Conveners
QCD & Heavy Ions
- Daniel Tapia Takaki (University of Kansas)
- Radja Boughezal (Argonne National Laboratory)
- Olga Evdokimov (University of Illinois at Chicago (US))
- Salvatore Rappoccio (The State University of New York SUNY (US))
QCD & Heavy Ions
- Salvatore Rappoccio (The State University of New York SUNY (US))
- Radja Boughezal (Argonne National Laboratory)
- Olga Evdokimov (University of Illinois at Chicago (US))
- Daniel Tapia Takaki (University of Kansas)
QCD & Heavy Ions
- Salvatore Rappoccio (The State University of New York SUNY (US))
- Radja Boughezal (Argonne National Laboratory)
- Olga Evdokimov (University of Illinois at Chicago (US))
- Daniel Tapia Takaki (University of Kansas)
QCD & Heavy Ions
- Salvatore Rappoccio (The State University of New York SUNY (US))
- Olga Evdokimov (University of Illinois at Chicago (US))
- Daniel Tapia Takaki (University of Kansas)
- Radja Boughezal (Argonne National Laboratory)
QCD & Heavy Ions
- Daniel Tapia Takaki (University of Kansas)
- Salvatore Rappoccio (The State University of New York SUNY (US))
- Olga Evdokimov (University of Illinois at Chicago (US))
- Radja Boughezal (Argonne National Laboratory)
QCD & Heavy Ions
- Daniel Tapia Takaki (University of Kansas)
- Olga Evdokimov (University of Illinois at Chicago (US))
- Radja Boughezal (Argonne National Laboratory)
- Salvatore Rappoccio (The State University of New York SUNY (US))
Description
parallel sessions
Collimated jets of hadrons serve as precision tests of the standard model and in particular QCD. For example, jets observables have been applied extensively to constrain parton distribution functions and to probe the hot and dense medium created in heavy-ion collisions, as well as to the search for physics beyond the standard model. In this talk, I will mainly focus on recent higher order...
The latest results from LHC on the vector boson (W or Z) production in association with jets will be discussed.
Collisions of ultra-relativistic heavy ions is the only known way of experimentally studying new form of QCD matter at high temperatures and energy densities. In such collisions, a state of deconfined quarks and gluons known as the quark-gluon plasma (QGP) is produced. Hard probes or partons from early-time interactions with large momentum transfer are produced prior to the formation of the...
The critical phenomena of strongly interacting matter are presented in the random fluctuation walk model. The phase transitions are considered in systems where the Critical Point (CP) is a distinct singular one existence of which is dictated by the dynamics of conformal symmetry breaking.
The physical approach to the effective CP is predicted through the influence fluctuations of...
The critical point in particle physics at high temperature is studied through the ideal gas of scalars, the dilatons, in the model that implies the spontaneous breaking of an approximate scale symmetry. The dynamical system of identical particles weakly interacting to each other is considered. We found the critical temperature as a function of a dilaton mass, and the fluctuation of particle...
One of the key signatures of collectivity in heavy-ion collisions is the appearance of a ridge structure over wide pseudorapidity interval. Recently it was also found in small collision systems such as proton-proton or proton-ion collisions which origin is still on debate. In this work, contributions from the geometry fluctuations in the initial-state in pp collisions to the ridge structure...
The observed thermalization in particle production at colliders,
usually inferred from the presence of the exponential component in
the transverse momentum distributions of produced particles and the
thermal abundances of the hadron yields, is proposed as due to quantum
entanglement inside the proton wave functions in the proton-proton
collisions. This presentation will show our...
The BESIII Experiment at the Beijing Electron Positron Collider (BEPC2) collected large data samples for electron-positron collisions with center-of-mass above 4 GeV. The analysis of these samples has resulted in a number of surprising discoveries, such as the discoveries of the electrically charged "Zc" structures, which, if resonant, cannot be accommodated in the traditional charm quark and...
I will review recent advances of tools that help improve the performance and analytic understanding of boosted object tagging and background mitigation. I will also discuss the fast developing fields of heavy ion jet substructure studies and machine learning applications at high energy colliders. In the end I will discuss a new class of collinear drop observables which allows systematic...
Theoretical calculations for jet substructure observables with accuracy beyond leading-logarithm have recently become available. Such well-understood observables provide novel probes of QCD in a new, collinear regime at the LHC. In this talk, measurements by the ATLAS, CMS, ALICE and LHCb collaborations of such jet substructure observables are presented. These measurements may be performed in...
In 2010 the proton charge radius was extracted for the first time from muonic hydrogen, a bound state of a muon and a proton. The value obtained was five standard deviations away from the regular hydrogen extraction. Taken at face value, this might be an indication of a new force in nature coupling to muons, but not to electrons. It also forces us to reexamine our understanding of the...
A sample of 1.3 billion J/psi events accumulated in the BESIII detector offers a unique opportunity to study light hadron spectroscopy and decays. In this presentation, recent BESIII results on the production of light hadrons will be highlighted, including amplitude analyses of J/psi radiative and hadronic decays for a variety of channels. Results on light meson decays will also be reported,...
Electromagnetic form factors of baryons provide fundamental information about their structure and dynamics and provide rigorous tests of non-perturbative QCD as well as phenomenological models. However, results in the time-like region have large uncertainties. Production cross sections and form factors of hyperons have only barely been explored. Based on 500 pb^-1 of data collected with the...
The sPHENIX experiment is a major upgrade to the PHENIX experiment that is currently under construction at Brookhaven National Laboratory. It will begin collecting pp, pA, and AA data in early 2023, enabling high statistics measurements of jet modification factors, upsilon suppression, and heavy flavor production. These measurements will complement those from the LHC experiments and help...
The sPHENIX experiment at Brookhaven is a second-generation RHIC
experiment designed to measure jets and the upsilon states in heavy
ion collisions with a combination of calorimetry and precision
tracking. A compact tungsten-scintillating fiber electromagnetic
calorimeter and a steel-scintillator hadronic calorimeter both read
out with silicon photomultipliers are are central to the...
Measurements of the beam-energy dependence of anisotropic flow can provide important constraints for initial state models and for precision extraction of the chemical potential ($\mu_B$) and temperature ($T$) dependence of the QCD matter, specific shear viscosity $\eta/s$. It has been predicted that the $\mu_B$ and $T$ dependence on $\eta/s$ could be sensitive to the critical endpoint (CEP) in...
The observation of multiparticle correlations in Heavy Ion collisions have long been related to collective behaviour in the formed medium. Recent results both at RHIC and LHC provide strong arguments for the formation of such medium in smaller systems.
RHIC has a broad program to study the physics of small systems by systematically varying its size and energy for a better understanding of the...
Entanglement and related subjects of quantum information science have become a hot topic in QCD. We review how and why this comes from a new point of view with fresh opportunities for experimental and theoretical investigation. The early history of QCD was dominated by makeshift models and case-by-case perturbative calculations. We now have new organizing principles and experimental...
Studies of small collision systems are essential to our understanding of the physics of strongly interacting matter at high temperatures. Proton-proton and proton-lead collisions with high particle multiplicities exhibit striking similarities to large nucleus-nucleus collisions, including apparent collective motion, quarkonium suppression, and similar hadrochemistry. An overview of recent...
In recent years the STAR Collaboration collected a large sample
of ultra-peripheral heavy-ion collisions. The photoproduction of
J/Psi vector mesons is sensitive to the gluon content of the target
nucleon or nucleus. We will present results from a statistically
large sample of J/Psi production in Au+Au collisions. A significant
result comes from the study of the pT distributions, which...
The $p_\perp$ dependence of the nuclear modification factor $R_{\rm AA}$ measured in XeXe and PbPb collisions at the LHC exhibits a universal shape, which can be very well reproduced in a simple energy loss model based on the BDMPS medium-induced gluon spectrum. The scaling is observed for various hadron species ($h^\pm$, $D$, $J/\psi$) in different centrality classes and at all colliding...
In relativistic heavy-ion collisions, correlations of particles with opposite quantum numbers provide insight into general charge creation mechanisms, the time scales of quark production, collective motion of the Quark Gluon Plasma (QGP), and re-scattering in the hadronic phase. The longitudinal and azimuthal widths of general charge balance functions for charged pion ($\pi^{\pm}$), kaon...
Measurements of heavy flavor hadrons and quarkonia in heavy ion collisions provide information about the in-medium color interaction inside the quark-gluon plasma (QGP), the high-density QCD medium created in heavy-ion collisions. Quarkonia, which are pairs of a heavy quark and an anti-quark, could be used to study the modification of color potential between the pairs. Heavy quarks are...
A rich set of quarkonia and heavy flavour result is observed by LHCb ALICE in pPb and pPbPb collisions collected at 5 and 8.16 TeV nucleon-nucleon centre-of-mass energies. In case of PbPb collisions heavy hadrons constitute unique probes for the hot and dense QCD medium produced in heavy-ion collisions: the Quark-Gluon Plasma. This talk presents production measurements of beauty hadrons and...
Recent phenomenological developments in the field of jet substructure have enabled new approaches to utilizing the internal energy density distributions of jets in physics analysis in ATLAS. In this poster, two applications of such substructure observables are presented. First, the performance of new jet substructure observables as inputs to multivariate techniques designed to identify jets...
Quantum entanglement has been proposed as the origin of thermalization in proton-proton collisions at the Large Hadron Collider (Phys. Rev. D98, 054007 (2018)). We present results of the entanglement entropy from charged-particle multiplicity data in nucleon-nucleon collisions at collider energies. These are compared with expected values from gluon distribution functions as well as...
