at Jefferson Lab with 5.014 GeV electron beam incident on a double-target system in which liquid deuterium and one of the solid targets were exposed simultaneously to the beam. These measurements will be further extended in the approved experiment at 11 GeV. The goal is to provide new insights on parton propagation inside nuclear medium and expand current knowledge on hadronization mechanisms. This topic has been of interest to multiple communities: Drell-Yan measurements at Fermilab, heavy-ion collisions in RHIC and LHC and SIDIS measurements from HERMES and CLAS, all of which contribute different kind of information on short distance processes. The advantages of SIDIS are its well understood nuclear medium and ability to investigate time-dependence of hadronization by embedding it in nuclei of increasing size. It is to be hoped that the studies of cold QCD matter, once matured, can influence the interpretation of what is seen in the hot dense systems (LHC), in addition to their intrinsic interest for QCD.

Speaker: Taisiya Mineeva (Universidad Tecnica Federico Santa Maria)

DIS2018-Mineeva.pdf

WG4: Hadronic and Electroweak Observables: Session 7

WG5: Physics with Heavy Flavours

Excursion instructions

239 First measurements of top quark properties with Run-2 data in CMS

Measurements of top quark properties using data collected by the CMS experiment at 13 TeV are presented. The top quark mass is measured in the lepton+jets channel is consistent with the CMS measurements of Run-1. The top quark mass is also studied as a function of the event kinematical properties. For the first time at the LHC, the width of the top quark is directly probed during Run-2, in what constitutes the most precise direct bound of the top quark width performed to date. Finally, searches for flavor-changing neutral currents involving top quarks are also discussed including tZq, and tHq couplings, in top quark pair and single top production.

Speaker: Kai-Feng Chen (National Taiwan University (TW))

dis-2018.pdf

240 Measurements of the top quark mass using the ATLAS detector at the LHC

The latest measurements of the top quark mass using the ATLAS experiment are presented. A measurement based on a multi-dimensional template fit that can constrain the uncertainties on the energy measurements of jets is presented and combined with measurements using dilepton and all-hadronic events. In addition an analysis of the top quark mass using leptonic kinematic variables is discussed. The measurement uses a novel technique to measure the top quark mass with minimal dependence on hadronic jets. A measurement of the top quark width and the measurements that use precision theoretical QCD calculations for both inclusive ttbar production and ttbar production with an additional jet to extract the top quark mass in the pole-mass scheme are also presented.

Speaker: Dr Michele Pinamonti (INFN e Universita Roma Tor Vergata (IT))

TopMassAtAtlas_Pinamonti (3).pdf

241 State of the art POWHEG generators for Top Mass Measurements at the LHC

We study the theoretical uncertainties in the determination of the top-quark mass using next-to-leading-order (NLO) generators interfaced to parton showers (PS) that have different levels of accuracy. Specifically we consider three generators: one that implements NLO corrections in the production dynamics, one that includes also NLO corrections in top decay in the narrow width approximation, and one that implements NLO corrections for both production and decay including finite-width and interference effects. Our aim is to provide an assessment of the uncertainties of purely theoretical origin, we thus consider simplified top-mass related observables that are broadly related to those effectively used by experiments, eventually modelling experimental resolution effects with simple smearing procedures. Examining these observables with generators of increasing accuracy allows us to assess the theoretical errors due to the use of the less accurate generators. Furthermore, we estimate theoretical uncertainties associated with the variation of scales and with the choice of parton distribution functions. In order to give an indicative assessment of the uncertainties due to the shower and to the modelling of non-perturbative effects, we interface our NLO+PS generators to both Pythia8.2 and Herwig7.1, with various settings, and compare the results.

Speaker: Tomas Jezo (University of Zurich)

TJezo.pdf

WG6: Spin and 3D structure: Session 7

242 Small-x Contributions of the Quark and Gluon Helicity to the Proton Spin

The contribution of the quark and gluon helicity distributions to the proton spin requires integrating these helicity PDFs over the entire range of x. This necessarily involves an extrapolation of the measured PDFs at finite values of x into their small-x asymptotics. As is well-known in the case of the unpolarized quark and gluon distributions, the small-x asymptotics are governed by evolution equations, leading to a determination of the intercept: the exponent of the power-law behavior of the PDFs at small x. In this talk, I will present the derivation and solution of the corresponding small-x evolution equations for the quark and gluon helicity PDFs. Because the transfer of spin to small x is a sub-eikonal effect, the small-x evolution equations for helicity are significantly different from the unpolarized ones. The helicity evolution equations I will present resum double logarithms of 1/x, and they are sensitive to the detailed transverse structure of the polarized quark / gluon splitting kernels. The solution of these equations yields a leading-log evaluation of the quark and gluon helicity intercepts, which predict an enhancement of the helicity PDFs in the small-x tails. Preliminary estimates suggest that the enhancement of the proton spin contribution from polarized quarks may be significant, but is much milder for gluons.

Speaker: Matthew Sievert (Los Alamos National Laboratory)

Sievert_DIS_2018.pdf

243 Nucleon spin structure from lattice QCD

We will present results on the nucleon spin decomposition and the momentum distribution among quarks in the nucleon. Techniques for lattice QCD simulations at the physical pion mass applied for the computation of sea-quark and gluon contributions will be presented. We will discuss several challenges and perspectives for future developments.

Speaker: Kyriakos Hadjiyiannakou (The Cyprus Institute)

talk.pdf

244 Next-to-Leading Order QCD Corrections to Inclusive Heavy-Flavor Production in Polarized Deep-Inelastic Scattering

We provide a first calculation of the complete next-to-leading order QCD corrections for heavy flavor contributions to the inclusive structure function $g_1$ in longitudinally polarized deep-inelastic scattering. The results are derived with largely analytical methods and retain the full dependence on the heavy quark’s mass. We discuss all relevant technical details of the calculation and present numerical results for the heavy quark scaling functions. We perform important crosschecks to verify our results in the known limit of photoproduction and for the unpolarized electroproduction of heavy quarks. We also compare our calculations to the available, partial results in the polarized case, in particular, in the limit of asymptotically large photon virtualities. First steps towards phenomenological applications are taken by providing some estimates for inclusive charm production in polarized deep-inelastic scattering at a future electron-ion collider and studying their sensitivity to the polarized gluon distribution. The residual dependence of heavy quark electroproduction on unphysical factorization and renormalization scales and on the heavy quark mass is investigated.

Speaker: Mr Felix Hekhorn (University of Tübingen)

Hekhorn_DIS2018.pdf

WG7: Future of DIS: Session 8

245 Status of the BELLE II experiment and early physics program

The Belle II experiment is a substantial upgrade of Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+e^-$ collider. The accelerator has successfully completed the first phase of commissioning; collisions will start early April 2018. The design luminosity is $8 \times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than the Belle experiment. This large data set will be accumulated with low backgrounds and high trigger efficiency in a clean $e^+e^－$ environment; it will allow to probe New Physics scales that are well beyond the reach of direct production at the LHC, and will complement the searches through indirect effects that are currently ongoing or planned. This talk will review the detector upgrade, and present the early physics program, centered on bottomonium studies..

Speaker: Takeo Higuchi (KEK)

Belle_DIS.20180419.pptx

246 Physics at the Compact Linear Collider (CLIC)

The Compact Linear Collider (CLIC) is a proposed high-luminosity linear
electron-positron collider operated at energies from the top pair
production threshold up to 3 TeV. With its high luminosity and flexible
collision energy CLIC offers a wide spectrum of possible physics research,
from precision measurement of Standard Model parameters to searches for
new particles and new physics phenomena. At the first stage CLIC will be
operated at 350-380 GeV collision energy. At this stage the emphasis is on
precision top quark physics, e.g. via a threshold scan around 350 GeV, and
on model-independent determination of the Higgs boson couplings by
applying the recoil mass technique to Higgs-strahlung events. At the
higher energy stages (1500 and 3000 GeV) Higgs bosons will be produced in
large numbers via the WW-fusion process. This allows to measure the Higgs
boson properties with high precision and to search for rare Higgs decays.
The sensitivity to anomalous top quark form-factors is also improved at
high collision energies. CLIC operation at 3 TeV will allow to perform
direct and indirect searches for supersymmetry and other phenomena of new
physics models. New particles can be discovered in a model-independent way
almost up to the kinematic limit of 1500 GeV, while indirect evidences can
be sensitive to new physics at the scale of tens of TeVs.

In this talk we present an overview of the CLIC physics potential using
physics benchmark studies. The results are based on the full detector
simulations for signal and background processes.

Speaker: Pawel Sopicki

dis2018_sopicki.pdf

247 Direct Measurement of $\rm V_{td}$ and $\rm V_{ts}$ through electron proton collisions

We perform a study on the direct measurement of $\rm V_{td}$ and $\rm V_{ts}$ CKM matrix elements, at the electron proton colliders, through W boson and bottom quark associated production channel as well as W boson and jet associated production channel. The W and bottom(jet) final states can be produced by s-channel single top decay or t-channel top exchange. We find even at the current LHC based ep collider, the channels we are using, already result in very good limits, thus good direct measurement potentials to the $\rm V_{td}$ and $\rm V_{ts}$ CKM matrix elements.

Speaker: Mr Hao Sun (Dalian University of Technology)

DIS2018top.pdf

DIS2018Vtx.pdf

Social Events: Excursion + lunch box

Friday 20 April

Plenary Session: WG summaries

Convener: Masahiro Kuze (Tokyo Institute of Technology (JP))

248 WG1 summary

Speaker: Valerio Bertone (NIKHEF)

WG1_Summary.pdf

249 WG2 summary

Speaker: Arthur Moraes (CBPF - Brazilian Center for Physics Research (BR))

wg2_ Small-x and Diffraction Summary.pdf

250 WG3 summary

Speakers: Linda Carpenter (UC Irvine), Linda Carpenter (Ohio State University), Maximilian J Swiatlowski (University of Chicago (US))

wg3_DIS18_WG3.pdf

251 WG4 summary

Speakers: Emanuele Re (CERN), Mikko Voutilainen (Helsinki Institute of Physics (FI))

wg4_dis2018_04_20.pdf

11:00 Coffee break

Plenary Session: WG summaries

Convener: Matthew Wing (University College London)

252 WG5 summary

Speaker: Mark Andrew Owen (University of Glasgow (GB))

WG5Summary.pdf

253 WG6 summary

Speaker: Yoshitaka Hatta (Japan/Yukawa Institute)

WG6summary.pdf

254 WG7 summary

Speakers: Christian Schwanenberger (Deutsches Elektronen-Synchrotron (DE)), Yulia Furletova (Jefferson Lab)

DIS_summary_talk_WG7.pdf

13:00 Lunch

Plenary Session: Plenary-5

Convener: Allen Christopher Caldwell (Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut) (D)

255 High-energy DIS studies with nucleons

Speaker: Uta Klein (University of Liverpool (GB))

1_DIS2018_UKlein_nucleon.pdf

256 High-energy DIS studies with nuclei

Speaker: Thomas Ullrich (Yale University (US))

2_Ullrich_DIS_eA.pdf

257 Theoretical perspective for the future experiments on parton densities

Speaker: Shunzo Kumano (KEK)

3_sk-pdf-DIS2018-04.pdf

258 An ep/eA Experiment at the LHC

Speaker: Max Klein

4_LHeCexp.pdf

259 Status of the EIC project

Speaker: Prof. Bernd Surrow (Temple University)

5_BSurrow-EIC-Status-Friday-DIS2018.pdf

16:10 Coffee break

Plenary Session: Closing session

Convener: Fred Olness (Southern Methodist University)

260 Concluding talk

Speaker: Katsuo Tokushuku (High Energy Accelerator Research Organization (JP))

DIS2018-summary.pdf

261 Report from the IAC

Speaker: Aharon Levy (Tel Aviv University (IL))

Report-from-IAC-2018.pdf

262 Report from LOC

Speaker: Yuji Yamazaki (Kobe University (JP))

8-0420p2_Adjourn.pptx