Quarkonium has been regarded as one of the golden probes to identify the phase transition from confined hadronic matter to the deconfined quark-gluon plasma (QGP) in heavy-ion collisions. Recent theoretical developments in the study of the J/ψ and ϒ families at the energies of Large Hadron Collider (LHC) are reviewed. In particular, the possible implications related to the production and...
In this talk we present our results on production of heavy quarkonia in $pA$ and $AA$ collisions in the color dipole approach. We analyze dynamics of quarkonium inside nuclear matter, and assess nuclear suppression due to shadowing and absorption, as well as consider novel multinucleon production mechanism. The contribution of this new mechanism explains why the measured nuclear effects remain...
ALICE is the LHC experiment dedicated to the study of high energy heavy-ion collisions, where the formation of a hot and dense strongly-interacting medium, a Quark-Gluon Plasma (QGP), is expected. Considerable theoretical and experimental efforts have been invested in the last 30 years to study the properties of the QGP. One of the signals of QGP formation is the suppression of quarkonia,...
The suppression of heavy quarkonia states in heavy-ion collisions is a phenomenon understood as a consequence of QGP formation in the hot, dense system formed in heavy-ion collisions at the LHC. In addition to hot matter effects in heavy-ion collisions , cold nuclear effects may also affect quarkonia production . Therefore, a full assessment requires detailed studies on the effects present in...
Charmonium states, such as the J/$\psi$ and $\psi$(2S) mesons, are excellent probes of the deconfined state of matter, the Quark-Gluon Plasma (QGP). The understanding of charmonia production in PbPb collisions requires the inclusion of many phenomena, such as dissociation in the QGP and statistical recombination, on top of cold nuclear matter effects (modifications of nPDFs, initial-state...
The LHCb experiment has the unique property to study heavy-ion interactions in the forward region (2 < η < 5), in a kinematic region complementary to the general purpose detectors. The detector has excellent capabilities for reconstructing quarkonia down to zero pT. Notably, it can separate the prompt and displaced components. In pPb collisions, both forward and backward rapidities are covered...
Charmonium states play an important role as probes of the phase transition between hadronic and deconfined matter. In high-energy nucleus-nucleus collisions, where the formation of a plasma of quarks and gluons is expected, the charmonium production yields are modified by mechanisms as color screening and/or (re)combination of $\rm{c}$ and $\bar{\rm{c}}$ quarks. However, charmonium production...
Open heavy flavour hadron production is studied in pPb collisions at sqrt{s_{NN}}= 5 and 8 TeV with the LHCb experiment. The detector has excellent capabilities for particle identification and for the reconstruction of charm and beauty hadrons down to zero pT. Both forward and backward rapidities are covered thanks to the possibility of beam reversal. Results include measurements of the...
In ultra-relativistic heavy-ion collisions, creation of a novel state of matter—the quark-gluon plasma (QGP)—is expected. Studying the properties of this medium of deconfined quarks and gluons has been a focus of high energy nuclear physics and poses a significant experimental challenge. Among various probes, quarkonium production is a crucial one since their production is expected to be...
Particles carrying heavy flavor are important probes of the properties of the Quark-Gluon Plasma (QGP) since they are produced in hard scattering during the earliest stages of nuclear collisions. In recent years, the PHENIX detector has collected data on p+p, p+Al, p+Au, He$^3$+Au, Cu+Au and Au+Au collisions at $\sqrt{s_{NN}}$=200GeV with the addition of silicon vertex detectors (VTX and...
The LHCb experiment, thanks to its System for Measuring Overlap with Gas (SMOG), has the unique capability to operate in a fixed target mode with the LHC beams.
Reactions of incident LHC proton beams on noble gas targets have been recorded by the LHCb experiment at a center-of-mass energy of 110 GeV and within the center-of-mass rapidity range -2.3 < y* < 0.2. Results on anti-proton production...
Low mass dielectron measurements in ultra-relativistic heavy-ion collisions
bring an important information on the properties of the hot and dense QCD medium and whole space-time evolution of the medium created in heavy-ion collisions.
Dielectrons in the mass range below 1 GeV/$c^2$, are from ordinary Dalitz and resonance decays of pseudoscalar and vector mesons. Dielectron invariant mass from...
The matter formed in central heavy-ion collisions at a few GeV per nucleon is commonly understood as resonance matter, a gas of nucleons and excited baryonic states with a substantial contribution from mesonic, mostly pionic excitations. Yet, in the initial phase of the reaction the system is compressed to beyond nuclear ground state density and hence substantial modifications of the hadron...
The microscopic description of heavy-ion reactions at low beam energies is
achieved within hadronic transport approaches. In this talk a new approach
SMASH (Simulating Many Accelerated Strongly-interacting Hadrons) is
introduced, verified, and applied to study particle production at $E_{Kin}$ =
0.4 - 2 A GeV in Au+Au collisions. First SMASH results for strangeness production are presented....
I will show how transport calculations, interfaced with a realistic hydrodynamic modeling of the background medium, allow one to provide predictions for momentum and angular distributions of heavy-flavour particles in high-energy nuclear collisions, to be compared eventually with experimental data (D/B-mesons and their decay products). The presence of a hot-deconfined medium (Quark-Gluon...
The LHC heavy-ion physics program aims at investigating the properties of the Quark-Gluon Plasma, QGP, formed in such collisions. Heavy quarks (charm and beauty) are regarded as efficient probes to study and characterize the QGP, as they are created on a very short time scale in initial hard processes and subsequently experience the entire system evolution interacting with the medium...
Charm quarks possess large masses and thus they are expected to be primarily produced at the initial stages of heavy-ion collisions. Hot and dense nuclear matter, usually referred to as the Quark-Gluon Plasma (QGP), can also be created in these collisions. Therefore, the QGP can be studied using charm quarks as penetrating probes via the in-medium energy loss, which is directly related to the...
We address the present theoretical challenge to have a self-consistent description of both the $R_{AA}(p_T)$
and the elliptic flow $v_2(p_T)$ at both RHIC and LHC.
We describe the heavy quarks dynamics in the quark-gluon plasma (QGP) by means of
a Boltzmann transport approach in which the non-perturbative interaction between
heavy quarks and light quark is described by means of a quasi...
Heavy quarks (charm and beauty) are probes of the Quark-Gluon Plasma (QGP) formed in high-energy nuclear collisions. They are produced in hard partonic scattering processes occurring in the initial stage of the collisions, propagate through the medium, and interact with its constituents, thus probing the entire evolution of the system.
The heavy-flavour production in proton-nucleus...
Strangeness production at high multiplicity gives indications on the transverse size fluctuactions in AA,pA and pp. In particular the universal behavior
of strange particle hadronization in small and large systems can be tested for the specific particle species, for different centralities and for large fluctuation of the transverse size
in pA and pp by using the recent ALICE data. The...
We present new ALICE results on the production of strange and multi-strange hadrons in Pb-Pb collisions at the top LHC energy of $\sqrt{s_{\rm NN}}$ = 5.02 TeV.
Strangeness production measurements are powerful tools for the study of the thermal properties of the deconfined state of QCD matter, the Quark-Gluon Plasma.
Thanks to its unique tracking and PID capabilities, ALICE is able to measure...
In this talk, the centrality dependence of the $p_{\rm T}$ spectra of unidentified charged hadrons as well as of charged pions, kaons, (anti)protons and resonances in Pb-Pb collisions at the unprecedented energy of $\sqrt{s_{\rm{NN}}} = 5.02$ are presented. The $p_{\rm T}$-integrated particle yields are compared to predictions from thermal-statistical models and the evolution of the proton to...
New results on transverse momentum spectra of identified charged hadrons in proton-proton collisions at sqrt(s) = 13 TeV are presented using CMS detector at the LHC. Charged pions, kaons, and protons in the transverse-momentum range pT = 0.1-1.7 GeV/c and for laboratory rapidities |y| < 1 are identified via their energy loss in the CMS silicon tracker. The pT spectra and integrated yields are...
At the end of 2015 the ALICE experiment at the LHC has recorded Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV, that complement the dataset from Run 1. Both datasets contain a variety of (anti-)(hyper-)nuclei produced in the collisions, namely (anti-)deuteron, (anti-)triton, (anti-)helium-3, (anti-)alpha and (anti-)hypertriton. Furthermore, the large high quality data sample of pp...
Jet quenching in the hot, dense medium formed in Au+Au collisions leads to the suppression of high $p_T$ particles which can be studied with the measurement of the leading hadrons, like $\pi_0$. They can be used to investigate the mechanism of energy loss of partons in a QGP when varying the collision geometry.
Asymmetric Cu+Au collisions provide a system with similar energy density but...
NA61/SHINE is a fixed target experiment at the CERN Super-Proton-Synchrotron. The main goals of the experiment are to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. In order to reach these goals, a study of hadron production properties is performed in nucleus-nucleus, proton-proton and proton-nucleus interactions as a function...
The intense photon fluxes of relativistic nuclei provide a possibility
to study photonuclear and two-photon interactions in ultra-peripheral collisions (UPC)
where the nuclei do not overlap and no strong nuclear interactions occur.
The study of such collisions provides information about the initial state of nuclei (nPDF).
Exclusive $J/\psi$ production in UPC which is sensitive to the...
ATLAS, CMS and ALICE experiments have measured flow-like signatures in p+p collisions at 5.02 and 13 TeV that are reminiscent of those found in heavy-ion collisions. These signatures can naturally be explained as originating from tiny droplets of QCD plasma expanding hydrodynamically. I will review the applicability of hydrodynamics to plasma droplets below the femtometer scale and discuss...
The measurement of flow harmonics of charged particles from v_2 to v_7 in Pb+Pb collisions in the wide range of transverse momentum and pseudorapidity provides not only a way to study the initial state of the nuclear collisions and soft particle collective dynamics, but also provides insight into jet quenching via the measurement of flow harmonics at high transverse momenta. The longitudinal...
The $v_{2}$ and $v_{3}$ anisotropy harmonics of charged particles and prompt $D^{0}$ meson are measured at |y|$\le$ 1 as a function of transverse momentum ($p_{T}$) and centrality classes in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV collected with the CMS detector. The results indicate that the charm quarks interact strongly with the QGP medium. Comparisons between theoretical predictions...
The two-wave quark production scenario can be investigated experimentally by measurements of balance functions of identified particle pairs [1]. By studying the balance functions of several hadronic species, one can gain insight into the chemical evolution of the QGP and radial flow. In a picture of early hadronization, pairs of particles and anti-particles (created at the same spacetime...
In nucleus-nucleus collisions, the Quark-Gluon Plasma behaves like a perfect fluid and the azimuthal anisotropy of the observed particle final-state distributions reflects its properties. This anisotropic flow, arising mainly from initial-state geometry and its fluctuations, highlights the collective behavior of the particles produced in the collision. It is well-described by hydrodynamics and...
The angular correlation function (CF) refers to the correlation of particles in the relative pseudorapidity and relative azimuthal angle. It is used to study strongly interacting matter properties at relativistic energies. Recent results from the ALICE experiment at LHC show unexpected structures of CF in the proton-proton and antiproton-antiproton correlations. Also results from the STAR...
The exploration of the QCD phase diagram is the most important task of present heavy ion experiments. In particular, we want to study the phase transition from hadronic to partonic matter and look for the critical point (CP) of strongly interacting matter. Fluctuations and correlations in kinematic characteristics and particle yields may help to locate the CP (in analogy to enlarged...
The emergence of the Chiral Magnetic Effect (CME) and the related anomalous current is investigated using the real time Dirac-Heisenberg-Wigner formalism. This method is widely used for describing strong field physics and QED vacuum tunneling phenomena as well as pair-production in heavy-ion collisions. We extend earlier investigations of the CME in constant flux tube configuration by...
I present our work on simulating the Glasma in the early stages of heavy ion collisions in a non-boost-invariant setting. Our simulation is based on the colored particle-in-cell method, which is used to numerically solve the Yang-Mills equations in 3+1 dimensions. This approach allows us to describe colliding nuclei with finite longitudinal width by extending the McLerran-Venugopalan model to...
In the idealized high-energy limit of heavy-ion collisions, the system right after collisions is described as an over-occupied gluonic plasma expanding in the longitudinal direction, which is called Glasma. The understanding of the quark dynamics in such a pre-equilibrium state is of prime importance as it has a direct connection to electromagnetic probes such as photons. We report on a...
We show the results of our recent global analysis of EPPS16 NLO nuclear parton distribution functions (nPDFs). For the first time, dijet and heavy gauge boson production data from LHC proton–lead collisions have been included in a global fit. Especially, the CMS dijets play an important role in constraining the nuclear effects in gluon distributions. With the inclusion of also neutrino–nucleus...
Electroweak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus are sensitive to the nuclear modification of parton distribution functions (nPDFs). The ATLAS detector, optimised to search for new physics in proton-proton interactions, is well equipped to measure photons, W and Z bosons in the high occupancy environment produced in heavy-ion...
Beams of relativistic heavy ions accompanied by a large flux of equivalent photons, and photon-induced reactions are the dominant interaction mechanism in heavy-ion collisions when the colliding nuclei have transverse separation larger that the nuclear diameter. In these ultra-peripheral collisions (UPC) the photon can provide a clean probe of the partonic structure of the nucleus analogous...
I will review the recent developments in the understanding of the dynamics of jets that propagate through QGP with particular emphasis on jet substructure. I will argue that substructure observables provide a novel direction in quenching studies.
High energy collisions of heavy nuclei permit the study of nuclear matter at temperatures and energy densities. Under these conditions the fundamental theory for strong interactions, QCD, predicts a phase transition to a plasma of quarks and gluons. This matter, called a Quark Gluon Plasma (QGP), has been studied experimentally for the last decade and has been observed to be a strongly...
In relativistic heavy-ion collisions, a hot medium with a high density of unscreened colour charges is produced. Jets are produced at the early stages of this collision and are known to become attenuated as they propagate through the hot matter. One manifestation of this energy loss is a lower yield of jets emerging from the medium than expected in the absence of medium effects. Another...
We study the gluon distribution produced via successive medium-induced branchings
by an energetic jet propagating through a weakly-coupled quark-gluon plasma. We show that
under suitable approximations, the jet evolution is a Markovian stochastic process,
which is exactly solvable. For this process, we construct exact analytic solutions
for all the n-point correlation functions describing the...
Understanding the energy loss of strongly interacting particles is of utmost importance for studying the quark‐gluon plasma (QGP). This very hot and dense state of matter is created during heavy‐ion collisions, like the ones performed at the LHC. As the lifetime of the QGP is very brief, special probes are necessary to study it. One of them consists in focusing on the energy loss of energetic...
We present the con?guration in which a quark-antiquark pair with a fi?xed opening
angle emits a hard gluon inside a medium, and an additional very soft emission afterwards (double antenna). We discuss the coherence effects in terms of the survival probability, which describes the interaction of the quark-antiquark-gluon system with the medium. We generalize previous studies of the antenna...
We report on double inclusive jet production in Pb-Pb collision within newly constructed framework combining High Energy Factorization with mechanism for energy loss in Quark Gluon Plasma. The framework allows for exact treatment of kinematics of colliding partons and therefore to increase accuracy in studies of energy loss of jets in quark gluon plasma. Furthermore the chosen configuration of...
We present results on the measurement of very forward jets in p-Pb data with the CASTOR calorimeter in the CMS experiment at 5 TeV.
The study of the azimuthal correlation with $\pi^0$ offers a powerful way to investigate the properties of strongly-interacting matter created in ultra-relativistic heavy-ion collisions.
In this talk, we present the measurement of two-particle correlations of $\pi^0$ trigger particles with associated charged particles versus azimuthal angle difference ($\Delta\varphi$) in pp and central Pb–Pb...
This presentation will review the projected accelerator performance and the physics opportunities for a heavy-ion programme at FCC-hh [1]. In addition, the status of the FCC-hh detector design studies will be discussed.
The FCC-hh Design Study will assess the feasibility and potential of a hadron collider with a centre-of-mass of 100 TeV for pp collisions.
Operating FCC-hh with heavy-ion...
The Large Hadron-electron Collider LHeC and the Future Circular Collider in electron-hadron mode FCC-eh will provide unique electron-lead collisions with center-of-mass energies in the range 0.8-2.2 TeV, and instantaneous luminosities around $10^{33}$ cm$^{-2}$s$^{-1}$ per nucleon that will result in luminous data samples of typically 10 fb$^{-1}$ per nucleon. In this talk, we illustrate the...
The Compressed Baryonic Matter (CBM) experiment at the Facility for Antiproton and Ion Research (FAIR) will explore the phase diagram of strongly interacting matter in the regions of highest net-baryonic densities and moderate temperatures. The high beam intensities that will be delivered from FAIR's SIS-100 heavy-ion synchrotron and possible upgrades will enable addressing several physics...
The main scientific goal of the NICA heavy-ion physics program
at JINR will be an experimental investigation of the properties of
nuclear matter under extreme conditions. A comprehensive scan
of the QCD phase diagram in the region of maximum baryon density
will be performed at NICA with ion beam species ranging from protons
to gold nuclei. Systematic measurements of the production of...
