We extend the derivation of second-order relativistic viscous hydrodynamics to incorporate the effects of baryon current, a non-vanishing chemical potential, and a realistic equation of state. Starting from a microscopic quantum theory, we build a quasiparticle approximation to describe the evolution of hydrodynamic degrees of freedom, highlighting its connection to the Wigner formalism. We...
The QCD phase diagram is expected to be affected by the system size for small volumes. The most common strategy to study these effects in theoretical models is to consider the constraints in momentum space imposed by the finite spatial extension. The different approximations in the various models show similar behavior in some aspects but very different details for the phase diagram and the...
Although it is conjectured that a phase transition from hadronic to deconfined quark matter is possible in the ultrahigh density environment in Neutron Stars, the nature of such a transition is still unknown. Depending on whether there is a sharp or slow phase transition, one may expect a third family of stable compact stars or “twin stars” to appear, with the same mass but different radii...
The density functional theory (DFT) is one of physics's most popular methods for simulating systems' microscopic properties. It allows for studies of many-body Fermi systems' static, dynamic, and thermodynamic properties in a unified framework while keeping the numerical cost at the same level as the mean-field approach. The development of (super)computing techniques in the last decade allows...
The existence and location of the QCD critical point are key topics of experimental and theoretical research in heavy ion collisions. The NA61/SHINE experiment at CERN SPS provides valuable data to study how different correlation and fluctuation observables depend on collision energy and the size of colliding nuclei.
This contribution will summarize the status of NA61/SHINE critical point...
We investigate the evolution of charm quarks in hot QCD matter employing the effective quasiparticle approach. In this framework, the QGP comprises the quasi-quarks and -gluons with the dynamically generated masses linked to the lattice QCD equation of state. Using the kinetic rate equation, we study the production of the $(c\bar{c})$ pairs for two distinct scenarios of the QGP evolution: the...
One of the most effective techniques for investigating the mechanism of baryon
production is the study of angular correlations between two particles. Angular correlations represent a convolution of various physical processes, such as
mini-jets, Bose-Einstein quantum statistics, conservation of momentum, resonances, and other phenomena that contribute to the unique behavior observed
for...
We study the effect of magnetic field on particle ratios and charge fluctuations in hadron resonance gas. We argue that the big change in the pion to proton ratio is due to ill-defined description of higher-spin states, and that because of detailed balance, neutral resonances must be affected by the field too. The calculated fluctuations of conserved charges are likewise suspicious and must be...
The NA61/SHINE collaboration recently reported an excess of charged versus neutral kaons that signals an unexpectedly large breaking of the isospin symmetry. Similar excesses were also present in previous experiments, but with larger errors. Models for hadron productions in heavy ion collisions systematically underestimate the measured charge-to-neutral kaon ratio. In this talk, we report on...
The ϕ meson is a resonance particle and the lightest particle with hidden strangeness, containing both s and s̅ quarks. Strangeness enhancement is considered to be related to Quark-Gluon Plasma formation, making the ϕ meson a valuable probe due to its "double strangeness" in a partonic and zero net strangeness in a hadronic medium. Previous studies, such as EPJC 80 (2020) 199, demonstrated...
We present the first solution of (3+1)-dimensional ideal spin hydrodynamics embedded within a realistic hydrodynamic background. Using a suitable choice of initial conditions, we achieve a simultaneous description of bulk and polarization observables, successfully reproducing the correct sign of longitudinal polarization. The findings point to delayed spin thermalization, implying that...
The azimuthal anisotropy of the final-state particles in nuclear-nuclear collisions arises from the geometry of the quark-gluon plasma fireball. In this talk, I will present flow coefficients $v_2$ and $v_3$ of charged particles measured in the Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV recorded by the ATLAS experiment in 2018. This measurement uses the scalar product and...
Compressed Baryonic Matter (CBM) is a fixed-target experiment that is part of the Facility for Antiproton and Ion Research (FAIR) that currently is under construction. Its primary objective is to investigate the phase diagram of strongly interacting matter (QCD) under conditions of high net-baryon density and moderate temperature. This will be achieved by studying heavy-ion and hadron...
The experimental particle yields (36 multiplicities in total) from pp interactions around $\sqrt{s} \sim $ 10 GeV are reasonably described [1] within statistical hadronization model ThermalFist [2]. The volume for strangeness was used as an additional free parameter, essential for the quality of the reproduction of experimental results (-3$\pm$17 \% average relative difference). Among the...
Relativistic heavy-ion collisions provide a way to study the properties of nuclear matter under extreme conditions. One method for investigating the characteristics of bulk matter is the femtoscopy technique. This method allows for the extraction of the space-time characteristics of the expanding fireball produced in heavy-ion collisions and to collect information on the interaction between...
The availability of multidimensional and multivariate data on femtoscopic radii in heavy-ion collisions (HIC) is marginal at centre-of-mass energies of a few GeV. It impairs the development of theoretical models that describe the particle dynamics of HIC at those energies. The currently available femtoscopic radii were primarily extracted from the measurement of identically charged pions,...
The study of femtoscopic correlations between photon pairs, although challenging from an experimental standpoint, can serve as a complementary approach to traditional hadron femtoscopy. Owing to the penetrative nature of photons, which are unaffected by strong or electromagnetic interactions, such measurements can be used to probe the early stages of heavy-ion collisions, prior to freeze-out....
The second quantum revolution is opening new avenues for development. The three main pillars which sustain the current effort are quantum telecommunication, quantum computing and quantum sensing. The three fields are tightly connected to each other and advances in any of them move the boundaries of the whole field. On an international scale, there is an ongoing effort to bridge the...
Identifying products of ultrarelativistic collisions, such as the ones delivered by the LHC and RHIC, is one of the crucial objectives of experiments such as ALICE and STAR, which are specifically dedicated to this task with a number of detectors allowing particle identification (PID) over a broad momentum range.
Recently, as a team of physicists and computer scientists at the Warsaw...
Measurements of top-quark pairs in heavy-ion collisions are expected to provide novel probes of nuclear parton distribution functions as well as to bring unique information about the time evolution of strongly interacting matter. We report the observation of top-quark pair production in proton-lead collisions at the centre-of-mass energy of 8.16 TeV in the ATLAS experiment at the LHC....
Jets of strongly interacting particles represent a useful means to examine particle interactions within the hot and dense medium of a quark gluon plasma (QGP)
that can be recreated by ultrarelativistic heavy ion collisions.
I present a Monte-Carlo algorithm, where jets evolve in the medium via the jet-medium interactions of scatterings and medium induced radiations as well
as vacuum like...
Based on a generalized Beth-Uhlenbeck approach to thermodynamics of QCD we explain why the abundances of hadrons produced in ultrarelativistic heavy-ion collisions are well described by the hadron resonance gas (HRG) model with a sudden chemical freeze-out at a well-defined hadronization temperature despite the fact that state of the art results of lattice QCD indicate a smooth chiral...
We present a differential study of $\Lambda$ hyperon polarization in central Au+Au collisions at $\sqrt{s_{NN}} = 7.7$ GeV, employing the microscopic transport model UrQMD in conjunction with the statistical hadron-resonance gas model. The resulting thermal vorticity configuration effectively manifests as the formation of two vortex rings in the forward and backward rapidity regions. We show...
We analyze an effective statistical model for nuclear matter based on a virial-type expansion for the internal energy. In the thermodynamic limit, the order parameter satisfies an integrable partial differential equation, whose solution is a family of equations of state unveiling nuclear and quark-hadron phase transitions through gradient catastrophe and shock formation. We further demonstrate...
The matter produced in an ultra-relativistic heavy-ion collision, dubbed as the QGP, posses a temperature $10^5$ times that of Sun's core and survives for a very short time ($10^{-22}$ s), producing thousands of particles which exhibit collective motion described by some global observables, e.g. charged particle multiplicity($N_{ch}$), mean transverse momentum per particle ($[p_T]$), harmonic...
This paper presents a comparative analysis of experimental results from heavy-ion collision experiments conducted at two of the world's leading research facilities: the RHIC (Relativistic Heavy Ion Collider) in the United States and the LHC (Large Hadron Collider) in Switzerland. These studies aim to investigate the properties of strongly interacting matter under extreme temperatures and...
Femtoscopic correlations allow us to probe into the space-time structure of the source of particle emission, which appears after a heavy-ion collision. Most analyses focus on collisions of heavier elements or high energies (or both) as it allows for the usage of so-called smoothness approximation. In this work, the applicability of this approximation will be tested, as it does not work at low...
This paper explores the critical role of strange and heavy hadrons in studying the phase diagram of strongly interacting matter. Strange particles, such as kaons, hyperons, and multistrange baryons, are sensitive probes of the dense and hot environment created in heavy-ion collisions. Due to their unique production mechanisms and short lifetimes, strange hadrons provide crucial insights into...
