Conveners
Strong Interactions and Hadron Physics: 1
- Ralf Seidl (RIKEN)
Strong Interactions and Hadron Physics: 2
- In Kwon Yoo (Pusan National University (KR))
Strong Interactions and Hadron Physics: 3
- Sungtae Cho (Kangwon National University)
Strong Interactions and Hadron Physics: 4
- Leo Piilonen (Virginia Tech)
Strong Interactions and Hadron Physics: 5
- Patrick Fritzsch (CERN)
Strong Interactions and Hadron Physics: 6
- Henning Kirschenmann (Helsinki Institute of Physics (FI))
Strong Interactions and Hadron Physics: 7
- Brigitte Vachon (McGill University, (CA))
Strong Interactions and Hadron Physics: 8
- Enrico Rinaldi (Lawrence Livermore National Laboratory)
Strong Interactions and Hadron Physics: 9
- Claire Gwenlan (University of Oxford (GB))
Strong Interactions and Hadron Physics: 10
- Jibo He (University of Chinese Academy of Sciences (CN))
Strong Interactions and Hadron Physics: 11
- Anthony Sebastian Francis (CERN)
Strong Interactions and Hadron Physics: 12
- Bryan FULSOM (Pacific Northwest National Laboratory)
With excellent performance the Compact Muon Solenoid (CMS) experiment has made a number of key observations in the diffractive and exclusive processes and hence in probing the Standard model in a unique way. This presentation will cover recent results on the measurement of diffractive and exclusive processes using data recorded by CMS detector at the LHC.
The total pp cross section is a fundamental observable at the LHC. It can be derived from the measurement of the elastic cross section, using the optical theorem. Measurements of the elastic proton-proton cross section were performed at a center-of-mass energy of 8 TeV at various settings of the beam optics using the ALFA detector.
The ALFA detector is also used to tag forward protons in...
Exclusive photoproduction of $\rho(770)$ vector mesons is studied using the H1 detector at HERA. A sample of about $700000$ decays $\rho\to\pi^{+}\pi^{-}$ was collected in the years 2006-2007, using the H1 fast track trigger. It corresponds to an integrated luminosity of $1.3$ pb$^{-1}$. The sample is used to study cross-sections as a function of the invariant mass $m_{\pi\pi}$ of the decay...
Exclusive processes at high momentum transfer, such as Deeply Virtual Compton Scattering (DVCS) access the Generalized Parton Distributions (GPDs) of the nucleon. GPDs offer the exciting possibility of mapping the 3-D internal structure of protons and neutrons by providing a transverse image of the constituents as a function of their longitudinal momentum.
A vigorous experimental program is...
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...
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.
Parton distribution functions (PDFs) are crucial ingredients for measurements at hadron colliders, since they describe the initial states and therefore critically impact the precision of cross section predictions for observables. This talk will review recent precision analyses, where the PDFs play an important role and discuss the impact of several new ATLAS cross-section measurements on PDFs...
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 later HE-LHC (LHeC) or eventually the FCC hadron beams (FCC-eh). It would deliver electron-proton collisions with centre-of-mass energies in the range 0.3-3.5 TeV, and luminosities exceeding $10^{34}$ cm$^{−2}$s$^{−1}$. In this talk we will present new...
The knowledge of the proton parton densities for large x is very important in the search for new physics signals at the LHC. For Bjorken-x larger than 0.6 they are however poorly constrained by the data used in extracting the proton parton density functions (PDFs) and different pdf sets have large uncertainties, and differ considerably, in this regime. We compare the pdf sets most widely...
A phenomenological study of the final combined HERA data on inclusive deep inelastic scattering (DIS) has been performed. The data are presented and investigated for a kinematic range extending from values of the four-momentum transfer, $Q^2$, above $10^4$ GeV$^2$ down to the lowest values observable at
HERA of $Q^2 = 0.045$ GeV$^2$ and Bjorken $x$, $x_{\rm Bj} = 6 \times 10^{−7}$. The data...
The production of charm quarks in charged current interactions at HERA is investigated using the ZEUS detector. The present analysis considers measurements taken in HERA II period (2003 - 2007) where major detector upgrades were implemented at ZEUS. With an integrated luminosity of about 350 pb$^{-1}$), the HERA II data has enough statistics to probe the strangeness in the proton via charm...
The branching fraction of the decay Bs → Ds X has been measured by Belle and other experiments, but with indirect methods which have model-dependent limitations. We report a direct measurement of this decay by tagging one Bs from Y(5S) with semi-leptonic decay (Bs → Ds l nu), where several Ds decay modes are combined to increase the total statics. We also report a search for eta and eta'...
The hadronic transitions involving an eta meson, thoroughly studied by Belle, are the largest transitions from Y(4S) to the narrow bottomonia. The transition Υ(4S)→η′Υ(1S) yields insights on the quark content of the pseudoscalar mesons, and on the mechanism of heavy quark spin symmetry breaking, if compared with the eta transitions, We report the first observation of this transition, with the...
We report on recent studies of quarkonium decays performed 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 $\gamma_{ISR}$ is produced via...
The Bc meson, the heaviest amongst known meson, decays through the weak interaction. Its double heavy quark content make it an interesting laboratory for test of effective theories of the strong interaction with a unique setting for production, decay and spectroscopy studies. This talk presents recent progress on Bc decays obtained at LHCb.
Beauty production in events containing two muons in the final state has been measured with the ZEUS detector at HERA II. A low transverse-momentum threshold for muon identification, in combination with the large rapidity coverage of the ZEUS muon system and the upgraded ZEUS tracker, gives access to almost the full phase space for beauty production. The total cross section for beauty...
$B$ mesons are the lightest mesons which can decay to various final states containing different baryons. Up to now, the 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, averaged on neutral and charged $B$ mesons at less...
The spectroscopy of excited hadronic states in the beauty sector, double heavy hadrons and quarkonia provides a rich proofing ground for effective theories of the strong interaction. The unique data set collected during runs 1 and 2 of the LHC have lead to the observation of several new states, interesting decay modes and has enabled precision mass measurements of known resonances. Here we...
LHCb continues to expand its world-leading sample of charmed hadrons collected during LHC’s Run 1 and Run 2. Recent results on charm production and charm hadron lifetimes are presented.
LHCb continues to expand its world-leading sample of charmed hadrons collected during LHC’s Run 1 and Run 2. With this data set, LHCb is discovering many previously unobserved charmed states and making the most precise determinations of the properties of these states. LHCb’s latest work on the spectroscopy of charmed hadrons is presented.
Measurements of $D^{∗}(2010)$ meson production in diffractive deep inelastic scattering ($5 < Q^2 < 100$ GeV$^2$) are presented which are based on HERA data recorded at a centre-of-mass energy $\sqrt{s} = 319$ GeV with an integrated luminosity of $287$ pb$^−1$. The reaction $ep\to eXY$ is studied, where the system $X$, containing at least one $D^{∗}(2010)$ meson, is separated from a leading...
In proton-proton (pp) collisions, open heavy-flavour hadrons are valuable tools for testing perturbative Quantum Chromo-Dynamics (pQCD) calculations. Indeed, the large heavy-quark masses (with respect to the QCD scale parameter) allow to calculate the heavy-quark production cross section, as perturbation series in $\alpha_S$ down to $p_{\mathrm T}=0$.
The ALICE experiment has measured D...
We measure the mass difference, $\Delta m_+$, between the $D^{*}(2010)^+$ and the $D^+$, using the decay chain $D^{*}(2010)^+\to D^+ \pi^0 $ with $ D^+ \to K^- \pi^+ \pi^+$. The data were recorded with the BABAR detector at center-of-mass energies at and near the $\Upsilon(4S)$ resonance, and correspond to an integrated luminosity of approximately $468 \, \mbox{fb}^{-1}$. We measure $\Delta...
The associated production of vector boson with quarkonia is a key observable for understanding the quarkonium production mechanisms, including the separation of single and double parton scattering components.
This talk will present the latest differential measurements from ATLAS of (associated-) quarkonium production
Recent results on the production of beauty and charm at the CMS detector, based on data collected at Run 1 and Run 2 of LHC are presented. Measurements of single and double quarkonium production, Lambda_b polarization, open charm and B hadrons cross sections and ratios are reported.
There is an intriguing discrepancy in the measurements of the neutron lifetime. The almost 4$\sigma$ difference has recently been highlighted due to new high-precision experiments using ultra cold trapped neutrons and it could indicate the existence of new physics.
Thanks to the Standard Model relation between the lifetime and the axial coupling $g_A$ of the neutron, which governs it's...
We investigate the possibility of $qq^\prime \bar Q \bar Q^\prime$ tetraquark bound states using $n_f=2+1$ lattice QCD with pion masses $\simeq 164$, $299$ and $415$ MeV. Two types of lattice interpolating operator are chosen, reflecting first diquark-antidiquark and second meson-meson structure. Performing variational analysis using these operators and their mixings, we determine the ground...
We determine the charm quark mass $m_c(m_c)$ from QCD sum rules of moments of the vector current correlator calculated in perturbative QCD. Only experimental data for the charm resonances below the continuum threshold are needed in our approach, while the continuum contribution is determined by requiring self-consistency between various sum rules, including the one for the zeroth moment....
In this talk, basic properties of QCD condensates will be presented, together with theirs relation to the operator product expansion (OPE) and the two-point and three-point Green functions constructed of chiral currents. Next, we will discuss our newest results for contribution of the QCD condensates with dimension D<6 to the Green functions calculated within the framework of chPT/RChT, i.e....
A program of measuring the light hadrons production in exclusive $e^+e^- \to$ hadrons processes is in place at BABAR, with the aim to improve the calculation of the hadronic contribution to the muon $g-2$. We present the most recent results obtained by using the full data set of about 470 fb$^{-1}$ collected by the BABAR experiment at the PEP-II $e^+e^-$ collider at a center-of-mass energy of...
The inclusive cross sections for di-hadrons of charged pions and kaons (e+e-→hhX), hyperons and charmed baryons in e+e- annihilation are reported. For di-hadrons of charged pions and kaons, the cross sections are obtained as a function of the total fractional energy and invariant mass for any di-hadron combination in the same hemisphere and di-hadron fragmentation functions are probed. For...
Charm-quark hadronisation can be investigated by measuring the relative abundance of various particle species, in particular non-strange D mesons ($\rm{D^0}$, $\rm{D^+}$, $\rm{D^{*+}}$), $\rm{D_s^+}$ mesons, and charm baryons ($\rm{\Lambda_{c}^+}$, $\rm{\Xi_c^0}$). The high precision tracking, good vertexing capabilities and excellent particle identification granted by the ALICE apparatus...
Jet substructure observables have significantly extended the search program for physics beyond the Standard Model at the Large Hadron Collider. The state-of-the-art tools have been motivated by theoretical calculations, but there has never been a direct comparison between data and calculations of jet substructure observables that are accurate beyond leading-logarithm approximation. Such...
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...
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.
A precision measurement of jet cross sections in neutral current deep-inelastic scattering for photon virtualities $5.5 < Q^2 < 80$ GeV$^2$ and inelasticities $0.2 < y < 0.6$ is presented, using data taken with the H1 detector at HERA, corresponding to an integrated luminosity of 290 pb$^{−1}$. Double-differential inclusive jet, dijet and trijet cross sections are measured simultaneously and...
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.
Perturbative QCD calculations at next-to-leading order are available for the jet production in pp collisions since several years and next-to-next-to leading order calculations also became available recently. In this talk, we present the latest results from the ATLAS collaboration for inclusive jets and dijets, measured at center of mass energies of 8 and 13 TeV. All measured cross-sections are...
We calculate quark and gluon jet fraction in multi-jet final states at the LHC, which is based on perturbative QCD at next-to-double logarithmic accuracy. We find a measurable scaling pattern of the fraction. This is related to a performance of new physics searches using quark-gluon jet discrimination in multi-jet final states, and would be useful for more understanding of QCD and tuning of...
We present a first-principle determination of the Λ parameter and the strong coupling at the Z pole mass. Computing the nonperturbative running of the coupling in the range from 200 MeV to 70 GeV, and using experimental input values for the masses and decay constants of the pion and the kaon, we obtain α(mZ)=0.11852(84). The nonperturbative running up to very high energies guarantees that...
The strong coupling constant $\alpha_s$ 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...
Measurements of open charm and beauty production cross sections in deep inelastic $ep$ scattering at HERA from the H1 and ZEUS Collaborations are combined. Reduced cross sections are obtained in the kinematic range of negative four-momentum transfer squared of the photon $2.5$ GeV$^2\le Q^2 \le 2000$ GeV$^2$ and Bjorken scaling variable $3 \cdot 10^{-5} \le x_{\rm Bj} \le 5 \cdot 10^{-2}$. The...
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 numerous cross section measurements of prompt photon production, among which are a precise measurement of the production of isolated prompt photons in association with heavy flavor...
We present the current status of recent developments in the theory and application of IR-improved QED$\otimes$QCD resummation methods, realized by MC event generator methods, for LHC and FCC physics scenarios.
e+e- collisions at a Future Circular Collider with tens of ab^-1 integrated luminosities provide unparalleled conditions to carry out unique high-precision QCD and two-photon-fusion studies. The QCD and gamma-gamma physics perspectives at the FCC-ee will be summarized focusing on high-accuracy measurements of 1) the QCD coupling alpha_s [1], 2) parton radiation and fragmentation [2], and 3) SM...
The DIRAC experiment at the CERN PS accelerator observed for the first time the long-lived hydrogenlike π+π− atoms. Atoms were produced by PS proton beam on the Be target. Part of the atoms in the long-lived states crossed the gap of 96 mm and then broken in the Platinum foil of 2.1 µm. producing π+π− pairs(atomic pairs). From the analysis of the $n_A^L = 436_{-61}^{+157}$ observed atomic...
The study of the associated production of vector bosons and jets constitutes an excellent testbench to check numerous QCD predictions. Total and differential cross sections of vector bosons produced in association with jets has been studied at both 8 and 13 TeV center-of-mass energies. Differential distributions as function of a broad range of kinematical observables are measured and compared...
The associated production of vector bosons, W or Z, and jets originating from heavy-flavour quarks is a large background source in measurements of several standard model processes, Higgs boson studies, and many searches for physics beyond the SM. The study of events with one or two well-identified and isolated leptons accompanied by heavy-flavour jets is crucial to refine the theoretical...
We report on the latest measurement on the production of W bosons in association with jets at 8 TeV and compare our results to the latest theoretical predictions. Differential cross sections for events with one or two jets are presented for a range of observables, including jet transverse momenta and rapidities, the scalar sum of transverse momenta of the visible particles in the event, and...
The forward acceptance of LHCb, 2.0 < y < 5.0, provides a complementary reach to the general purpose detectors at the LHC. LHCb measurements of the pp inelastic cross-section, J/psi production in jets, kinematic correlations between b and b-bar hadrons, and Bose Einstein correlations are discussed. Prompt J/psi production is found to be less isolated than predicted in LO NRQCD.
We present recent results on Minimum Bias, Underlying Events and Double Parton Scattering using data recorded by CMS detector at the LHC. The results on the measurement of the underlying event using leading tracks, jets, and Drell-Yan processes are presented. Double parton scattering is investigated in several final states including vector bosons and multi-jets, and the results are compared to...
Quarkonium production in proton-proton ($pp$) collision provides interesting means to study the parton content and their correlations in the proton. Recent experimental LHC and Tevatron data of $J/\psi+Z$, $J/\psi+W$ and $J/\psi+J/\psi$ production suggest the relevance of double parton scatterings (DPSs) as opposed to single parton scatterings (SPSs). In this talk, we review the corresponding...
Recent results on study of exclusive processes of $e^+e^−$ annihilation into hadrons below 2 GeV obtained at the SND detector are presented. The analyses are based on data collected at the VEPP-2M and VEPP-2000 colliders. In particular, we present the measurements of the $e^+e^-\to \eta\pi^+\pi^-$, $e^+e^-\to \eta K^+K^-$, $e^+e^-\to K_S K_L \pi^0$ cross sections, and the preliminary results...
We report measurement of the decays of the Ωc0 charmed baryon into hadronic final states and observe excited Ωc charmed baryons in the decay mode Ξc+K- including Ωc(3000) , Ωc(3050), Ωc(3066), and Ωc(3090). In addition, We report the first observation of the Ξc(2930)0 charmed-strange baryon with a significance greater than 5σ in its decay to K-Λc+ in B- →K-Λc+Λc- decays. The branching...
Hyperons are a powerful diagnostic tool that sheds light on some of the most challenging questions in contemporary physics. One is how and why the strong force confines quarks and gluons into composite systems, e.g. protons. The central question is: What happens if we replace one of the light quarks in a proton, with a heavier quark? In particular, strange systems probe the strong interaction...
Searches for, and measurements of exotic states are studied with the ATLAS detector. The latest results from ATLAS on exotic (tetra- / pentaquark) states are presented. In addition, recent results on heavy flavour production measurements are reported in the Bu and Bc systems.
We study the process $e^+e^-\to e^+e^- \eta'$ in the double-tag mode and measure for the first time the $\gamma^{\star}\gamma^{\star} \to \eta'$ transition form factor $F_{\eta'}(Q_1^2, Q_2^2)$ in the momentum-transfer
range $2 < Q_1^2, Q_2^2 < 60$ GeV$^2$. The analysis is based on data with an integrated luminosity 469 fb$^{-1}$ collected at the PEP-II $e^+e^-$ collider with the BABAR...
We study the production of a narrow structure $X^{\pm}(5568)$ decaying to $B^0_s\pi^{\pm}$ produced in $10.4\ \rm fb^{−1}$ of $p\bar p$ collisions recorded by the D0 detector at the Fermilab Tevatron collider at $\sqrt s=1.96\ $TeV. We report evidence for the production of $X^{\pm}(5568)$ using the semileptonic mode $B^0_s \to \mu^{\mp}D_s^{\pm}X$ with $ D_s^{\pm}\to\phi\pi^{\pm}$. The...
With about 12 $fb^{-1}$ of collected data useful for the study of X Y Z resonances, BESIII continues the exploration of these exotic charmonium-like states. In these talk, recent results of the measurements of the line-shape of $e^+ e^- \to \pi^0 \pi^0 \psi(3686), K K J/\psi$, and $\pi^+ D^0 D^{*-}$, as well as the $J^P$ determination of $Z_c(3900)$ and $Z_c(3900)$ observed in $e^+ e^- \to...
Using large data samples of di-muon events, CMS has performed detailed measurements and searches for new states in the field of exotic quarkonia. We report on several recent results including, among the others: the measurement of the X(3872) properties, the investigation of the B+ to J/ψ φ K+ decay revealing two structures in the J/ψ φ mass spectrum, one of which compatible with the Y(4140)...
Study of the processes e+e- →J/ψDD and D()+- D-+ by Belle is updated, where a new charmonium(-like) state X(3860) is observed with a significance of 6.5σ using full amplitude analysis in J/ψDD, and the first angular analysis is performed in D()+- D-+. We present the measurement of the absolute branching fractions of B+→Xcc K+ and B+→D()0 π+ decays. Here, Xcc denotes ηc, J/ψ, χc0, χc1,...
LHCb exploits decays of beauty hadrons as well as direct production in proton-proton collisions to investigate exotic mesons, especially in the charmonium mass region. The large data samples collected during Run I and II of the LHC open new possibilities for precision studies of these states. Recent results on exotic meson spectroscopy will be presented.
With the discovery of two pentaquark candidates at LHCb a new field of baryon spectroscopy has been opened. The unique data samples on beauty baryon decays collected at the LHC during its runs I and II provide opportunities to further study the spectrum of exotic heavy baryons. This presentation will highlight recent progress on establishing new baryonic multiparticle decay modes of beauty...
The Belle II experiment, now operating at the KEK laboratory in Japan, is a substantial upgrade of both the Belle detector and the KEKB $e^+ e^-$accelerator. It aims to collect 50 times more data than existing B-Factory samples. 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...
For the first time the branching ratio and the angular distribution of the decay $\psi (3686) \to n \bar{n}$ have been measured. At the same time also the branching ratio and angular distribution of the decay $\psi (3686) \to p \bar{p}$ have been measured with unprecedented precision. It turns out that the two branching ratio are quite close, implying that the phase between strong and...
At present the world's largest sample of 1.3 billion J/psi decay has been collected by the BESIII detector, which provides a unique opportunity to investigate light meson decays. The $a^0(980)-f^0(980)$ mixing is an important probe to the nature of those two light scalars. The first observation of $a^0(980)-f^0(980)$ mixing will be reported. The $\eta$ and $\eta'$ hadronic decays are sensitive...
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- 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...
The CASTOR calorimeter at CMS measures the energy of particles emitted with pseudorapidity between -5.2 and -6.6. It has been operating since the startup of the LHC in 2009 and has taken data in pp, pPb, and PbPb collisions at various centre-of-mass energies during run 1 and run 2. In this presentation we give an overview of some important and unique results obtained with CASTOR, with emphasis...
