Conveners
QCD with Heavy Flavors and Hadronic Final States: Day2-morning-1
- Ronan McNulty (University College Dublin (IE))
- Daniel Greenwald (Technische Universität München)
QCD with Heavy Flavors and Hadronic Final States: Day2-morning-2
- Ronan McNulty (University College Dublin (IE))
- Daniel Greenwald (Technische Universität München)
QCD with Heavy Flavors and Hadronic Final States: Day2-afternoon-1
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day2-afternoon-2
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day3-morning-1
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day3-morning-2
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day3-afternoon-1
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day3-afternoon-2
- There are no conveners in this block
QCD with Heavy Flavors and Hadronic Final States: Day4-morning-1
- There are no conveners in this block
The Pierre Auger Observatory is the world's largest detector for the observation of ultra high energy cosmic rays (UHECRs). We use a series of fluorescence telescopes and a particle array at the surface to obtain detailed measurements of the energy spectrum, mass composition and arrival directions of primary cosmic rays with energies above 10^17 eV with accuracy not attainable until now. ...
The LHCb collaboration has measured cross sections for production of two charmed-particles in pp collisions. These include opposite-sign and same-sign open-charm pair production where the former is dominantly produced in a single parton scattering (SPS) but the latter can be used to study double parton scattering (DPS). In this work we have set up a NLO pQCD framework to calculate double...
Measurements of W/Z-boson production in association with jets provide important tests 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 at √s = 8 TeV are presented. The data are...
Measurements of electroweak bosons produced in Pb+Pb collisions as well as photon and jet production in small collision systems are of great interest to understanding the partonic structure of heavy nuclei, and serve as a constraint on the initial state in large collision systems. These channels are sensitive to a broad set of physics effects such as the modification of the parton densities in...
I present new theoretical results at approximate N$^3$LO for double-differential distributions in top-quark transverse momentum and rapidity. The higher-order corrections are from NNLL resummation of soft-gluon contributions. The corrections are very significant and they reduce theoretical uncertainties. The theoretical predictions are in very good agreement with recent LHC data.
Comprehensive measurements of differential cross-sections of top-quark-antiquark pair-production are presented. The measurements are performed in the lepton+jets and the all-hadronic channels which allow for reconstruction of the top-quark and top-quark-pair kinematic distributions. The two channels are complementary in terms of range and resolution for several variables. Both measurements use...
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 mainly comes from top-quark-antiquark production in association with heavy flavor jets. In this presentation, two analyses are...
We present NLOPS matched predictions for $pp \to \ell \nu_\ell j j b \bar b$ at $\alpha^4 \alpha_s^2$ within the POWHEG BOX RES framework. This process is dominated by top-pair production and decay in the semileptonic channel. The hadronic decay of the W-boson is considered in an approximation that allows for consistent inclusion of the contributions from $t\bar t$ and $Wt$ single-top...
Latest 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...
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 will be discussed.
Heavy quarkonium production provides valuable grounds to explore 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...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial
upgrade of the B factory facility at KEK in Tsukuba, Japan. It aims to record a factor of 50 times
more data than its predecessor. The experiment completed a commissioning run in 2018, and
began full operation in early 2019. Belle II is uniquely capable of studying the so-called "XYZ"
particles:...
The discovery of pentaquark candidates in Lb->JpsipK decays at LHCb has opened a new field in exotic spectroscopy. Analysis of full dataset of b-hadron decays collected during Run I and II provides opportunities to examine the established states with better precision, their investigation in new decay modes and for searches of new exotic hadron candidates. Recent results of these studies will...
A statistical combination of the search results for the X(5568) resonance decaying into $B_s π$ is reported, based on published results from the ATLAS, CMS, CDF and LHCb Collaborations.
A narrow structure in the invariant mass distribution of $B^0_s π^±$ has been observed by the D0 Collaboration with a mass value of 5568 MeV but not confirmed by any of the latest searches from the other...
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 measurements from ATLAS on quarkonium production, including associated production, and recent results from heavy flavour production. In addition, recent...
The heavy quarkonium together with b-hadrons provide a rich material for testing effective theories of strong interaction via production, decay and spectroscopy studies. This talk presents recent progress on these studies at LHCb obtained using the full dataset collected during runs I and II of the LHC.
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 FCNC-suppressed neutral B-mesons decays.
This talk will focus on the latest results from ATLAS, such as rare processes: B^0_s → mu mu and B^0 → mu mu; and CPV in Bs to Jpsi Phi, where Standard Model predicts the CP violating phase,...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure...
PHENIX has made a comprehensive measurement of low p$_\mathrm{T}$ direct photon yield in Au+Au collisions at 200 GeV that show both a large yield and a large azimuthal anisotropy produced. The mechanism for such simultaneous large production is not well understood yet.
Recently the PHENIX collaboration has improved on those measurements by using the Au+Au data collected in 2014 which...
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 to start the exploration of such processes.
We discuss 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,...
A. SHABETAI (for the ALICE Collaboration)
Highly energetic point-like partons produced in a hard scattering will lead to a parton shower which will be fragmenting into a hadronic spray of particles called a jet. The partonic stage of such shower can be calculated from first principles using the QCD factorisation theorem. Jet substructure observables, such as jet fragmentation functions...
Heavy flavor production is an ideal tool to study the properties of the QCD medium created at the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC). The kinematic coverage and production mechanisms of the heavy flavor are different between RHIC and LHC. The PHENIX experiment has a comprehensive physics program which studies open heavy flavor and quarkonium production...
I will present a new class of jet/event substructure observable called collinear drop and its use in the search for novel signatures of jet modifications and medium responses. I will demonstrate using Monte Carlo simulations generated with Jewel how underlying jet-medium interactions can be systematically examined using collinear-drop observables. I will also give analytic insights on the...
Measurements of the internal properties of jets allow QCD to be studied at a new regime at a hadron collider. In this talk, we discuss recent measurements of jet substructure and jet fragmentation that 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...
We study the angle between i) the standard jet axis, ii) the axis of a jet
which has been groomed using soft drop, with reduced sensitivity to soft radiation, iii) the
jet axis obtained with the winner-take-all recombination scheme, which is insensitive to
soft radiation at leading power. We calculate the distributions for these angles at next-to-leading logarithmic accuracy, including...
Jet substructure represents a cornerstone in current BSM searches at the LHC. Further, it is instrumental in the on-going endeavor to pinpoint the effect of a hot, thermal medium, namely the QGP, on QCD dynamics. In this talk, based on [1], I will present a new set of jet substructure observables and an associated grooming technique rooted on identifying the hardest splitting in an angular...
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...
The LHCb experiment at the Large Hadron Collider (LHC) at CERN is suited for studying various aspects of the theory of strong interaction, Quantum Chromo-Dynamics. One area of active research is to understand how hadrons are formed from scattered quarks and gluons, collectively referred to as partons, in energetic proton-proton collisions. The hadronization process is a non-perturbative...
We present a theoretical formalism and associated results for soft-gluon resummation for $2 \rightarrow n$ processes in single-particle-inclusive kinematics.
The factorization of short-distance partonic cross sections from universal nonperturbatively-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 energetic...
The status of the three-loop heavy-flavor corrections to unpolarized and polarized deep-inelastic scattering is reviewed. We discuss the analytic results on the single and two-mass corrections and also outline the consequences for the variable flavor number scheme in high energy hadronic scattering and heavy quark distribution functions.
Abstract In this talk we present our theoretical results for the multiplicity dependence of $J/\psi$ production and compare it with recent experimental data from STAR and ALICE collaborations. We argue that a rapidly growing multiplicity dependence presents a strong evidence in favor of multigluon fusion mechanisms of the quarkonia states. We demonstrate that the experimentally observed...
The confinement of quarks and gluons, the building blocks of all visible matter, is perhaps the ultimate example of quantum entanglement. Inside nucleons they are not just correlated, they do not even exist as isolated states. However, in the parton model formulated by Bjorken, Feynman, and Gribov, the partons are viewed by an external hard probe as independent when the nucleon is boosted to...
The production of prompt isolated photons and jets at hadron colliders provides stringent tests of perturbative QCD and can be used to evaluate the probability density functions of partons in the proton. In this talk, we present the measurements of the isolated-photon plus two jets and the inclusive isolated-photons cross sections, both measured using proton-proton collision data collected by...
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-$\chi$ 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,...
In order to perform precise Standard Model measurements or to search for new physics phenomena at hadron colliders, it is important to have a good understanding of not only the short-distance hard scattering process, but also of the accompanying activity – collectively termed the underlying event. In this talk we present a study of the underlying event activity in events containing a Z-boson...
Two-particle azimuthal correlations have been measured in neutral current deep inelastic ep scattering with virtuality $Q^2 > 5$ GeV$^2$ at a centre-of-mass energy $\sqrt{s}=318$ GeV recorded with the ZEUS detector at HERA. The correlations of charged particles have been measured in the range of laboratory pseudorapidity $-1.5 < \eta < 2$ and transverse momentum $0.1 < p_T < 5$ GeV and event...
The study of hadron production and anisotropic flow are key to the understanding of the medium produced in heavy ion collisions and its event-by-event fluctuations. Recent results in small systems both at RHIC and LHC support the formation of such medium at those scales.
PHENIX has measured the spectra of charged and identified particles for several small systems and at various energies, as...
ATLAS measurements of flow harmonics ($v_n$) and their fluctuations in Pb+Pb and Xe+Xe collisions covering a wide range of transverse momenta, pseudorapidity and collision centrality are presented. The measurements are performed using data from Xe+Xe collisions at 5.44 TeV and Pb+Pb collisions at 2.76 and 5.02 TeV. The $v_{n}$ are measured up to $n=6$ using the two-particle correlations,...
This talk presents multiple recent ATLAS measurements form the ATLAS collaboration that study features of the azimuthal distributions for charged particles in $pp$ and $p$+Pb collisions. The measurement of the azimuthal anisotropy of charged hadrons in $p$+Pb collisions up to a transverse momentum of 50 GeV are presented. In A+A collisions non-zero flow coefficients at high-$p_{T}$ are...
