EDS Blois 2019: The 18th Conference on Elastic and Diffractive Scattering



Quy Nhon, Vietnam
Bob Hirosky (University of Virginia (US)) , Christina Mesropian (Rockefeller University (US)) , Chung-I Tan

EDS Blois 2019: The 18th conference on Elastic and Diffractive Scattering
XVth Rencontres du Vietnam, June 23-29, 2019, ICISE, Quy Nhon, Vietnam

We are pleased to announce that the registration and abstract submission is open for EDS Blois, the 18th conference on Elastic and Diffractive scattering.  The conference will be in conjunction with the 15th Rencontres du Vietnam series at the International Center for Interdisciplinary Science and Education (ICISE), Quy Nhon, Vietnam.

The series of International Conferences on Elastic and Diffractive Scattering was founded in 1985 in the picturesque old French town of Blois, famous for its XIV - XVIIth century château, inside of which the first meeting took place. Since then, meetings have been organised every two years in different places of the world: New York (1987), Evanston (1989), Isola d'Elba (1991), Providence (1993), Blois (1995), Seoul (1997), Protvino (1999), Prague (2001), Helsinki (2003), Blois (2005), Hamburg (2007), CERN (2009), Quy Nhon (2011), Saariselkä (2013), Borgo (2015), and Prague (2017).

The conference is expected to cover a broad spectrum of topics, ranging from elastic and diffraction processes in high energy physics to collisions of heavy ions, spin physics, and related topics.  The conference will focus on the most recent experimental and theoretical results, prospects for future measurements, and facilitating discussions between experimentalists and theorists.

Topics to be covered:

  • Elastic Scattering and Total Cross Section
  • Diffraction and Central Exclusive Production
  • Heavy Ions
  • Low-x measurements
  • PDFs and hadronic final states
  • Generalized parton distributions
  • Spin Physics
  • Recent Theoretical Developments
  • Future facilities and measurements


(click image for map)

  • Aleksei Ezhilov
  • Alexander Glazov
  • Amilkar Quintero
  • Andrea Signori
  • Anh Dung Le
  • Antoni Szczurek
  • Bob Hirosky
  • Bogdan Pawlik
  • Carlos Sebastian Contreras Hidalgo
  • Christina Mesropian
  • Chung-I Tan
  • Daisuke Kadoh
  • Gavin Pownall
  • Hans Niederhausen
  • Hongxi Xing
  • Jen-Chieh Peng
  • Jun Gao
  • Justin Andrew Williams
  • Leszek Adamczyk
  • Liuti Simonetta
  • Lucian Harland-Lang
  • Lydia Audrey Beresford
  • Marcia Quaresma
  • Mario Campanelli
  • Mario Deile
  • Marta Luszczak
  • Masanori Hanada
  • Michael Albrow
  • Michael Engelhardt
  • Oliver Suranyi
  • Paul Newman
  • Peter Bussey
  • Peter tsang
  • Rajat Gupta
  • Ramona Vogt
  • Richard Brower
  • Robert Astalos
  • Robert Vertesi
  • Roman Pasechnik
  • Roman Riutin
  • Ruchi Chudasama
  • Salvatore Fazio
  • Tie-Jiun Hou
  • Tomasz Stebel
  • Tuan-Anh Pham
  • Wei Wang
  • Wen-Chen Chang
  • Zilong Chang
    • 7:00 PM
      Welcome Reception Seagull Hotel

      Seagull Hotel

    • Opening: Welcome to EDS 2019
      • 1
        Presentation of guests
      • 2
        J. Tran Thanh Van: Welcome
      • 3
        Nguyen Phi Long, Vice President of the province
      • 4
        Presentation of the EDS Blois series
        Speaker: Christina Mesropian (Rockefeller University (US))
      • 5
        Conference photograph
    • Session 1: Diffraction and Central Exclusive Production I
      Convener: Christina Mesropian (Rockefeller University (US))
      • 6
        Recent results from HERA

        Recent results from the H1 and ZEUS collaborations will be presented. Topics will include cross sections for prompt photon production, J/psi and psi' production and rho and rho' production, a study of collective effects, and a fit to diffractive DIS data.

        Speaker: Dr Peter Bussey (University of Glasgow, UK)
    • 10:20 AM
    • Session 1: Diffraction and Central Exclusive Production II
      Convener: Lucian Harland-Lang (University of Oxford)
      • 7
        Measurements of single diffraction using forward proton tagging at ATLAS

        Inclusive single diffractive dissociation (pp->pX) is studied using data collected by the ATLAS experiment at the LHC. The intact proton is reconstructed and measured in the ALFA forward spectrometer, while charged particles from the dissociative system (X) are reconstructed and measured using the ATLAS inner tracking detector and calorimeters. Differential cross sections are presented as a function of the proton fractional momentum loss, the four-momentum transfer squared, and the size of a rapidity gap measured from the edge of the ATLAS calorimeters. The results are interpreted in the framework of Regge phenomenology. If available, measurements of the charged particle multiplicity in single-diffractive events will also be presented, using protons reconstructed in the AFP detectors.

        Speakers: Leszek Adamczyk (AGH University of Science and Technology (PL)) , Leszek Adamczyk (AGH University of Science and Technology (PL))
      • 8
        Recent CMS and CMS-TOTEM results on diffraction and exclusive production

        Here we present overview of the results on diffractive and exclusive measurements with CMS only and CMS-TOTEM data.

        Speaker: Oliver Suranyi (Eötvös Loránd University)
      • 9
        gamma gamma production of heavy particle pairs in proton-proton collisions

        Photon-induced processes in proton-proton interactions have become
        recently very topical. The large energy at the LHC, when combined with
        relatively large luminosity at run II, allows starting the exploration of such processes.

        We discuss the production of $W^+ W^-$ pairs and $t \bar t$ quark-antiquark pairs in proton-proton collisions induced by two-photon fusion including, for
        a first time, transverse momenta of incoming photons.
        The unintegrated inelastic fluxes (related to proton dissociation) of photons
        are calculated based on modern parametrizations of deep inelastic
        structure functions in a broad range of $x$ and $Q^2$.

        We focus on processes with single and double proton dissociation.
        Highly excited remnant systems hadronize producing particles that can be vetoed in the calorimeter. We calculate the associated effective gap
        survival factors. The gap survival factors depend on the process, the mass
        of the remnant system and collision energy.
        The rapidity gap survival factor due to remnant fragmentation for double
        dissociative (DD) collisions is smaller than that for single
        dissociative (SD) process.
        We observe approximate factorisation: $S_{R,DD} \approx S_{R,SD}^2$
        when imposing rapidity veto. For the $W^+W^-$ final state, the remnant
        fragmentation leads to a taming of the cross section when the rapidity
        gap requirement is imposed. Also for $t \bar t$ quark-antiquark pairs, such a condition reverses the hierarchy observed for the case when such condition is taken into account.

        Our results imply that for the production of such heavy objects
        as $t$ quark and $\bar t$ antiquark the virtuality of the photons
        attached to the dissociative system are very large ($Q^2 <$ 10$^{4}$
        GeV$^2$). A similar effect was observed for the $W^+ W^-$ system.

        1. M. Luszczak, L. Forthomme, W. Schafer, A. Szczurek,
          JHEP 1902 (2019) 100.

        2. L. Forthomme, M. Luszczak, W. Schafer, A. Szczurek,
          Phys.Lett. B789 (2019) 300-307.

        3. M. Luszczak, W. Schafer, A. Szczurek,
          JHEP 1805 (2018) 064.

        4. M. Luszczak, W. Schafer and A. Szczurek,
          Phys. Rev. D93 (2016) 7, 074018.

        5. M. Luszczak, A. Szczurek, Ch. Royon,
          JHEP 1502 (2015) 098.

        Speaker: Marta Luszczak (University of Rzeszow)
      • 10
        Diffractive onium - nucleus scattering and genealogy of partonic evolution

        We present a partonic picture for diffractive onium - nucleus scattering from which the distribution of rapidity gap in a certain kinematic region can be deduced. This picture allows us to draw a parallel between diffractive dissociation and the genealogy of partonic evolution, the latter being essentially similar to a branching - diffusion process. In particular, we show that the rapidity gap distribution corresponds to the distribution of the splitting time of the most recent common ancestor of the partons whose transverse momenta are larger than the nuclear saturation scale, when the scattering process is viewed in the restframe of the nucleus. Numerical calculations are also implemented to support the analytical predictions.

        Speaker: Mr Anh Dung Le (CPhT - Polytechnique)
    • 12:40 PM
    • Session 2: Diffraction and Central Exclusive Production III / Elastic Scattering and Total Cross-Section I
      Convener: Peter John Bussey (University of Glasgow (GB))
      • 11
        Using photon collisions to search for dark matter

        We outline a novel search strategy for scalar leptons and dark matter targeting a key area of phase space favoured by cosmological observations and muon g-2 anomalies. This region is experimentally challenging and currently inaccessible at the LHC. By using the LHC protons to source photon-photon interactions and detecting the intact protons with forward detectors, recently installed by the ATLAS and CMS experiments, we have access to new experimental information. We exploit this information to powerfully discriminate against WW backgrounds and gain sensitivity in this challenging LHC blind spot. This is joint work with Jesse Liu.

        Speaker: Lydia Audrey Beresford (University of Oxford (GB))
      • 12
        Searches for Dark Matter at the LHC in forward proton mode

        We analyze in detail the LHC prospects at the center-of-mass enery of 14 TeV for charged electroweakino searches, decaying to leptons, in compressed supersymmetry scenarios, via exclusive photon-initiated pair production. This provides a potentially increased sensitivity in comparison to inclusive channels, where the background is often overwhelming. We pay particular attention to the challenges that such searches would face in the hostile high pile--up environment of the LHC, giving close consideration to the backgrounds that will be present. The signal we focus on is the exclusive production of same-flavour muon and electron pairs, with missing energy in the final state, and with two outgoing intact protons registered by the dedicated forward proton detectors installed in association with ATLAS and CMS. We present results for slepton masses of 120-300 GeV and slepton-neutralino mass splitting of 10-20 GeV, and find that the relevant backgrounds can be controlled to the level of the expected signal yields. The most significant such backgrounds are due to semi-exclusive lepton pair production at lower masses, with a proton produced in the initial proton dissociation system registering in the forward detectors, and from the coincidence of forward protons produced in pile-up events with an inclusive central event that mimics the signal. We also outline a range of potential methods to further suppress these backgrounds as well as to enlarge the signal yields.

        Speaker: Dr Lucian Harland-Lang (University of Oxford)
      • 13
        Searching for odderon exchange in exclusive reactions with $\phi$ meson

        P. Lebiedowicz, O. Nachtmann and A. Szczurek

        Last year results of the TOTEM collaboration suggest
        that the odderon exchange can be responsible for a disagreement
        of theoretical calculations and the TOTEM data (recent Nicolescu papers)
        for elastic proton-proton scattering. Similar conclusion can be drawn when
        comparing recent $p p$ result for $\sqrt{s}$ = 2.74 TeV with the Tevatron data.

        It is premature to draw definite conclusion.
        Here we present our recent studies for two related proceses
        where the odderon exchange may show up.

        The first one is central exclusive production of pairs of $\phi$
        mesons. Here odderon exchange is not excluded by the WA102
        experimental data for high $\phi \phi$ invariant
        masses. The process is advantegous [1]
        as here odderon does not couple to protons
        (the corresponding coupling constant is probably small).
        Predictions for the LHC will be presented.
        The distribution in $M_{\phi \phi}$ and the rapidity difference
        $Y_{\phi \phi}$ seem well suited to identify odderon exchange.

        Finally we discuss a possibility to search for odderon exchange
        for the $p p \to p p \phi$ reaction \cite{LNS2019_phi}.
        At high energies probably the photon-pomeron fusion is the dominant
        process. The odderon-pomeron fusion is an interesting alternative.
        Adding odderon exchange with parameters adjusted for the $\phi \phi$
        final state improves considerably description of the $p p$ angular
        correlations measured in the past by
        the WA102 collaboration at $\sqrt{s}$ = 29.1 GeV.
        At the low energy we consider also some other subleading processes
        that turned out to be rather small.
        Predictions for the LHC will be presented.

        [1] P. Lebiedowicz, O. Nachtmann and A. Szczurek,
        xArxiv:1901.11490, in print in Phys. Rev. D.

        [2] P. Lebiedowicz, O. Nachtmamm and A. Szczurek,
        a paper in preparation.

        Speaker: Prof. Antoni Szczurek (Institute of Nuclear Physics PAN)
      • 14
        Result for Pomeron and Odderon parameter using IR regulators

        We will present new results for the Pomeron and Odderon Slope, Intercept and Wave functions using Infra-red regulator, in particular the Wilsonian ERG ideas.

        Speaker: Dr Carlos Contreras (Santa Maria University)
      • 15
        PPS results and prospects from CMS/TOTEM

        We will present the first results and the physics prospects from the CMS Precision Proton Spectrometers namely the observation of exclusive dileptons at high mass, and the search for quartic anomalous couplings and axion like particles at high masses at the LHC in the CMS collaboration.

        Speakers: Justin Andrew Williams (The University of Kansas (US)) , CMS Collaboration
    • 4:15 PM
    • Session 2: Free Time at the Center
      • 4:45 PM
    • Session 4: Heavy Ions
      Convener: Christina Mesropian (Rockefeller University (US))
      • 16
        Overview of recent ALICE results

        The existence of a deconfined state of matter (quark-gluon plasma, QGP)
        in heavy-ion collisions have been shown in large experiments in the past
        decades. However, it was the CERN LHC Run-2 data taking period that
        really allowed for precision measurements aimed at the understanding of
        its properties in detail. The excellent particle identification
        capabilities of the ALICE experiment provide us with a unique
        opportunity to study the nature of strongly interacting matter under
        extreme conditions. A selection of recent ALICE results from pp, p-Pb, Pb-Pb and Xe-Xe
        collisions, as well as prospects of the upcoming Run-III phase, will be
        presented in this talk.

        Speaker: Robert Vertesi (Hungarian Academy of Sciences (HU))
      • 17
        Photoproduction in pPb/PbPb collisions

        his talk covers the results on photoproduction in pPb and PbPb collision with CMS experiment

        Speakers: Dr Ruchi Chudasama (Eotvos Lorand University (HU)) , CMS Collaboration
      • 18
        Review of Predictions for Production of Hard Probes in p+Pb Collisions at sqrt s_NN = 5.02 and 8.16 TeV and Comparison With Data

        Predictions have been compiled for the $p+$Pb LHC runs, focusing on production of hard probes in cold nuclear matter [1-3]. These predictions were first made for the $\sqrt{s_{_{NN}}} = 5.02$ TeV $p+$Pb run [1] and were later compared to the available data in Ref.~[2]. A similar set of predictions were published for the 8.16~TeV $p+$Pb run in Ref.~[3].

        In this talk, we review a selection of the predictions at the two energies, comparing them to the available data and with each other to study the quality of the predictions as well as their energy dependence.

        [1] J. Albacete et al., Int. J. Mod. Phys. E 22 (2013) 1330007.

        [2] J. Albacete et al., Int. J. Mod. Phys. E 25 (2016) 1630005.

        [3] J. Albacete et al., Nucl. Phys. A 972 (2018) 18.

        Speaker: Ramona Vogt (LLNL)
    • 10:30 AM
    • Session 3: Elastic Scattering and Total Cross Section II
      Convener: Mario Deile (CERN)
      • 19
        Schwinger based QCD formulation's derivation of elastic pp scattering

        Using previously described functional techniques for some non–perturbative, gauge invariant, renormalized QCD processes, a simplified version of the amplitudes — in which forms akin to Pomerons naturally appear — provides fits to ISR and LHC–TOTEM pp elastic scattering data. Those amplitudes rely on a specific function φ(b) which describes the fluctuations of the transverse position of quarks inside hadrons.

        Speaker: Dr Peter Tsang (Brown University)
      • 20
        Results on Total and Elastic Cross Sections in Proton--Proton Collisions at $\sqrt{s} = 200$ GeV Obtained with the STAR Detector at RHIC.

        Bogdan Pawlik for the STAR Collaboration
        We report the first results on differential, total and elastic cross sections in proton-proton collisions at the Relativistic Heavy Ion Collider (RHIC) at $\sqrt{s}=200$ GeV. The data were obtained with the Roman Pot Detector subsystem of the STAR experiment. The data used for this analysis cover the four-momentum transfer squared ($t$) range $ 0.045 \ge -t \le 0.135$ (GeV/c)$^2$. The Roman Pot system was placed downstream of the STAR detector at vertical distance of about $8\sigma_y$ from the beam and operated during standard data taking.The results include values of the exponential slope parameter (B), elastic cross section ($\sigma_{el}$) and the total cross section ($\sigma_{tot}$) obtained by extrapolation of the elastic differential cross section ($d\sigma/dt$) to the optical point at $-t = 0$ (GeV/c)$^{2}$. The detector setup and analysis procedure are reviewed. All results are compared with the world data.

        Speaker: Bogdan Pawlik (Institute of Nuclear Physics PAS)
      • 21
        Recent Elastic and Total Cross-Section Measurements 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, mostly in dedicated fills with special beam optics.

        Most recently, TOTEM has performed a series of detailed measurements at $\sqrt{s}$ = 13 TeV. The total, elastic and inelastic proton-proton cross-sections were determined using the luminosity-independent method based on the optical theorem.
        Elastic scattering data in the Coulomb-nuclear interference region, at squared four-momentum transfers down to |t| ~ 8 x $10^{-4}$ GeV$^{2}$ allowed the first measurement of the rho 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. This measurement, combined with the TOTEM total cross-section results, led to the exclusion of all the models classified and published by COMPETE. The rho and sigma_tot results obtained by TOTEM are compatible with
        predictions of a colourless 3-gluon bound state exchange in the t-channel of proton-proton elastic scattering, as postulated by alternative theoretical models both in the Regge-like framework and in the modern QCD framework.
        On the large |t| side the elastic differential cross-section measurement was
        pushed to 4 GeV$^{2}$. Thanks to very high statistics, the dip-bump structure
        between 0.4 and 0.8 GeV$^{2}$ was surveyed with unprecedented precision. At
        higher |t|-values up to the end of the observed range no further structure
        is present.
        The presentation will conclude with an outlook on measurements planned for LHC Run 3.

        Speaker: Mario Deile (CERN)
    • 12:30 PM
    • Session 3: Elastic Scattering and Total Cross Section III
      Convener: Mario Deile (CERN)
      • 22
        Pomeron and Odderon: J/psi and eta_c electroproduction

        I will discuss exclusive J/psi and eta_c production in electron-proton collisions, mediated in the lowest order QCD by 2- and 3-gluon exchanges. In the recently developed model, we relate the amplitudes for those processes to the correlators of the quark current in the light-cone wave function of the proton. We obtain new estimates of eta_c cross-section at the energy W~10 GeV.

        Speaker: Tomasz Stebel (Institute of Nuclear Physics PAN)
      • 23
        Size and Shape of Hadrons: From Pion Cloud to Pomeron/Odderon, and AdS/CFT

        Proton-proton differential and total cross sections provide information on the energy dependence of proton shape and size. This will be discussed both from a phenomenological and theoretical perspectives. This will include the role of pion cloud, (e.g., Jenkowsky, Szanyi and Tan, hep-ph:1710.10594), new phenomenology based on AdS/CFT, (e.g., Watanabe, et al., hep-ph:1901.09564), and the non-perturbative theoretical foundation of Pomeron/Odderon, (e.g., Brower, Costa, Djuric, Raben and Tan, hep-th:1409.2730).

        Speaker: Chung-I Tan (Brown University)
      • 24
        Odderon, proton structure and hollowness from the model-independent Levy imaging of elastic hadron-hadron collisions
        Speaker: Roman Pasechnik (Lund university)
    • 3:30 PM
    • Session 4: Free time at Center
    • Session 5: Jet/High pT Final States
      Convener: Bob Hirosky (University of Virginia (US))
      • 25
        Measurements of jet substructure at ATLAS

        Theoretical calculations for jet substructure observables with accuracy beyond leading-logarithm 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 searches for physics beyond the Standard Model. In this talk, we present precision measurements that probe the internal structure of jets using data collected by the ATLAS experiment at √s = 13 TeV. The soft drop mass is measured in dijet events. We also present a measurement of substructure variables in ttbar and inclusive jet events. If available, a measurement of jet substructure observables performed using charged particles is also presented. Each of these measurements are performed with large-radius jets. We also present two measurements that probe jet fragmentation and g -> b bbar splitting. All of the measurements are corrected for detector effects, represented as particle-level distributions and are compared to the predictions of various Monte Carlo event generators. New event generator configurations for the modelling of jet production, derived using ATLAS data will also be presented.

        Speakers: Mario Campanelli (University College London (UK)) , ATLAS Collaboration
      • 26
        Measurement of W and Z boson production at ATLAS

        Precision measurements of the production cross sections of W and Z bosons in proton-proton collisions provide stringent tests of perturbative QCD and yield important information about the parton distribution functions (PDFs) for quarks within the proton. We report measurements of fiducial integrated and differential cross sections for inclusive W+, W- and Z boson production, analysed in the electron and muon decay channels, using data collected at center-of-mass energies of 2.76 and 5.02 TeV. The measurement of the W+ and W- cross sections, in bins of the absolute lepton rapidity, and the associated charge asymmetry are also presented. The study is performed using data collected at √s = 8 TeV. If available, measurements of the transverse momentum distribution of Drell-Yan lepton pairs will be presented, including for low-mass Drell-Yan pairs. The measurements are compared with state-of-the-art QCD cross-section calculations.

        Speaker: Aleksei Ezhilov (NRC Kurchatov Institute PNPI (RU))
      • 27
        New insights on the lepton angular distributions in the Drell-Yan process and Z-boson production at the LHC

        The lepton angular distributions of the Drell-Yan process in fixed-target experiments and the Z-boson production at colliders are investigated by an intuitive geometric approach together with perturbative QCD calculations. We show that the main features of the kinematic dependencies of the lepton angular distributions can be well understood in the geometrical approach. Implications of this approach on the rotational invariance of the angular coefficients, the behavior of the coefficients for Z plus jets events, and the angular distributions of other hard processes will be presented. This talk is based on results presented in the following papers:

        Phys. Lett. B758 (2016) 384;
        Phys. Rev. D 96 (2017) 054020;
        Phys. Lett. B789 (2019) 356;
        Phys. Rev. D 99 (2019) 014032

        Speaker: Prof. Jen-Chieh Peng (University of Illinois at Urbana-Champaign)
    • 9:55 AM
    • Session 5: Topics in Astrophycis and Ultra High Energy Interactions
      Convener: Chung-I Tan
      • 28
        Recent IceCube Measurements Using High Energy Neutrinos

        The IceCube Neutrino Observatory, located at the South Pole, is a
        Cherenkov detector that continuously monitors a cubic kilometer of instrumented glacial ice for neutrino interactions in the sub-TeV to EeV energy range. Its
        primary design goal is the study of powerful astrophysical objects
        that could act as natural particle accelerators and thus as sources of
        (ultra) high energy cosmic rays - in short: to do neutrino astronomy.
        The first steps have been realized. IceCube has discovered a diffuse
        flux of high energy astrophysical neutrinos consistent with being
        extra-galactic in origin. In addition it recently obtained evidence for
        neutrino emission from the direction of the blazar TXS 0506+056 and
        thereby possibly identified a first source of high energy cosmic rays.
        Besides high energy astrophysics, IceCube also contributes to
        fundamental particle physics through the study of neutrino interactions
        at these large energies. In this talk I will present recent IceCube
        results of measurements with high energy neutrinos.

        Speaker: Dr Hans Niederhausen (Technical University of Munich)
      • 29
        Astrophysics in Vietnam
        Speaker: Tuan-Anh Pham (Vietnam National Space Center)
    • 11:40 AM
    • 12:45 PM
    • Session 6: 3D Structure of the Proton I
      Convener: Liuti Simonetta (University of Virginia)
      • 30
        Proton spin in 3D momentum space
        Speaker: Andrea Signori (Argonne National Laboratory)
      • 31
        Overview of COMPASS results on spin

        Nucleon structure has been a major subject of study in the recent decades. Its composition in terms of quarks and gluons and how it depends on the momentum, position and spin has been one of the main fields of research of the COMPASS Collaboration. The COMPASS experiment is in operation at CERN since 2002 and presently approved to continue at least till 2021. During these years several different measurements were performed, among them the measurement of Semi Inclusive Deep Inelastic Scattering using longitudinal and transversely polarised NH3 and LiD targets and a high energy/intensity muon beam and the study of the Drell-Yan reaction using transversely polarised NH3 target and a negative pion beam. These measurements give us access to several parton distribution functions, the best known objects to describe the nucleon structure in momentum space. The main results on spin obtained by the COMPASS Collaboration in the last years will be presented.

        Speaker: Dr Marcia Quaresma (Academia Sinica (TW))
      • 32
        Recent Results of the RHIC Spin Program

        The Relativistic Heavy Ion Collide (RHIC) is the only polarized (both longitudinal and transverse) proton collider in the world, capable of reaching center of mass energies of √s = 200 GeV and 510 GeV. At these energies, the dominating processes are quark-gluon and gluon-gluon scattering, allowing the major RHIC experiments probe partons inside the nucleus. The RHIC spin program has provided a great variety of measurements to study the proton structure, in particular the spin composition. Following the measurements that provided the first evidence of non-zero gluon polarization at x > 0.05, several concurrent measurements of longitudinally polarized proton collisions have been performed to increase precision and reduce the sensitivity down to x ~ 10-3; besides estimating the spin contribution of individual sea quarks to the total proton spin. Measurements of transversity distribution of the nucleon and the transversely polarized fragmentation functions are taken at RHIC, due its versatile capability to change the orientation of the colliding protons polarization. Several measurements with different probes are underway, aiming to test universality, constrain evolution of transverse momentum dependence distributions (TMDs) and extract interference fragmentation functions over a wide kinematic range. An overview of the recent physics results of the RHIC spin program and their impact in model calculations is presented. Additionally plans to extend and/or complement these measurements in the near future are discussed.

        Speaker: Amilkar Quintero (Temple University)
      • 33
        Status and prospects of a future Electron-Ion Collider

        The 2015 U.S. Nuclear Physics Long-Range Plan recommended the realization of an electron-ion collider (EIC) as the next large construction project in the United States. A U.S.-based EIC has also recently been endorsed by the U.S. National Academy of Sciences. In their report released in July 2018 they find the scientific case “compelling, unique, and timely”. With its high luminosity, wide kinematic reach in center-of-mass-energy and high lepton and proton beam polarization, the EIC is an unprecedented opportunity to reach new frontiers in our understanding of the internal dynamic structure of nucleons. This new collider will provide definite answers to the following questions: How are the sea quarks and gluons, and their spins, distributed in space and momentum inside the nucleon? How the nuclear environment modifies these quark and gluon distributions? At what scale the growth in the distribution of gluons saturates? What is the role of the orbital motion of sea quarks and gluons in building up the nucleon spin? This presentation will report on the project’s status and prospects. It will also highlight several key high precision measurements from the planned broad physics program at the electron-ion collider and the expected impact on our current understanding of the partonic structure of nucleons and nuclei.

        Speaker: Salvatore Fazio
    • 10:10 AM
    • Session 6: 3D Structure of the Proton II
      Convener: Mario Campanelli (University College London (UK))
      • 34
        Gluon polarization measurements from longitudinally polarized proton-proton collisions at STAR

        Jets produced in the pseudo-rapidity range, $-1.0 < \eta < 1.0$, from $pp$ collisions at RHIC kinematics are dominated by quark-gluon and gluon-gluon scattering processes. Therefore the longitudinal double-spin asymmetry $A_{LL}$ for jets is an effective channel to explore the longitudinal gluon polarization in the proton. At STAR, jets are reconstructed in full azimuth, from the charged-particle tracks seen by the Time Projection Chamber and electro-magnetic energy deposited in the Barrel and Endcap electro-magnetic calorimeters at both $\sqrt{s} = $ 200 and 510 GeV. Early STAR inclusive jet $A_{LL}$ results at $\sqrt{s} = $ 200 GeV provided the first evidence of the non-zero gluon polarization at $x > $ 0.05. At $\sqrt{s} = $ 510 GeV, the inclusive jet $A_{LL}$ is sensitive to the gluon polarization as low as $x \sim $ 0.015. In this talk, we will discuss recent STAR inclusive jet and di-jet $A_{LL}$ results at $\sqrt{s} = $ 510 GeV and highlight the new techniques designed for this analysis, for example the underlying event correction to the jet transverse energy and its effect on the jet $A_{LL}$. Di-jet $A_{LL}$ results are shown for four topologies in regions of pseudo-rapidity, effectively scanning the $x$-dependence of the gluon polarization.

        Speakers: Dr Zilong Chang (Brookhaven National Laboratory) , Dr Zilong Chang
      • 35
        Quark transverse dynamics in hadrons from Lattice QCD

        An ongoing program of evaluating transverse momentum-dependent (TMD)
        observables in hadrons within Lattice QCD is reviewed, summarizing
        recent progress with respect to several challenges faced by such
        calculations. These lattice calculations are based on a definition of
        TMDs through hadronic matrix elements of quark bilocal operators,
        including an appropriate gauge connection between the quarks.
        Results presented include data on the Sivers and Boer-Mulders effects,
        exhibiting the decisive role of the gauge connection in encoding
        information about the struck quark in a deep inelastic scattering
        process. Generalizing these TMD calculations by connecting them with
        information about quark transverse position in the hadron allows one
        to access quark orbital angular momentum and provide a new perspective
        on the proton spin puzzle - the question of how the proton's spin
        arises from the spins and orbital angular momenta of its constituents.

        Speaker: Michael Engelhardt
      • 36
        Generalized Parton Distributions and the Center for Nuclear Femtography

        I will review the theory and recent phenomenology of Generalized Parton Distributions (GPDs). What sets apart GPDs from their forward kinematic counterparts, the Parton Distribution Functions (PDFs) is the insight they provide on the 3D structure of the nucleon. I will highlight developments of a recent initiative that will boost current investigations within the research program of the future Electron Ion Collider.

        Speaker: Prof. liuti simonetta
      • 37
        Exclusive Drell-Yan for studying GPDs at J-PARC

        It is well known that the DIS and Drell-Yan processes are two key experimental approaches to reveal the partonic structure of nucleons via either the space-like or time-like virtual photons. Conventionally the nucleon GPDs are explored by DVCS and DVMP processes using lepton beam. In this talk I will introduce a complementary measurement of nucleon GPDs by the exclusive pion-induced Drell-Yan process $\pi^- p \to \gamma^* n \to \mu^+\mu^- n$. A feasibility study using E50 high-resolution spectrometer in the coming high-momentum beam line of Hadron Hall at J-PARC has been carried out [PRD 93, 114034]. A clean signal of exclusive Drell-Yan process can be identified in the missing-mass spectrum of triggered dimuon events. Realization of such measurement at J-PARC will open up a new way of accessing nucleon GPDs as well as provide the fundamental test of the universality of GPDs.

        Speaker: Wen-Chen Chang (Academia Sinica (TW))
    • 12:20 PM
    • Session 7: PDFs and MPI I
      Convener: liuti simonetta
      • 38
        New CTEQ global analysis with high precision data from the LHC

        We present the new CTEQ-TEA global analysis of Quantum Chromodynamics (QCD). In this analysis, parton distribution functions (PDFs) of the nucleon are determined within the Hessian method at the next-to-next-to-leading order (NNLO) in perturbative QCD, based on the most recent measurements from the Large Hadron Collider (LHC) and a variety of world experimental collider data. Next-to-leading order (NLO) and leading order (LO) PDFs are also determined. Because of difficulties in fitting both the ATLAS 7 and 8 TeV W and Z vector boson production cross section data, we present two families of PDFs, named CT18 and CT18Z PDFs respectively, without and with the ATLAS 7 TeV W and Z measurements. We study the impact of the CT18 family of PDFs on the theoretical predictions of standard candle cross sections at the LHC and the role of PDF uncertainties.

        Speaker: Tie-Jiun Hou (Northeastern University)
      • 39
        Determination of proton parton distribution functions using ATLAS data

        We present fits to determine parton distribution functions (PDFs) using top-antitop, inclusive W/Z-boson, as well as W+ and W- boson production measurements in association with jets from ATLAS, in combination with deep-inelastic scattering data from HERA. The ATLAS W and Z boson data exhibit sensitivity to the valence quark distributions and the light quark sea composition, whereas the top-quark pair production data have sensitivity to the gluon distribution. The impact of the top-antitop production data is increased by fitting several distributions simultaneously, with the full information on the systematic and statistical correlations between data points. The parton distribution functions extracted using W+jets data show an improved determination of the high-x sea-quark densities, while confirming the unsuppressed strange-quark density at lower x<0.02 found by previous ATLAS analyses.

        Speaker: Gavin Pownall (University of Oxford (GB), DESY (DE))
      • 40
        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 summarized briefly. The xFitter developer’s team also performed several studies recently including determination of pion PDFs, studies of impact on PDFs of forward backward asymmetry in Drell Yan, and investigations of treatment of heavy flavors for charged current DIS processes.

        Speaker: Alexander Glazov (Deutsches Elektronen-Synchrotron (DE))
    • 3:05 PM
    • Session 7: PDFs and MPI II
      Convener: Mario Campanelli (University College London (UK))
      • 41
        Latest results on Soft QCD and DPS from the CMS experiment

        Here we present overview of the recent results on the Soft QCD and Double Parton Scattering

        Speaker: Rajat Gupta (Panjab University (IN))
      • 42
        Measurements of multi-parton interactions at ATLAS

        Measurements of multiple parton scattering in proton-proton collisions provide insight into the structure and long-range low-momentum scale interactions of the proton. In this talk we present two recent measurements using proton-proton collision data collected by the ATLAS experiment. The first measurement determines the double-parton scattering contribution to four-lepton events at √s=8 TeV. An artificial neural net is used to optimise the analysis and an upper limit on the double-parton scattering fraction is set at 0.042, which corresponds to an effective cross section of 1mb. In the second measurement, the underlying event activity is studied in events containing a Z-boson in √s=13 TeV data. Unfolded differential cross sections are presented for charged particle multiplicity and charged particle transverse momentum in regions of azimuth measured with respect to the Z-boson direction. The data are compared to a wide variety of predictions from Monte Carlo event generators.

        Speaker: Robert Astalos (Comenius University (SK))
    • Visit to Science Center
    • 5:30 PM
      Free Time at Center
    • 7:00 PM
    • Session 8: Theoretical developments 1
      Convener: Jun GAO (Shanghai Jiao Tong University, Center for High Energy Physics, Peking University)
      • 43
        From quarkonium wave functions to ${\gamma^* \gamma^* \to \eta_c (1S,2S)}$ transition form factors

        We discuss $\gamma^* \gamma^* \to \eta_c(1S)\, , \,\eta_c(2S)$ transition form factor
        for both virtual photons. The general formula is given.
        We use different models for the $c \bar c$ wave function
        obtained from the solution of the Schr\"odinger equation for
        different $c \bar c$ potentials: harmonic oscillator, Cornell,
        logarithmic, power-law, Coulomb and Buchm\"uller-Tye.
        We compare our results to the BaBar experimental data for $\eta_c(1S)$, for one real
        and one virtual photon. We discuss approaching of
        $Q_1^2 F(Q_1^2,0)$ or $Q_2^2 F(0,Q_2^2)$ to their asymptotic value
        $\frac{8}{3}f_{\eta_{c}}$ predicted by Brodsky and Lepage formalism.
        We discuss applicability of the collinear and/or massless limit and delayed onset of
        asymptotic behaviour.
        We present some examples of two-dimensional
        distributions for $F_{\gamma^* \gamma^* \to \eta_c}(Q_1^2,Q_2^2)$.
        A scaling in $\omega = (Q_1^2 = Q_2^2) / (Q_1^2 + Q_2^2)$ was obtained.
        A factorization breaking measure is proposed and factorization breaking effects are quantified and shown
        to be weakly model dependent.
        The cross section for the $e^+ e^- \to e^+ e^- \eta_c$ reaction are given for double
        tagging ($e^{+}$ and $e^{-}$) case and the effect of $(Q_1^2,Q_2^2)$ dependence of the
        transition form factor is quantified.

        I. Babiarz, V. Goncalves, R. Pasechnik, W. Schafer and A. Szczurek,
        a paper in print i Phys. Rev. D (see also arXiv)

        Speaker: Prof. Antoni Szczurek (Institute of Nuclear Physics)
      • 44
        Extracting jet transport coefficient of cold nuclear matter

        Quantifying the differences between nuclear and hadronic collisions, phenomenological known as medium modification due to multiple scatterings between the hard probe and medium, can provide a solid baseline for unambiguous identification of the fundamental medium property. In this talk, we consider parton propagation in cold nuclear matter within the framework of high twist expansion, which has been shown to be a successful approach to describe the multiple scattering effect as observed in experiment. Through global analysis of world data on transverse momentum broadening of single particle, transverse momentum imbalance of two particle, as well as nuclear modification factor of single particle in electron-nucleus and proton-nucleus collisions, we perform the first extraction of jet transport coefficient (qhat) for cold nuclear matter. This provide the first evidence that the medium transport property, rather than a constant value as commonly used in heavy ion collisions, depends on the probing scale similar to that in standard parton distribution functions of proton.

        Speaker: Hongxi Xing
      • 45
        Quasi Parton Distribution Functions for Gluons

        Parton distribution functions (PDFs) are mandatory inputs in high energy scattering and also play an important role in searching for new physics at high energy. The recently proposed large momentum effective theory allows one to access the PDFs from first principle Lattice QCD. In this talk, I will discuss the recent progresses on quasi-PDFs, in particular on the gluon quasi-PDFs.

        Speaker: Wei Wang (SJTU)
    • 9:45 AM
    • Session 8: Theoretical developments 2
      Convener: Antoni Szczurek (Institute of Nuclear Physics)
      • 46
        Quantum Computing and lattice gauge theories

        to be provided by Richard Brower.

        Speaker: Richard Brower (Boston Univ.)
      • 47
        Tensor network in complex scalar theory toward lattice studies of AdS/CFT

        Sign problem is an obstacle in lattice studies of supersymmetric gauge theories including a numerical verification of AdS/CFT. Tensor network is an attractive approach to overcome this problem. We present a numerical result of the tensor network approach in two-dimensional complex phi^4 theory with finite chemical potential.

        Speaker: Daisuke Kadoh (Chulalongkorn)
      • 48
        What QCD teaches us about Quantum Gravity, and vise versa

        For long time, gravity is used for learning dynamical aspects of QCD, because holography connects gravity and QFT. In this talk, I will review the opposite direction: learning about gravity from QFT. In particular, I will focus on the quantum nature of black hole. Techniques developed among QCD-practitioners turned out to be useful for quantum gravity. At the same time, quantum gravity leads to new understanding about QCD and QFT. As an example, I introduce a new symmetry breaking mechanism motivated by evaporating black hole a la Hawking.

        Speaker: Dr Masanori Hanada
    • 11:45 AM
    • Session 9: Conference Summary and Panel Session
      • 49
        Conference Summary
        Speaker: Bob Hirosky (University of Virginia (US))
      • 50
        Panel Discussion
    • Session 9: Closing Remarks
      Convener: Chung-I Tan
    • 2:40 PM
      Break and departure from ICISE