Conveners
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 1: Quarkonium + Exotic Hadrons 1
- Clara Peset (Technische Universität München)
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 2: Quarkonium + Exotic Hadrons 2
- Miguel Ángel Escobedo Espinosa (Instituto Galego de Fisica de Altas Enerxías (IGFAE))
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 3: QGP
- Anne Sickles (University of Illinois)
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 3: Jets
- Liliana Apolinário (LIP)
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 4: Heavy Flavor (HF)
- Frank Geurts (Rice University)
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 5
- Rafał Maciuła (Institute of Nucelar Physics PAN)
QCD with Heavy Flavors and Hadronic Final States: Parallel Sessions 5
- Alan Price (Siegen University)
QCD with Heavy Flavors and Hadronic Final States
- Mariola Klusek-Gawenda (Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland)
Threshold photoproduction of charmonium at JLab and EIC can be used to extract the distribution of mass inside the proton by using the scale anomaly of QCD and the multipole expansion. Theoretical analysis of this problem will be presented and confronted with the first experimental data from JLab.
The suppression of $J/\psi$ production caused by the color-screening effect in heavy-ion collisions is considered as an evidence of the creation of quark-gluon plasma. To interpret the observed suppression in heavy-ion collisions, a good understanding of its production mechanism in p+p collisions is needed. However, the production of $J/\psi$ in hadronic collisions remains not fully understood...
We study inclusive $J/\psi$ photoproduction at NLO at large $P_T$ at HERA and the EIC. Our computation includes NLO QCD leading P_T corrections, QED contributions via an off-shell photon as well as those from $J/\psi$+charm channels. For the latter, we employ the variable-flavour-number scheme. Our results are found to agree with the latest HERA data by H1 and provide, for the first time, a...
Recent results from the ATLAS experiment on charmonium production will be presented. The measurement of the associated production of the J/psi meson and a photon, including an estimation of the transverse-momentum-dependent distribution function of linearly polarized gluons in an unpolarized proton, will be discussed. The measurement of J/psi and psi(2S) differential cross sections at large...
Transverse momentum dependent parton distribution functions (TMDs) are extensions of the well- known collinear PDFs. They contain, apart from the usual x- and scale dependence, also information on the intrinsic transverse momentum carried by the parton, and on the spin correlations.
Experimentally, not so much is known about gluon TMDs, since they are subleading with respect to their quark...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is an upgrade of the B factory facility at KEK in Tsukuba, Japan. The experiment began operation in 2019 and aims to record a factor of 50 times more data than its predecessor. Belle II is uniquely capable of studying the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. First...
We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small x, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed...
Recent results from the ATLAS experiment on exotic heavy hadrons will be presented. Studies of the Pentaquarks with hidden charm in the Lambda_b decays in proton-proton collisions at 7 - 8 TeV will be discussed. New results on the heavy tetraquarks in the Run 2 data at 13 TeV will also be reported.
We discuss the production mechanism of a new state, a fully charm tetraquark, discovered recently by the LHCb at M = 6.9 GeV in the $J/\psi J/\psi$ channel. Both single parton scattering (SPS) and double parton scattering (DPS) mechanisms are considered. We calculate the distribution in the invariant mass of the four-quark system $M_{4c}$ for SPS and DPS production of $c c \bar c \bar...
Exotic hadrons, which are composed of more than three valence quarks, can provide new insights into the internal structure and dynamics of hadrons, thus improving our knowledge of the non-perturbative regime of QCD. The data collected by the LHCb experiment provides unique opportunities for precise measurement of properties of established exotic hadrons and search for new ones. This talk...
In this talk, we present a thorough analysis of $\eta_c(1S, 2S)$ and $\chi_{c0},\chi_{b0}$ quarkonia hadroproduction in $k_T$-factorisation in the framework of the light-front potential approach for the quarkonium wave function.
The off-shell matrix elements for the $g^{*}g^{*}\to\eta_c, \chi_{c0}$
vertices are derived in terms of the quarkonium light-front wave function.
We discuss the...
The large data sample accumulated by the Belle experiment at the KEKB asymmetric-energy e^{+}e^{-} collider provides a unique opportunity to perform studies related to hadron spectroscopy utilising various production mechanisms. We report on radiative decays of excited Xi_c baryons, study of Xi_c → Xi_0 K+ K0, branching fraction measurement of Lambda_c^+, determination of the spin and parity...
Heavy quarkonium production provides valuable opportunities for exploring fundamental QCD dynamics with multiple scales. Thus far, NRQCD factorization has been successful in describing many features of the data. Despite many theoretical efforts at NLO accuracy, however, there are still unresolved issues, including the lack of a full understanding of quarkonium polarization at high $p_T$. One...
In hadronic collisions, beauty quarks are produced in hard-scattering processes with large momentum transfer. The production of hadrons containing beauty quarks provides a very important test of perturbative QCD calculations in pp collisions. The measurement of the production of beauty-strange mesons relative to that of beauty hadrons without strange-quark content is useful to study the...
Droplets of quark-gluon plasma produced in heavy-ion collisions rapidly evolve expanding and cooling. During considerable part of this dynamics the system can be described within relativistic hydrodynamics. Recently, there were some attempts to include effects of the medium motion to the jet energy loss and jet modification calculations in a variety of models. Here we will present the first...
Light meson measurements in high-energy proton-nucleus collisions provide a probe to study the physics of strongly interacting matter and the quark-gluon plasma. In particular, measuring the nuclear modification factor, where the particle production in p-A is compared to a baseline proton-proton reference which is scaled to account for nuclear geometry, provides important insight to the...
A. SHABETAI (for the ALICE Collaboration)
The measurement of jet production and structure observables in pp collisions provides significant tests of perturbative QCD. Jet measurements in proton-lead collisions enable study of cold nuclear matter effects. Jets are generated in the early stages of ultra-relativistic heavy-ion collisions and provide unique channels for probing the quark-gluon...
Using the unification of chiral SU(3) model and QCD sum rules, we deduce the in-medium properties of $K^\pm_1$ meson. Within chiral SU(3) model, medium modified gluon and quark condensates are evaluated through their interactions with the scalar fields ($\sigma$, $\zeta$, $\delta$ and $\chi$). These condensates are further used as input in the Borel transformed equations of QCD sum rules to...
Studies on the production of light- and heavy-flavour baryons are of prominent importance to characterise the partonic phase created in ultrarelativistic heavy-ion collisions and to investigate hadronization mechanisms at the LHC, in particular through the study of the evolution of the baryon-over-meson production ratio as a function of the transverse momentum. Measurements performed in pp and...
Jets are algorithmic proxies of hard scattered partons, i.e. quarks/gluons, in high energy collisions. Current jet measurements utilize algorithms that cluster objects, either particles from an event generator or charged tracks/calorimeter towers in experiments, iteratively depending on the distance between objects and a momentum threshold. These clustering algorithms contain additional...
We propose the inclusive hadroproduction of a heavy-light dijet system, as a new channel for the investigation of high energy QCD. We build up an hybrid factorization that incorporates a partial next-to-leading BFKL resummation inside the standard collinear description of observables. We present a detailed analysis of different observables: cross-section summed over azimuthal angles and...
Jets are collimated sprays of hadrons created by the fragmentation of high energy partons, and serve as an experimental tool for studying quantum chromodynamics. In particular, we can explore the properties of parton showers and jet evolution by measuring jet sub-structure. One of the techniques that allows experimental access to the parton shower is the jet grooming technique called SoftDrop....
The LHCb experiment at the Large Hadron Collider (LHC) is suited for studying how hadrons are formed from scattered quarks and gluons, collectively referred to as partons, in energetic proton-proton collisions. The hadronization process, conventionally described in terms of non-perturbative fragmentation functions in collinear factorization, can be learned in full picture at present via...
Measurements of the internal properties of jets allow QCD to be studied in a new energy regime. In this talk, we discuss recent measurements of jet substructure and jet fragmentation, which were performed using data collected by the ATLAS experiment at a centre-of-mass energy of √s=13 TeV. For jet substructure, a comprehensive suite of substructure observables are measured for jets...
In this contribution a measurement is presented of several observables that are sensitive to the fragmentation of b-quarks. The measurement is based on an analysis of 36 fb−1 of sqrt(s)=13 TeV LHC data. Jets containing b-hadrons are obtained from a sample of dileptonic ttbar events. The associated set of charged-particle tracks is separated into those from the primary pp interaction vertex and...
We develop a systematic treatment of heavy-flavor hadroproduction in the framework of the General-Mass Variable-Flavor-Number Scheme (GM-VFNS). By following the idea of the Simplified-ACOT-𝜒 Scheme in Deep Inelastic Scattering (DIS), we categorize the open heavy-flavor diagrams into Flavor Excitation (FE) and Flavor Creation (FC) contributions. In order to avoid double-counting, overlapping...
Measurements of the properties of b-hadrons and quarkonia can help deepen our understanding of strong interaction. The large b- and c-hadron yields at LHCb and excellent performance of the LHCb detector make it an ideal laboratory for such studies. This talk presents the recent experimental studies on production, decay and spectroscopy of conventional b-hadrons and quarkonia at LHCb.
In this talk we discuss different mechanisms of open-heavy flavor meson and heavy quarkonia production which contribute to inclusive and single diffractive (SD) cross-sections.
For the case of inclusive production of open heavy flavor mesons, we evaluated explicitly the contributions of the two-Pomeron and the three-Pomeron fusion. We found that the latter mechanism is significant for the...
Recent results from the ATLAS experiment on the B_c production and decays will be presented. The measurement of the ratios of the B_c+ and B+ production cross sections in proton-proton collisions at 8 TeV will be discussed.
The ATLAS experiment has performed accurate measurements of mixing and CP violation in the neutral B mesons, and also of rare processes happening in electroweak...
I present results for soft anomalous dimensions through three loops for several processes involving the production of top quarks. I also present some numerical results for total cross sections as well as single- and double-differential distributions, and I show that soft-gluon corrections are dominant for a large range of collider energies.
atest results on inclusive and differential top quark pair and single top quark production cross sections are presented using proton-proton collision data collected by the CMS experiment. The differential 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 results are confronted with precise theory...
Rare two-body decays of the top quark into a neutral bottom-quark meson plus an up- or charm-quark: $t\to {\overline B}^0+ u, c$; $t\to {\overline B}^0_{s}+ c,u$; and $t \to \Upsilon(nS)+ c,u$, are studied for the first time. The corresponding partials widths are computed at leading order in the non-relativistic QCD framework. The sums of all two-body branching ratios amount to $\mathcal{B}(t...
The hard scattering process in which two top-quark-antiquark pairs are produced is also called four-top-quarks production and is predicted to have a small cross-section of 12 fb in the standard model. This very rare process has not been observed yet. The background is mainly given by top-quark-antiquark production in association with heavy flavor jets. In this presentation, two analyses are...
Measurements of top quark properties using data collected by the CMS experiment at 13 TeV are presented. They include direct measurements of properties or extractions using differential cross section measurements. Among them, the latest results on top mass and its running, top Yukawa coupling, the top sector of the CKM matrix, ttbar forward backward asymmetry, CP violation effects in top quark...
We discuss the role of intrinsic charm (IC) in the nucleon for forward production of $c$-quark (or $\bar c$-antiquark) in proton-proton collisions for low and high energies. The calculations are performed in collinear-factorization approach with on-shell partons, $k_T$-factorization approach with off-shell partons as well as in a hybrid approach using collinear charm distributions and...
The Pierre Auger Observatory is the world largest extensive air shower
detector. Based on two detection techniques, namely fluorescence telescopes
for the observation of the longitudinal development and water Cherenkov
detectors for particles at ground, this experiment can be used not only as a
cosmic ray observatory, but also to study the basic properties of hadronic
interactions...
The energy-energy correlator (EEC) is an event shape observable which probes the angular correlations of energy depositions in detectors at high energy collider facilities, which it has been extensively investigated in the context of precision QCD. In this work we introduce a novel definition of EEC adapted to the Breit frame in deep-inelastic scattering. In the back-to-back limit, the...
The factorization of short-distance partonic cross sections from universal non-perturbatively-generated kinematic distributions is fundamental to phenomenology at hadron colliders. It has been predicted however that certain observables cannot be factorized in the usual way, even at high energies. Specifically, observables that are sensitive to momenta transverse to the direction of an...
We present new results on 2- and 3-loop heavy flavor corrections
to polarized and unpolarized DIS.
This includes a consistent treatment of
$\gamma_5$ which enables the extension
of massive operator matrix elements and the variable flavor
number scheme to the polarized case.
The hadronization or fragmentation, where a struck quark transforms into color-neutral hadrons, is an effective tool to probe the confinement dynamics as well as the characteristic time-scales involved in the process. These time-scales elucidate our understanding of the color-neutralization and subsequent non-perturbative formation of the observed hadrons. This talk will report the first-ever...
We present results of our calculations of cross sections of inclusive and diffractive dijet photoproduction in ultraperipheral collisions (UPCs) of heavy ions at the CERN Large Hadron Collider using next-to-leading order perturbative QCD. We demonstrate that our approach provides a good description of the dijet cross section measured by the ATLAS Collaboration, which exhibits 10-20% nuclear...
n recent years there has been a great deal of effort to search for collectivity in small collision systems. Ultra-peripheral pPb events offer the possibility to study γ-proton collisions at a center of mass energy of several hundred GeV. Such collisions provide a new arena in which to search for collectivity. The CMS experiment has identified a large sample of γ-Pb collisions by selecting very...
We report a study of two-particle angular correlations in
deep-inelastic scattering off a proton target measured with
the CLAS12 detector at Jefferson Lab. We discuss both
pion-pion and pion-proton correlation functions. Such measurements
complement ongoing studies at collider experiments and addresses open
questions regarding hypothetical collective behaviour in "small systems". ...
Charged particle multiplicity spectra and hadron entropies are measured using the H1 detector at HERA, where positrons of energy 27.6 GeV collided with protons of energy 920 GeV. For the analysis, data on deep-inelastic scattering in the momentum transfer range 5<𝑄2<100 GeV2 and inelasticity range 0.0375<𝑦<0.6 are used. The observed multiplicity spectra of charged hadrons are compared to Monte...
A parton branching (PB) formulation for the QCD evolution of transverse momentum dependent (TMD) parton distribution functions has been recently developed. With the implementation of this in the evolution program updfevolv and the parton shower Monte Carlo event generator Cascade3, PB TMD predictions for observables in broad kinematic regimes can be made. In this talk I focus on recent PB TMD...
We study the nuclear modification for the large Bjorken-$x$ dijet cross-section in eA deeply in-elastic scattering (DIS) process for electron-ion collider (EIC) kinematics. We use the generalized High-Twist approach in our calculation, which do not perform twist expansion. Under small longitudinal momentum transfer approximation, the nuclear modified cross section can be approximately...
The cross section of hadronically decaying W/Z bosons at the high transverse momentum in proton proton collisions at 13 TeV measured by CMS will be presented. The W/Z bosons are identified using jets with the characteristic jet substructure. The measured results are compared with various MC predictions.
Measurements of W/Z-boson production in association with jets are an important test of perturbative QCD prediction and also yield information about the parton distribution functions of the proton. First, differential cross-sections for Z-boson production in association with jets using proton-proton collisions collected by the ATLAS experiment are presented. The data are compared to...
