We present a Bayesian analysis of equation of state (EOS) constraints using recent observational data for masses, radii and tidal deformability of pulsars and a class of hybrid neutron star EOS with color superconducting quark matter on the basis of a recently developed nonlocal chiral quark model.
The nuclear matter phase is described within a relativistic density functional model of the...
In non-central heavy-ion collisions, large orbital angular momentum and strong vorticity fields are produced and predicted to polarize quark spins. Unexpectedly large global spin alignment ($\rho_{00}$) values for ${\phi}$(1020) mesons have been reported in the first phase of the RHIC Beam Energy Scan (BES-I) in Au+Au collisions [1]. These values exceed conventional expectations based on...
Results are shown from a one-dimensional femtoscopic analysis of $\text{K}^{0}_{\text{S}}\text{K}^{0}_{\text{S}}$ from Pb–Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV. The centrality and transverse momentum in the pair reference frame $k_{\rm T}$ dependence is analyzed. These results are compared to previous results from ALICE at 2.76 TeV (J. Adams et al., 2015, Physical Review C 92,...
A major source of uncertainty in the study of heavy-ion collision originates from the early time dynamics which includes initial state and pre-equilibrium dynamics. Among these, pre-equilibrium dynamics link the initial particle production in classical field simulations to subsequent hydrodynamic evolution and a (3+1)D framework is necessary to achieve a complete description of the dynamics....
The quark-gluon plasmas produced in non-central relativistic heavy-ion collisions can have large vorticities, leading to spin polarization in a manner analogous to the Barnett effect. Such spin polarization has been observed in $\Lambda$ hyperons [1], spurring rapid development in the area of spin physics in heavy-ion collisions. However, tension remains between experimental data and theories...
Although calculations of QCD thermodynamics from first-principle lattice simulations are limited to zero net-density due to the fermion sign problem, it is possible to extend the equation of state (EoS) to finite values of the $B$, $Q$, $S$ chemical potentials via expansions around zero chemical potentials. Taylor expansion around $μ_i = 0$ with $i = B, Q, S$ enables to cover with confidence...
Leveraging on the excellent performance of the LHCb spectrometer and on the flexibility of its online reconstruction, new methods for the identification of deuteron and helium nuclei have been developed at LHCb. These innovative methods, based on LHCb time of flight capabilities and on energy loss discrimination in the LHCb detectors, open a new window of possible measurements at LHCb. A...
The location of critical-point as per quantum chromodynamics (QCD) and the nature of phase transition is the subject of both theoretical and experimental studies. It is observed that local density fluctuations are directly related to the critical behaviour in QCD. As the system approaches phase transition, there is a divergence of the correlation length. The system becomes scale-invariant with...
The simultaneous description of jet observables such as the nuclear modification factor $R_{\rm AA}$ and elliptic flow $v_2$ as a function of transverse momentum is a challenge both in large and small colliding systems. For large systems there is the complication of the hydrodynamic background and response, whereas in small systems so far no measurable jet quenching could be identified. This...
Measurements of Balance Functions were proposed more than two decades ago to probe the evolution of particle production in relativistic heavy ion collisions by Pratt et al.. It subsequently emerged that Balance Functions can also be used to probe the susceptibility of QCD matter near the phase transition and the light quark diffusivity. I will briefly review the theoretical work done in the...
A central ingredient in the description of QCD jets in the quark-gluon plasma is the gluon emission probability off a quark leg. Despite its critical importance, this object has only been computed under a set of approximations concerning both the kinematics of the process and the description of the medium. In this talk we will present new results that go significantly beyond the...
This study reports measurements of event-by-event fluctuations in mean transverse momentum ($\langle p_{\rm T} \rangle$) using the integral correlator $\langle \Delta p_{\rm T} \Delta p_{\rm T}\rangle$ and the skewness of the event-wise $\langle p_{\rm T} \rangle$ distribution in pp collisions at $\sqrt{s}=13$ TeV. These measurements are conducted with the Monte Carlo event generators PYTHIA8...
I discuss the fluctuations of the net-baryon number near the liquid-gas and chiral phase transitions. I use the parity doublet model to investigate the qualitative properties and systematics of the first- to fourth-order cumulants and their ratios. I show that the fluctuations of the positive-parity (e.g. protons) and negative-parity baryons do not qualitatively reflect the fluctuations of the...
In recent years, CMOS silicon pixel detectors have seen significant advancements and widespread usage across various physics fields, allowing for significant improvements in particle detection technologies. One relevant example is the ALPIDE chip, which is a CMOS Monolithic Active Pixel Sensor developed for the upgrade of the Inner Tracking System of the ALICE experiment at the LHC.
On top of...
In ultra-relativistic heavy-ion collisions, the Lorentz-contracted electromagnetic fields of the ions generate intense quasi-real photon fluxes. These lead to photon-induced interactions that have been observed in ultra-peripheral collisions (UPCs), such as vector meson and lepton-pair production. The high photon flux also enables the occurrence of multiple photon-induced processes in a single...
We investigate the effects of including strong charge parity violating effects through axion field on the structure and the oscillation modes of the neutron stars with the possibility of a quark matter core. The effects of axions in quark matter is described through a t Hooft determinant interaction in the flavor space within the ambit of a three flavor Nambu--Jona-Lasinio model. The presence...
In recent years, there has been a surge of interest in the electromagnetic processes underlying dilepton production in two-photon scattering, particularly in the context of Ultra-Peripheral heavy ion Collisions (UPC). Our research delves into this phenomenon by examining the azimuthal asymmetry that arises from the multiple interactions of energetic leptons with the medium in UPC...
The production of beauty quarks can be calculated within perturbative Quantum Chromodynamics (pQCD) due to their large mass, allowing for precise comparisons with experimental results. Beauty-quark tagged jets (b-jets) allow to experimentally reconstruct the kinematics of the scattered beauty quark and probe its subsequent shower evolution.
Nonetheless, traditional b-jet tagging algorithms...
In high energy nuclear collisions, the majority of the charm and beauty quark production occurs via perturbative hard scattering on a short timescales and undergoes transport through a medium (which depends on the system), experiencing drag, diffusion, scattering, or recombination into bound states. Investigating these processes requires methods sensitive to both the production cross section...
Light nuclei production is expected to be sensitive to a QCD phase transition at large net-baryon densities which are accessible in heavy-ion collisions. I will present results of a study with the UrQMD transport model supplied with a density dependent equation of state including a first-order phase transition. These results include the time evolution of the cumulants up to third order of the...
Motivated by recent progress in spin hydrodynamics, we investigate the spin density matrix of baryons and vector mesons allowing for non-equilibrium between spin and vorticity.
We explain how the coalescence of partially polarized quarks, as well as the transfer of angular momentum from vorticity to the spin of the baryon generically create a partially coherent density matrix.
We argue that...
Higher-order cumulants of conserved quantities are proposed as key signatures for studying the QCD phase structure and for exploring the phase boundary and the critical point. It is also suggested that the correlation between baryon and strangeness number is a diagnostic to the degree of freedom of strongly interacting matter and may be used to identify the onset of deconfinement.
In this...
Baryon-strangeness (BS) correlations have been proposed as sensitive observables to probe strongly interacting matter. A particular formulation of BS correlation: $C_{BS}=-3\langle BS \rangle_c/\langle S \rangle^2_c$ (where $\langle BS \rangle_c$ is the mix-cumulant of baryon and strangeness number and $\langle S \rangle^2_c$ is the second order cumulant of strangeness) has been predicted to...
This study presents the first application of Bayesian inference to a hybrid model that combines hadronic transport as an initial state with a shear and bulk viscosity dependent on both temperature and baryochemical potential. Typically, the extraction of nuclear matter properties, such as viscosities, from experimental data involves Bayesian inference on theoretical models with parametric...
Fluid-dynamic approach should incorporate thermal fluctuations described by the fluctuation-dissipation theorem, as they may have non-negligible influence on relevant final-state observables. In this work, we introduce dynamic fluctuations into the vHLLE hydrodynamic code as a stochastic noise in linearized approximation. Such approach could help understand the evolution of fluctuations for...
Understanding the temperature dependence of the viscosity-to-entropy ratio (η/s) is essential for characterizing the properties of the matter produced in ultra-relativistic heavy ion collisions at RHIC and LHC. Low-p⊥ theory and data are, however, weakly sensitive to the commonly assumed forms of the temperature dependence of η/s, especially at high temperatures. To address this, we use...
During Run 3, the ALICE experiment has continued its exploration of the quark-gluon plasma (QGP) through the study of heavy-ion collisions at unprecedented energies of $\sqrt{s_{\mathrm{NN}}} = 5.36$ TeV in Pb–Pb collisions. This study investigates the in-medium modification of jet observables relative to the event plane as a function of certain event properties (event shape engineering), such...
Ultraperipheral collisions of relativistic heavy ion beams lead to a diverse set of photon-nucleus (photonuclear) interactions. Measurements of particles produced in photonuclear reactions can shed light on the QCD dynamics of these novel, extremely asymmetric colliding systems, with energies between those available at RHIC and the LHC. Previous studies by ATLAS have characterized photonuclear...
Energy-energy correlators (EECs), which are energy-weighted cross-sections of particle pairs, offer incisive probes into QCD dynamics, across the full scale of jet evolution, by separating energy scales in the jet fragmentation through the angular distance of the resulting particle pairs. Charged EECs probe the energy flux carried by pairs of the same or opposite electric charges. The...
LHC Run 4 will provide additional challenges in the already demanding field of charged particle track reconstruction. The Inner Detector of the ATLAS experiment will be replaced by an all-silicon inner tracker (ITk) that will consist of Pixels and Strips providing greater coverage in pseudorapidity spanning up to 8 units. The ACTS Common Tracking Software (ACTS) is the toolkit of choice that...
The pseudorapidity dependence of charged particle production provides information on the partonic structure of the colliding hadrons. It is especially interesting at LHC energies, as this observable is sensitive to non-linear QCD evolution of the initial state. For the Run~3 of LHC, ALICE has upgraded its detectors, increasing its pseudorapidity coverage and tracking of charged particles over...
In this work, we simulate $SU(3)$ color fields that
occur in the very early stages of
high-energy nuclear
collisions, using classical real-time lattice gauge theory. In particular, we model the structure of the proton and the longitudinal initial state fluctuations to simulate realistic non-boost invariant proton-nucleus collisions. We study the anisotropic momentum, and angular momentum,...
Balance functions have been used extensively to elucidate the time evolution of quark production in heavy-ion collisions. Early models predicted two stages of quark production: one for light quarks and another for the heavier strange quark, separated by a period of isentropic expansion. This led to the notion of clocking particle production and tracking radial flow effects that drive the...
Event-by-event measurements play a crucial role in understanding the high energy nuclear interaction dynamics and the properties of hot and dense medium. Fluctuations of the event-wise average transverse momentum $\langle p_T\rangle$ are related to event-by-event fluctuations of the size and entropy of the initial source. In this poster, we present the first multi-particle cumulant of $p_T$...
We explored the astrophysical properties of compact stars in the framework of renormalization Group (RG)-consistent three-flavor color superconductivity (CSC) using the Nambu-Jona-Lasinio (NJL) model with a Renormalization Group (RG)-consistent approach. We analyzed how variations in the vector interaction coupling ($\eta_V$) and diquark coupling ($\eta_D$) affect the equation of state (EoS),...
Multiplicity distributions in e+e- and proton-proton collisions analyzed via the combinants method exhibit oscillatory behavior of the modified combinants. The possible sources of these oscillations and their impact on our understanding of the multiparticle production mechanism were discussed [1-5]. The set of combinants, Cj provides a similar measure of fluctuations as the set of cumulant...
Relativistic heavy ion collisions provide exciting new ways to probe nuclear structures. In this talk, we present model-to-data comparisons for the collisions of very-deformed nuclei (U+U collisions at $\sqrt{s_{NN}} = 193$ GeV) and slightly-deformed nuclei (Au+Au collisions at $\sqrt{s_{NN}} = 200$ GeV) at RHIC. For theoretical calculations, we use a multistage model consisting of...
Exotic degrees of freedom, such as hyperons, dark matter, and deconfined quark matter, have attracted significant attention in the theoretical modeling of compact objects like neutron stars, which have extremely dense cores. Our goal is to explore the formation of these particles in high-density environments while maintaining neutron star stability and satisfying observational constraints from...
Neutron Stars (NSs) make a unique physical laboratory with extreme physical conditions that are irreproducible in experiments and capable of inducing a hadron-to-quark deconfinement phase transition in their interior. Given the high densities reached by the cold nuclear matter in NSs, it is speculated that NS cores may contain deconfined quark matter (QM). State-of-the-art inputs from...
The equation of state of nuclear matter at 2-4 times nuclear saturation density is not very well determined by first principle methods. Heavy-ion collisions offer the opportunity to reach those high densities and collective flow measurements are sensitive to the properties of the medium. At 1-2 AGeV per nucleon beam energy transport approaches are the best choice for the theoretical...
The STAR experiment conducted isobaric collisions using $^{96}_{44}\text{Ru}+^{96}_{44}\text{Ru}$ and $^{96}_{40}\text{Zr}+^{96}_{40}\text{Zr}$ ions, offering a valuable opportunity to study Coulomb dissociation and investigate nuclear structure. Although these isobars have the same mass number, their differing proton and neutron numbers may lead to distinct charge distributions and neutron...
We present a calculation of the spin alignment for unflavored vector mesons in thermalized quark-gluon plasma based on the Kubo formula in linear response theory. This is achieved by expanding the system to the first order of the coupling constant and the spatial gradient. The effect strongly relies on the vector meson’s spectral functions which are determined by the interaction and medium...
Fluctuations of conserved charges, quantified by the cumulants of order $n$ ($\kappa_{n}$) of their distributions, are powerful observables to probe the QCD phase structure, including the search for the conjectured first-order phase boundary and the associated critical point. On the experimental side, RHIC has successfully completed the second phase of its beam energy scan programme, covering...
Compressed Baryonic Matter (CBM) is a heavy-ion physics experiment designed to probe the QCD phase diagram at high densities. It is being installed at the Facility for Anti-Proton and Ion Research (FAIR) in Darmstadt, Germany, and will use a beam from the new SIS-100 accelerator. The Silicon Tracking System (STS) is the core tracking detector of CBM, tasked with achieving high-precision...
The use of neural networks in high-energy physics has rapidly expanded, particularly in jet tagging applications. This study explores two parallel methods, both leveraging convolutional neural networks (CNNs) to classify jets produced in high-energy collisions by differentiating between heavy quark (charm, bottom), light quark (up, down, strange), and gluon jets. The first method constructs...
The evolution of jets showers in high energy nuclear collisions is influenced in various ways by the presence of a surrounding medium. The interaction of jet constituents with the medium can happen during the partonic stage of the jet, during hadronization, and even during its hadronic stage. We will demonstrate how flow of the ambient medium in a direction transverse to the jet can introduce...
We discuss the thermodynamics of dense nuclear matter in the so-called parity-doublet model, in an extended mean-field approximation. Special emphasis is given to the phase structure at zero temperature and large baryon densities. The model includes the nucleon and its chiral partner. It also accommodates a nucleon mass that is compatible with the chiral symmetry of QCD, in contrast to many...
We study the minimal masses and radii of proto-neutron stars during different stages of their evolution. The main focus lies on the stages directly after the supernova outward shock wave where neutrinos are captured in the core and the lepton per baryon ratio is approximately $Y_L = 0.4$ and a few seconds afterwards, when all neutrinos have left the star. All equations of state used for this...
In high-energy physics experiments, silicon detectors play an important role in the discovery of new physical phenomena. In the research and development of detectors with silicon pad sensors, a simple preamplifier is essential to evaluate the performance of silicon pad sensors. We have therefore developed a versatile readout circuit for detectors that can be used in both test beam and...
In this poster, the first ALICE measurements of dijet invariant mass spectra of charged-particle jets are presented for pp and p--Pb collisions at $\sqrt{s_\mathrm{NN}}=5.02$ TeV. Dijet invariant mass measurements in small systems provide a baseline for dijet studies in Pb--Pb collisions, in which dijet properties can act as sensitive probes of jet quenching in the quark-gluon plasma. For this...
The dilepton production yield is sensitive to the nuclear density within the partonic and hadronic matter, which can be influenced by the initial states of the nuclei. The production of dileptons in the Au+Au and U+U collision systems is studied at relativistic heavy-ion collisions with different initial nuclear deformation profiles. Moreover, the contributions of dileptons from both...
The growing interest in the thermodynamic properties of strongly-interacting systems under rotation, particularly using lattice gauge techniques on the Euclidean manifold and with an imaginary angular velocity $\Omega = i \Omega_I$, has motivated the current study of Dirac fields under imaginary rotation. For $\nu = \beta \Omega_I / 2 \pi$ a rational number, the thermodynamics of free scalar...
The initial condition in relativistic heavy-ion collisions is sensitive to the nuclear structure of the colliding nuclei. Experimental observations in U+U and isobar collisions have revealed nuclear structure effects, such as deformation or neutron skin. For smaller colliding systems such as $^{20}$Ne+$^{20}$Ne collisions, where the number of nucleons is limited, cluster models are typically...
Ultrarelativistic isobar collisions have been proposed as a useful tool for investigating nuclear structures. The complete description of these high-energy collisions involves a hydrodynamic expansion preceded by a pre-thermal equilibrium phase. Because hydrodynamic simulations are time-consuming, isobar nuclear structure has been discussed a lot in terms of geometrical estimators such as...
The study of event-by-event transverse momentum $
In off-central heavy ion collisions (HIC), an appreciable amount of initial orbital angular momentum (OAM) of the colliding heavy nuclei can be transferred to the participants and subsequently to the nuclear medium formed [1]. This transferred OAM can give rise to local vorticity in the created matter. The transport coefficients of the matter formed in HIC give ample information about the...
In this talk, we will discuss the effects of color decoherence and virtuality evolution on jet quenching observed in relativistic heavy-ion collisions. First, we will show that the jet multiplicity, calculated according to the color coherence picture, provides a reasonable description of inclusive jet data up to $p_T \sim 1$ TeV in pp collisions at the LHC. Building on this understanding of...
Understanding energy reconstruction in the forward rapidity region is crucial for the definition of collision centrality as well as for the measurements of jet suppression in the forward region. In this poster, we discuss the performance n the forward rapidity region of the ATLAS detector in 2023 and 2024 Pb+Pb data for both total energy reconstruction and jet reconstruction. Jet...
We extensively investigate the mean transverse momentum fluctuations concerning centrality and energy dependences in Au–Au collisions at 3.0–19.6 GeV using a multiphase transport (AMPT) model. Inspired by prior research, we have adjusted the key parameter, the Lund string fragmentation parameter bL, to manifest an approximately linear dependence on the impact parameter. Consequently, the mean...
The development of the Forward Spectator Detector (FSD) of the CBM
experiment represents a crucial step towards the successful realization of the CBM
physics program – understanding of highly compressed nuclear matter at the
FAIR facility currently under construction. FSD is a scintillator-based detector which is positioned at forward rapidity in order to detect spectator nucleons and...
Jet substructure measurements, based on the distribution of final-state hadrons, offer insights into parton shower dynamics and hadronization. Observables such as the transverse momentum fraction ($j_\mathrm{T}$) and longitudinal momentum fraction ($z$) of jet constituents, provide valuable information on these processes. The ALICE collaboration has recently reported measurements of the...
For cold, ultra-dense matter, color superconductivity is characterized by the formation of Cooper pairs of quarks through gluon exchange, yielding a frequency-dependent superconducting gap on the order of 100 MeV. Conversely, the phenomenon of confinement is characterized by the fundamental particles confined within hadrons at low to intermediate energies. In this regime, lattice QCD has shown...
The spin polarization of hadrons emitted from heavy-ion collisions can serve as a probe of the angular momentum contained within the colliding system. Recent measurements of hyperon global spin polarization at midrapidity from ALICE, STAR, and HADES, spanning a collisional beam energy range from O(1000) to O(1) GeV, have shown a monotonic trend of continually increasing signal with decreasing...
In this poster, we present first results for a state of the art calculation to obtain the quark-gluon matter pressure at finite chemical potential. To this end we employ Dyson-Schwinger equations (DSE) in a 2+1 flavor scenario that has been tested successfully elsewhere in the QCD phase diagram. The equation of state for quark-gluon matter can be used as input for the hydrostatic equilibrium...
Equation of State at finite density in external magnetic fields aiming for an experimental setup
Probing the QCD phase diagram is a challenging task both from a theoretical and an experimental standpoint. Moreover heavy ion collision experiments have shown, that strong magnetic fields arise, which may have a sizeable impact on the phase diagram. From the lattice QCD perspective the...
In high-energy collisions, by measuring the two-particle Bose–Einstein correlation function and considering its relationship with the phase-space density of the particle-emitting source, we can obtain information about the source function. While a Gaussian shape is commonly assumed, anomalous diffusion suggests Lévy-stable distributions, as observed in the PHENIX experiment for kaon-kaon and...
Mean transverse momentum ($ \langle \it{p}_{\rm T} \rangle$) fluctuations are dynamic indicators of system properties, arising from correlations among the transverse momenta of final-state particles, such as those due to resonance decays and jets. Consequently, event-by-event $ \langle \it{p}_{\rm T} \rangle$ fluctuations in pp collisions serve as a model-independent baseline to explore...
In ultrarelativistic heavy-ion collisions, several nontrivial physics phenomena (e.g. collective anisotropic flow, jet quenching, etc.) can lead to persistent event-by-event azimuthal anisotropies in particle distributions, which are traditionally quantified with Fourier harmonics $v_n$. Besides the conventional measurements of individual $v_n$ harmonics, further independent information about...
Exclusive photoproduction of vector mesons offers a valuable tool for probing the gluon distribution within nucleons . Measuring vector mesons of various masses over a wide range of rapidity and as a function of transverse momentum provides important information on the evolution of the gluon distribution within nuclei. Results from $J/\psi$ and $\Upsilon$(1S) mesons in pPb collisions at a...
In this study, we investigate the effective restoration of axial U(1) symmetry by calculating the scalar and pseudo-scalar meson screening masses using Möbius domain wall fermions with physical quark masses. Unlike the widely used staggered fermions, which suffer from taste violations that lead to unphysical behavior-such as scalar screening masses failing to reach their physical values at low...
Many phenomena are expected, such as the transition to the deconfined phase and color superconductivity(CSC), in ultra-high density matter. Heavy ion collision with $\sqrt{s_{NN}}=$ <$\sim$5 GeV is expected to be most advantageous to generate and study such ultra-high densities($\rho>3\rho_{0}$).
J-PARC Heavy Ion Project(J-PARC-HI) is an experimental project aimed at studying the ultra-high...
In high-energy collider physics, a key question is whether quark--gluon plasma (QGP) is formed in proton-proton (pp) collisions. Recent observations suggest that collectivity exists in pp collisions, although signatures of jet quenching would provide stronger evidence. This study examines jet quenching in pp collisions at two different beam energies: $\sqrt{s}=13$ TeV (LHC Run 2) and...
In this presentation, we investigate femtoscopy correlation functions to access the interactions of protons across various hadrons with different baryon numbers. Beginning with the proton-pion system, we apply the results of the unitarized chiral effective theory into the TROY (T-matrix-based Routine for HAdrOn FemtoscopY) framework to predict measurable correlation functions in...
Angular (ΔηΔφ) correlations of identified particles in ultrarelativistic proton-proton and heavy-ion collisions exhibit features dependent on collision systems and particle types. These characteristics stem from mechanisms such as (mini-)jets, elliptic flow, resonance decays, and conservation laws, with quantum statistics and final-state interactions influencing each particle pair’s unique...
Understanding the phases of quantum chromodynamics (QCD) matter has become one of the important research areas for both theoretical and experimental high-energy physics community. In the QCD phase diagram, which is characterised by temperature ($T$) and baryochemical potential ($\mu_B$), a first-order phase transition is expected at high $\mu_B$ and low T, which ends at a possible critical...
An enhancement of the strange baryon-to-meson yield ratio has been observed by ALICE for intermediate transverse momentum ($p_{\rm T}$) at high multiplicity from small to large colliding systems. This enhancement is possibly due to the effects of collective radial flow and recombination of quarks. However, there is ongoing debate regarding whether jet fragmentation could also play a role, as...
The 'ALICE 3' project is a proposed upgrade of the ALICE detector, which involves a complete replacement of the installation at Point 2. Crucial to the physics programme are high-precision measurements of heavy-flavour observables that require large data samples as well as state-of-the-art tracking performance. As a consequence, performance studies of the operating conditions of ALICE 3 that...
The Compressed Baryonic Matter experiment (CBM) at FAIR is designed to
explore the QCD phase diagram at high net baryon densities and moderate
temperatures by means of heavy ion collisions with energies from 2-11 AGeV beam energy (Au+Au collisions) and interaction rates up to 10 MHz, provided by the SIS100 accelerator. Leptons as penetrating probes not taking part in the strong interaction...
We study the linear sigma model coupled with dynamical quarks undergoing rigid rotation in unbounded Minkowski spacetime under the Tolman-Ehrenfest approximation. The thermodynamics of this rigidly rotating system induces, kinematically, an infinite local temperature state at the light cylinder, where the velocity of the system equals the speed of light. We show that the infinite-temperature...
Coherent photoproduction of vector meson (VM) in heavy-ion ultrapheripheral collisions (UPCs) is highly sensitive to the gluon distributions within heavy nuclei, making it a powerful tool for probing the nuclear gluonic structure. It is of particular interest for investigating nonlinear dynamics such as gluon saturation and nuclear shadowing effects in the small Bjorken-x region. The mass of...
We present the first measurement of photoproduction of $\phi$ mesons in ultra-peripheral Au+Au collisions at a center-of-mass energy of $\sqrt{s_{NN}} = 200~\mathrm{GeV}$ using the STAR detector at RHIC. The $\phi$ mesons are reconstructed through their decay into $K^+ K^-$ pairs, enabled for the first time by the extended low transverse momentum ($p_T$) coverage provided by the STAR inner TPC...
Theory predicts that the inner structure of hadrons changes with increasing energy, and that gluon saturation can occur in heavy nuclei at lower energiescompared to protons. Additionally, phenomena such as gluon shadowing can exhibit similar experimental signatures to gluon saturation. ALICE has recently presented new results on coherent J/ψ mesons, where the photon probes the entire nucleus....
A key objective of high-energy nuclear physics is the search for the onset of gluon saturation phenomena in the limit of extreme gluon densities. Photon-induced vector meson production in ultraperipheral heavy-ion collisions (UPCs) offers a unique and powerful probe of the gluon distribution in nuclei. The $\phi$ meson, with its mass around 1 GeV, lies at the boundary of hard scales between...
We use the parametric approach to analyze jet suppression measured using the nuclear modification factor of inclusive jets and jets from gamma-jet events. With minimum model assumptions, we quantify the magnitude of the average energy loss, its pt-dependence, and flavor dependence. Further, we quantify the impact of fluctuations in the energy loss and nuclear PDFs on the measured jet...
We investigate the flavor dependence of parton splitting inside a color-deconfined medium by examining the suppression factor, substructures, and jet axis decorrelation of inclusive jets, $c$-jets and $b$-jets. Utilizing the linear Boltzmann transport model that treats light and heavy flavor parton scatterings with the quark-gluon plasma (QGP) on an equal basis, we provide a simultaneous...
In this work, we discuss the impact of phase transitions on quark spin fluctuation and correlation. We propose a novel observable for quark-antiquark correlation that relates to vector meson spin alignment and $\Lambda-\bar\Lambda$ correlation. Using the NJL model, we qualitatively study the properties of quark-antiquark spin correlation. Our findings reveal a peak structure near the CEP,...
The Forward Calorimeter (FoCal) is a new sub-detector for ALICE, planned for installation during Long Shutdown 3, designed to have unique capabilities for measuring direct photon production at forward rapidity. FoCal-H, the hadronic calorimeter segment of this upgrade, is designed as a scintillating-fiber calorimeter. Its front-end electronics utilize the H2GCROC ASIC to read out signals from...
The CERN ALICE Collaboration proposes the new ALICE 3 detection system to exploit the full potential of the HL-LHC for heavy-ion physics. The Forward Detector (FD) will be part of the ALICE 3 covering forward pseudorapidity 4 < |eta| < 7. FD will provide an interaction trigger, beam luminosity, initial vertex position, and a forward multiplicity. Its design should allow for smooth operations...
The CBM experiment at the future FAIR facility is a multipurpose forward spectrometer designed to operate at high interaction rates of up to 10 MHz, implementing a triggerless, free-streaming readout system. CBM aims to study the properties of strongly interacting matter at high baryon net density, where phenomena such as a first-order phase transition from hadronic to partonic matter and a...
Event-by-event fluctuations in the number of different particle species produced in high-energy nuclear collisions encode essential information about the phase structure of the matter created in such collisions. In this contribution, we present a novel fuzzy-logic-based approach for reconstructing arbitrary-order moments of multiplicity distributions [1]. The proposed method provides a robust...
The states of matter produced in the early stage of heavy ion collisions can be highly anisotropic. If such a feature is sufficiently pronounced, one should expect the final particle distribution inside jets to reflect it in the form of non-trivial angle correlations. In this talk, we discuss a first step in exploring such correlations by studying how a $q\bar q$ state branching from an...
Outgoing high-$p_{\rm T}$ partons produced from hard scatterings early in high-energy collisions lead to the creation of jets. Photons are produced copiously in these interactions - directly emitted by the quarks as prompt photons, or through the decay of instable particles. They are valuable probes to study jet fragmentation and nuclear parton distribution functions (nPDF).
Angular...
We will present results for the heavy quark, i.e. top-right, corner of the Columbia plot. They were derived using a 1-loop Polyakov loop potential in the center-symmetric Landau gauge, supplemented by a minimal (1 parameter), phenomenological, Curci-Ferrari extension to the Faddeev-Popov terms, which we employ to account for the effect of Gribov copies. This model has been validated in the...
The observation of collectivity and strangeness enhancement in high-multiplicity pp collisions at LHC energies has prompted discussions on the possible dynamical similarities between small systems and heavy-ion collisions. However, these phenomena alone do not conclusively indicate the formation of thermalized QCD matter. Higher-order cumulants ($\kappa_n$) of net-baryon distributions provide...
The early far-from equilibrium dynamics of the pre-hydrodynamic quark-gluon plasma (QGP) formed in heavy ion collisions can be characterized by distinct stages, during each of which the system loses some memory of its initial condition, until only the hydrodynamic modes remain. In QCD kinetic theory, this attractor behavior has been described in terms of self-similar scaling solutions for the...
Under the extreme conditions of relativistic heavy-ion-collisions hypernuclei are created with large abundancies. Hypernuclei measurements provide insights into the equation-of-state of hadronic matter at high net-baryon densities, as well as into hyperon-nucleon and hyperon-hyperon-interactions. The Compressed Baryonic Matter (CBM) experiment at the future Facility for Anti-Proton and Ion...
The observation of hyperon polarization along beam direction ($P_z$) in nucleus-nucleus collisions has opened a new way to study the complex vortical structures of the QGP. With the high-statistics data collected by the CMS experiment, we present the first $P_z$ results for $\Lambda$ and $\bar{\Lambda}$ particles in pPb collision at $\sqrt{s_{NN}}= 8.16$ TeV over a wide transverse momentum...
Inhomogenous phases or MOAT regimes of QCD matter could emerge at non-vanishing density, as demonstrated recently by calculations using functional methods. In this work, we investigate the stability of such phases within a low-energy effective theory, where the free energy F was calculated as the spatial derivative expansion of an order parameter Φ out of the Landau- Ginsburg-theory. We...
The nucleon density distribution within colliding nuclei is typically modeled using the two-parameter Woods-Saxon (WS) distribution. This conventional approach overlooks the fine radial structures arising from the quantal shell filling patterns of protons and neutrons. In this study, we incorporate these fine radial variations by utilizing density profiles from Skyrme-Hartree-Fock density...
Unravelling the hadronization mechanism in Quantum Chromodynamics (QCD) remains challenging due to its non-perturbative nature, often modelled in Monte Carlo event generators (such as PYTHIA and HERWIG) with parameters tuned to experimental data. While jets were originally proposed to circumvent non-perturbative effects and probe QCD at perturbative scales, we show that their substructure can...
We have estimated the induced electric field in quark-gluon plasma (QGP) due to its thermoelectric effects. At present, the relativistic heavy-ion collisions are capable of creating QGP, a locally thermalized medium composed of quarks and gluons.
During the space-time evolution of the QGP medium, interesting thermoelectric phenomena occur due to the presence of electrically charged particles...
The interplay of various $\pi^+ \pi^-$ photoproduction mechanisms creates a rich environment to explore the Entanglement Enabled Spin Interference (EESI) effect in different contexts. The resonance and continuum $\pi^+ \pi^-$ production originate from distinct $\gamma A$ and $\gamma \gamma$ processes offering unique opportunities to investigate production mechanisms and interference...
Relativistic heavy-ion collisions offer a unique environment for exploring quantum interference at an unprecedented femtometer scale through photon-nuclear interactions in photoproduction. In exclusive $\pi^{+}\pi^{-}$ production, the resonance and continuum $\pi^{+}\pi^{-}$ components arise from distinct production mechanisms in the $\gamma {\rm A}$ interaction. The continuum...
This study aims to investigate the antishadowing effect in nuclear parton distribution functions (nPDFs) by calculating the nuclear modification factor $R_{pA}$ for dijets produced in proton-proton (pp) and proton-lead (p-Pb) collisions. To achieve this aim, we used Monte Carlo simulations using PYTHIA and PYTHIA+POWHEG event generators. These tools allowed us to apply various nPDF sets to...
Relativistic heavy-ion collisions in the few-GeV energy range provide an opportunity to investigate the properties of nuclear matter at high net-baryon densities, similar to the conditions in Neutron Stars (NS) and Neutron Star mergers. In recent decades, significant attention has been given to the presence of hyperons in NS and their influence on the Equation of State (EoS), which describes...
Jet substructure has become a powerful tool in analyzing proton-proton collisions at the LHC. However, its implications for lower-energy jets at a collision energy of 200 GeV, as accessible at RHIC, remain largely unexplored. These lower-energy jets are more sensitive to non-perturbative effects such as hadronization and contributions from the underlying event, offering a unique opportunity to...
Jet substructure measurements in heavy-ion collisions offer vital insights into the dynamics of jet quenching within the hot and dense QCD medium generated in these events. In this talk, we present new results from the ATLAS Collaboration on jet suppression and substructure using the Soft-Drop grooming technique in Pb+Pb and $pp$ collisions at $\sqrt{s_{\mathrm{NN}}} = 5.02~\mathrm{TeV}$. The...
Jet triggering is a critical part of all jet physics measurements in LHC Run 3. In this poster, we describe the jet trigger strategy and performance in the ATLAS experiment during LHC run 3. The performance of level 1 (L1) triggers used as seeds for high-level trigger (HLT) will be shown along with typical trigger rates. While performing the underlying event (UE) subtraction at the L1 trigger...
Understanding phase transitions in relativistic heavy-ion collisions provides insights into the properties of strongly interacting matter. Key transitions include the deconfinement phase, marked by fluctuations in conserved quantities, and the chiral phase, characterized by particle ratio fluctuations that indicate chiral symmetry restoration. Kaon isospin fluctuations were studied in Pb–Pb...
Photon-photon and photon-nucleus interactions in ultraperipheral collisions of nuclei lead to the production of a wide range of particle species, which can be
observed with relatively low backgrounds. The particle species produced include heavy quark and anti-quark pairs, dileptons, vector mesons such as J/psi, and potentially exotic hadrons. The unique geometry and instrumentation of the...
PHENIX has measured the centrality dependence of two-pion Bose-Einstein correlation functions in Au+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV. The data are well represented by L\'{e}vy-stable source distributions. Three source parameters have been extracted as a function of transverse mass $m_T$ and centrality: the correlation-strength parameter $\lambda$, the L\'{e}vy index of stability...
Net-strangeness fluctuations are tightly related to the chemical composition of strongly interacting systems, and allow the study of the chiral/deconfinement transition of QCD. Thanks to their excellent signal-to-noise ratio, these observables enable a precise charting of the QCD phase diagram in the high-density region.
We present mixed baryon-strangeness fluctuations at $\mu_B=0$ up to...
In preparation for LHC Runs 5 and 6, the ALICE Collaboration has proposed a next-generation heavy-ion experiment, ALICE 3, which will be installed during the LHC Long Shutdown 4. This new experimental apparatus will feature exceptional pointing resolution and excellent Particle Identification (PID). A key component will be a Time-Of-Flight system utilizing silicon sensors, achieving an...
In ultra-relativistic heavy-ion collisions, copious rates of $\gamma\gamma$ processes are expected through the interaction of the large electromagnetic fields of the heavy nuclei. These can lead to light-by-light scattering via loop diagrams or photon-induced production of particles such as leptons or virtual axion-like particles. In ultra-peripheral collisions (UPCs), characterized by large...
We present a systematic investigation of lepton pair production through photon-photon fusion processes in heavy-ion collisions. It is demonstrated that the dilepton production at a given impact parameter ($b_\perp$) with a fixed transverse momentum imbalance ($q_\perp$) can be factorized into a unified formula in terms of the Wigner photon distribution of heavy nuclei. We show that this...
A two-dimensional intermittency analysis performed for the charged particles produced in ($\eta, \varphi$) phase space during Xe--Xe collisions at $\sqrt{s_{\rm{{NN}}}}$ = 5.44 TeV recorded with the ${\rm ALICE}$ detector at LHC is presented. A well-known characteristic of the critical behaviour of the system undergoing phase transition is that it shows fluctuations of all scales. Local...
We discuss a new numerical method for the determination the QCD critical point from first principle lattice QCD calculations. The analysis exploits the universal scaling of the Lee-Yang edge that has been obtained from lattice QCD calculations of cumulants of the baryon number density at imaginary chemical potentials. Using a multi-point Pade approximation [1] we identify the closest...
Determining the luminosity of collisions delivered by the LHC is the goal of the ATLAS luminosity programme. An accurate luminosity measurement is fundamental for any physics measurement with the ATLAS detector, in PbPb collisions especially for high precision physics measurements, such as the $\gamma\gamma\rightarrow\mu^{+}\mu^{-}$ cross section in ultra-peripheral Pb+Pb collisions. In ATLAS,...
The process of Lévy walk, i.e., movement patterns described by heavy-tailed random walks, play a role in many different phenomena, from chemical and microbiological systems through marine predators to climate change. Recent experiments have suggested that this phenomenon also appears in heavy-ion collisions. However, the theoretical background is not yet well understood. In high-energy...
The initial longitudinal structure of QGP is essential for understanding its formation, evolution, and properties in heavy-ion collisions. However, current flow decorrelation methods are limited by non-flow contamination, restricting access to the QGP's full longitudinal profile. By comparing collisions involving nuclei of similar masses but different deformations, we introduce a new approach...
This work presents the study of the strange baryon balance function in proton-proton (pp) collisions at $\sqrt{s} = 13.6$ TeV at LHC with ALICE.
Balance functions of strange baryons are sensitive to production and transport of strange quarks and their hadronization to baryons during the evolution of hot QCD matter formed in heavy-ion collisions. They are also sensitive to the diffusion of...
A jet is a spray of collimated hadrons originating from the fragmentation of an energetic parton. In heavy-ion collisions, jets traverse the colored medium and lose energy via induced gluon radiation and elastic scattering, which modify jet yields and structure. When the overlap of the colliding nuclei is small, the transverse profile of the quark-gluon plasma (QGP) is expected to become more...
Dielectron production can occur in ultra-peripheral heavy ion collisions via the Breit-Wheeler process, in which the linearly polarized photons from the heavy ion fields interact to produce low transverse momentum dielectron pairs. This production is sensitive to the electromagnetic field distributions from the heavily Lorentz-contracted nuclei, which are directly dependent on the charge...
The Silicon Tracking System (STS) in the Compressed Baryonic Matter (CBM) Experiment at FAIR’s SIS100
accelerator, aims to precisely track charged particles and determine their momenta. Its 876 double-sided micro-
strip sensors are the means to accomplish this task in the high multiplicity environment of heavy ion collisions
with high spatial, temporal and momentum resolution. A scaled down...
The STAR Collaboration reports the first measurements of the inclusive distribution of fully-reconstructed jets in peripheral (60-80%) and central (0-10%) Au + Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV at RHIC, using a dataset with an integrated luminosity of 5.2 nb$^{-1}$. The data were recorded in 2014 with an online High Tower trigger which requires at least 4.2 GeV energy...
This poster presents measurements of the di-jet momentum balance in heavy-ion collisions, focusing on anti-$k_t$ jets with varying radii ($R=$ 0.2, 0.3, 0.4, 0.5, and 0.6) using the ATLAS detector at the LHC. The analysis uses 1.72 $\mathrm{nb}^{-1}$ of Pb+Pb data collected in 2018 and 260 $\mathrm{pb}^{-1}$ of $pp$ data collected in 2017, both at a center-of-mass energy of...
In this talk we present new measurements of semi-inclusive hadron+jet correlations in pp and central Pb-–Pb collisions, using the high-statistics data sample of Run 3. Charged-particle jets recoiling from a high-$p_{\textrm{T}}$ charged hadron trigger are reconstructed with resolution parameters 0.2 and 0.4. We report the distribution of the acoplanarity observable, $\Delta \varphi$, defined...
The directed flow ($v_1$) is a sensitive probe of the initial state conditions in heavy-ion collisions. One key initial condition is the presence of a strong electromagnetic field, which induces charge splitting between particles and antiparticles and has important implications for the QCD phase transition and the properties of the Quark-Gluon Plasma (QGP) [1]. Another crucial aspect of the...
Hard probe measurements in e+e− collisions are vital for comparative studies in proton-proton and heavy-ion environments, offering a clean reference free from hadronic initial state effects. The interest in N-point energy correlation functions (ENC) has been revitalized for studying QCD, due to their distinct resolution of scales that helps in exploring QCD from perturbative to...
In this poster, we will present the first measurements of inclusive charged-particle jet spectra in various centrality classes in Pb-Pb collisions at $\sqrt{s_\mathrm{NN}} = 5.36$ TeV. In heavy-ion collisions, the measurements of jets traversing the hot medium provide critical insights into the Quark-Gluon plasma, which manifest themselves in jet energy loss and substructure modifications. The...
We report new ALICE measurements of inclusive charged-particle jet suppression and jet azimuthal anisotropy in Pb--Pb collisions. Inclusive charged-particle jet spectra in central Pb--Pb collisions at $\sqrt{s_{\mathrm NN}}$ = 5.02 TeV are measured over a broad kinematic range, including to very low jet $p_{\mathrm{T}}$, with jet resolution parameter up to 0.5, using event-mixing to correct...
Relativistic heavy-ion collisions generate extremely strong electromagnetic (EM) fields, providing an ideal environment to study the EM excitation of the vacuum. The Breit-Wheeler process, which involves the electron-position pair production via photon-photon interactions, represents the lowest-order decay mode of the QED vacuum excitation. This process was first observed by the STAR...
Due to the large mass of beauty-quarks, their production is well described by perturbative QCD (pQCD) calculations. As such, beauty jets are a powerful tool for constraining these pQCD calculations and for understanding the fragmentation of coloured massive partons. One of the main challenges in measurements of beauty jets is their accurate identification from the sample of inclusively...
This talk presents a measurement of higher order flow harmonics with order number up to 12 in lead-lead (PbPb) collisions at $\sqrt{s_{_{\mathrm{NN}}}} = 5.02$~TeV, using data collected by the CMS experiment. Higher order flow harmonics probe the initial geometry of heavy ion collisions as well as the viscous damping of flow coefficients during the evolution of the quark-gluon plasma (QGP). By...
The observables computed in simulations of heavy ion collisions are known to be highly sensitive to the initial state of the evolution. Despite advances in the modeling, fully understanding this initial state remains a challenge. In this work, we propose a method to relate final observables to the initial state, described as the sum of an average state and a random linear combination of...
The Silicon Tracking System (STS) in the upcoming heavy-ion CBM experiment is tailored for an unprecedented 10 MHz beam-target interaction rate. A unique integration strategy was employed to maintain a material budget within 2 - 8\% $X_0$ while ensuring ample granularity, spatial precision, and timing accuracy. The read-out electronics sit external to the sensitive volume, connected to...
We study the dynamics of a heavy quark propagating through strongly coupled $\mathcal{N}=4$ supersymmetric Yang-Mills (SYM) plasma. Concretely, we calculate the complete momentum broadening probability distribution due to interactions with the plasma. This calculation includes and goes beyond the classic results for the drag coefficient $\eta_D$ and momentum diffusion coefficients $\kappa_T$,...
Recently, it has been shown that investigating the structure of atomic nuclei is essential for correct description of fluctuations imprinted into the initial stage of a heavy-ion collision event. In fact, the examination of the $N$-body density distributions has shown to be crucial for better understanding deeply inelastic scattering (DIS) and nucleus-nucleus collisions [1].
Motivated by the...
The ALICE Collaboration commenced Run 3 with upgrades to the Inner Tracking System (ITS2) and the Time Projection Chamber (TPC), both pivotal for probing rare phenomena with unprecedented precision. The upgraded ITS2 enables higher tracking resolution, while the improvements to the TPC allow for continuous readout, significantly boosting resolution and data acquisition. Using these...
Energy-energy correlators and their three point counterpart have recently been of great interest to the heavy ion jet community as they directly provide the virtuality scale and are relatively simple to calculate. Recent measurements of the two point correlator in PbPb collisions compared to pp collisions by CMS show interesting trends, even when accounting for the energy loss causing a shift...
EMCal-based photon and neutral meson measurements are key parts of both the physics and calibration methods at RHIC and the future EIC. With the advent of the Electron Ion Collider, which will involve many diverse calorimeter systems, and the switch to SiPM readouts which has been occuring over the past ~decade, new techniques in calorimeter calibrations are needed. These should address for...
Neutrino transport plays a critical role in the evolution of neutron star mergers and the cooling of neutron stars. In this work, the quark core in a hybrid star is modeled with a three-flavor NJL-type model that allows for color superconductivity ([arXiv:2408.06704][1]). The rich phase structure of dense quark matter heavily influences neutrino transport. We calculate the direct Urca ...
Neutron stars offer a unique possibility to study matter under extreme conditions. The core of such an object can reach densities up to several $n_0$ which enables the possibility for a transition to quark matter. However the properties of such hybrid stars could be mimicked by dark matter and thus one needs a clear understanding of the properties for each object. To do so we study dark...
In ultraperipheral Pb+Pb collisions, intense electromagnetic fields enable the generation of magnetic monopole pairs via the Schwinger mechanism. Due to their high ionization and unique trajectories in a solenoidal magnetic field, monopoles are expected to leave a large number of clusters in the innermost ATLAS pixel detector without associated reconstructed charged-particle tracks or...
While fluctuations of the QGP initial conditions have been extensively studied in transverse plane, rapidity-dependent fluctuations remain a bit more elusive. In this talk, we present the new measures of fluctuations in the event-wise average transverse momentum, $\langle p_T \rangle$, which reflect event-by-event fluctuations of the size and entropy of the QGP initial source. We predict the...
Exclusive production processes in high-energy hadron collisions can be used to study both the gluonic structure of nucleons and the nature of exotic hadrons produced in these processes. The LHCb experiment is a unique tool for studying central exclusive production at the LHC. Recent central exclusive production measurements from LHCb will be presentend. These include studies of exclusive...
The study of particle production in heavy ion collisions provides an opportunity to investigate both the hadronic and deconfined phases of strongly interacting matter and the transition between them. By measuring changes in particle yields as a function of energy, one can explore the properties of matter at the phase transition. The NA61/SHINE experiment, a fixed-target project at the SPS...
The structure of the QCD phase diagram is a fundamental question in nuclear and particle physics. Recent works suggest the possibility of inhomogeneous phases, where key properties of quark matter such as the chiral condensate or number density adopt periodic spatial patterns. Although progress has been made in studying these phases within QCD-inspired models, direct analysis in full QCD...
The NA61/SHINE strong interaction program is based on systematic beam momentum scans (13$A$–150$A$/158$A$ GeV/$c$) involving light and intermediate-mass nuclei, ranging from proton-proton ($p$+$p$) to xenon-lanthanum (Xe+La) collisions. The program's primary scientific goals include the search for the critical point of strongly interacting matter and the investigation of phenomena related to...
In this work, we perform computations of inclusive jet, and semi-inclusive jet-hadron cross sections for minimum bias oxygen-oxygen collisions at RHIC and LHC collision energies. We compute the no-quenching baseline for the jet nuclear modification factor $R_\mathrm{AA}$ and jet-, and hadron-triggered semi-inclusive nuclear modification factors $I_\mathrm{AA}$. We do this with state-of-the-art...
Determining the type of excitations that can exist in a thermal medium is key to understanding how hadronic matter behaves at extreme temperatures. Here I report on a recent approach which utilises the non-perturbative constraints imposed by causality. By analysing finite-temperature lattice QCD data for spatial correlators of pseudo-scalar mesons comprised of light quarks, we find evidence...
The $p_T$-spectrum of the charged particles produced can be described through the fragmentation of color strings by assuming the Schwinger mechanism with heavy-tailed distributions describing the string tension fluctuations. In particular, we discuss the string tension fluctuations described by the $q$-Gaussian distribution and the one derived for the QCD-based Hagedorn function. As a result...
We present new opportunities to explore the structure of light nuclei leveraging the ability of future facilities to perform collisions with polarized deuterons and other light ions. First, we study diffractive vector meson production at small-x in the collision of electrons and polarized deuterons as anticipated at the Electron Ion Collider. We consider the polarization dependence of the...
We discuss medium effects on light cluster production in the QCD phase diagram
by relating Mott transition lines to those for chemical freeze-out.
In heavy-ion collisions at highest energies provided by the LHC, light cluster abundances should follow the statistical model because of low baryon densities. Chemical freeze-out in this domain is correlated with the QCD crossover transition....
The equation of state (EoS) at finite baryon chemical potential remains an elusive target for direct lattice QCD calculations, constituting a highly challenging topic. To address this issue, we have developed a novel Deep-learning quasi-parton model, which is constructed using three deep neural networks, to capture the fundamental properties of hot and dense QCD matter. Each neural network...
We perform a systematic study of nuclear structure parameters and their effects on (actual and potential) heavy-ion collision observables, using the Trento model of initial conditions. From a sensitivity analysis we determine which measurements and what precision are necessary for extracting particular properties such as quadrupole, octupole, and hexadecupole deformation parameters, as well...
In heavy-ion collisions, azimuthal anisotropy of the final state clearly reflects the initial geometric configuration. Recent studies have shown that the anisotropic flow $v_n$ values are enhanced by nuclear deformation parameter $\beta_n$, especially in ultra-central collisions. In mid-central collisions, the $v_n$ values are also influenced by half-height radius $R_0$ and nuclear skin...
The interactions between jets and the longitudinal-boosted quark-gluon plasma (QGP) lead to softer particles drifting away from the jet core, where high-$p_\mathrm{T}$ particles remain concentrated, resulting in an intra-jet asymmetry. Investigating this asymmetry, particularly at forward rapidities, offers a novel avenue to probe jet-medium dynamics. Using the PbPb and pp data at...
We present measurements of azimuthal acoplanarity based on direct photon ($\gamma$) and $\pi^{0}$-triggered semi-inclusive recoil jet distributions in central Au+Au and $p+p$ collisions at $\sqrt{s_{\rm NN}}=200$ GeV, using datasets with integrated luminosity of 3.9 nb$^{-1}$ and 23 pb$^{-1}$, respectively.
This observable may probe jet wake effects and Moliere scattering off of...
Unfolding, the process of correcting measured data for detector distortions, is essential for comparing collider experiments. As experimental measurements grow increasingly sophisticated, the demand for higher-dimensional unfolding methods has risen. Recently, machine learning (ML)-based unfolding approaches have emerged to address these challenges. In heavy-ion collisions, unfolding becomes...
In this talk, I will present our latest research building upon the findings of PLB 850 (2024) 138533, which demonstrated that the entropy current can be derived from first principles using the quantum statistical method, bypassing the need for assumed traditional local thermodynamic forms. Our study uncovers that the local thermodynamic relations, which have been conventionally used as...
In preparation to the LHC Run3, the LHCb gaseous fixed-target, SMOG, was upgraded to offer higher instantaneous luminosity by up to two orders of magnitude with respect to Run2, new gases, including non-noble ones such
as hydrogen, and an increased experimental accuracy. Since 2022, LHCb is working with two independent collision points and as a collider and a fixed-target
experiment...
Ultra-peripheral collisions enable a variety of two-photon and photonuclear interactions to be studied. Earlier analyses have mostly focused on exclusive photonuclear vector meson production and on two-photon interactions. This presentation will be on photonuclear interactions where the target nucleus breaks up. The cross sections for these interactions are huge in Pb–Pb collisions at the LHC....
In high-energy physics, accurately predicting cross sections of reaction processes relies heavily on the parton fragmentation functions (FFs). Conventional methods often require parameterized forms and additional calculations to ensure the FFs conform to the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi (DGLAP) evolution equations, which can be cumbersome and may not fully capture the complexity...
Much has been learned about the quark gluon plasma (QGP) produced in relativistic heavy-ion collisions, but one of the most challenging issues that still needs to be addressed is that it reaches thermal equilibrium much earlier than theoretically expected. Color glass condensation (CGC) is a strong candidate for the mechanism by which this occurs, but experimental verification has not yet been...
The Compressed Baryonic Matter (CBM) experiment is one of the experimental pillars at the Facility for Antiproton and Ion Research (FAIR).
The Silicon Tracking System (STS) is the central detector for track reconstruction and momentum measurement. It is designed to measure heavy ion collisions at interaction rates up to $10~MHz$. It comprises approximately 900 double-sided silicon strip...
A new high-precision forward calorimeter (FoCal) will be installed in the ALICE experiment at the LHC during Long Shutdown 3 for data-taking during LHC Run 4, currently scheduled for 2030-2033. FoCal consists of a Si+W sampling electromagnetic calorimeter with longitudinal and transverse segmentations (FoCal-E) and a conventional Cu+scintillating-fiber hadronic calorimeter (FoCal-H). FoCal has...
We discuss the effect of rotation on the confining and chiral properties of QCD using the linear sigma model coupled to the Polyakov loop in an attempt to resolve discrepancies between the first-principle based numerical and model-based analytical results. Working in a homogeneous approximation, we obtain the phase diagram at finite temperature, baryon density, and angular frequency. We...
Exploring the space-time extent of particle production is an important goal of heavy-ion physics and efforts have been made in order to understand the underlying physics behind the experimental observations of non-Gaussian source distributions. In experiments, femtoscopic (momentum) correlations are utilized to gain information about the space-time geometry of the particle emitting source. In...
The main goal of the RHIC Beam Energy Scan (BES) program is to explore the phase structure of strongly interacting nuclear matter and search for the possible QCD critical point (CP) in high-energy nuclear collisions. Over more than a decade, the Beam Energy Scan programs (BES-I and BES-II) at RHIC covered a wide range of collision energy, from $\sqrt{s_{\mathrm{NN}}}=$ 3.0 GeV to 200 GeV...
Hyper-order cumulants ($C_n$) of net-proton multiplicity distributions are sensitive observables for studying the QCD phase structure. At small baryonic chemical potential ($\mu_B$), lattice QCD and QCD-based models predict a negative sign for the fifth- and sixth-order cumulants as a signature of quark-hadron transition to be a crossover. At large $\mu_B$, the possibility of a first-order...
The substructure of bottom quark jets is of substantial interest, both in vacuum and in medium, in terms of understanding radiation emitted from heavy quarks. Unfortunately, the decays of b hadrons, which are typically cascading, obscure the parton level branching, by filling the radiative dead cone. To circumvent this, one may study exclusive b-hadron decays, but one then sacrifices the vast...
The CBM experiment at FAIR aims to study the properties of dense nuclear matter at the edge of the quark-gluon plasma phase transition. This extreme environment offers a unique opportunity to study hyperon-nucleon and hyperon-hyperon interactions through the production and decay of multi-strange particles and hypernuclei. Understanding these interactions is critical for describing the nuclear...
The chiral magnetic effect (CME) is a novel transport phenomenon that offers the unique opportunity for experimental observation of transitions between different vacuum topological sectors of QCD. A measurement of the CME signal also helps probe the dynamical magnetic field as well as chiral symmetry restoration, which are key ingredients of the phenomenon. Significant efforts have been made...
Investigating the presence of an electromagnetic (EM) field in the
quark-gluon plasma (QGP) has gained significant interest in heavy-ion
collision studies. The EM field is a prerequisite for observing the chiral magnetic effect (CME) and could offer insight into the conductivity of QGP. Affecting positively and negatively charged quarks differently, the fleeting EM field contributes to the...
In ultra-peripheral collisions (UPCs), coherent J/$\psi$ photoproduction has been recognized as one of the most sensitive probes of the gluon structure in nucleons and nuclei. Recently, STAR published differential measurements on photoproduced J/$\psi$ in ultra-peripheral d+Au and Au+Au collisions at $\sqrt{\mathrm{s_{NN}}}$ = 200 GeV. These results provide important constraints on gluon...
The measurement of dijets in proton-lead collisions at the LHC provides unique possibilities for investigating both nuclear and nucleon initial state effects as a function of parton scattering kinematics. In particular, color fluctuation effects can significantly alter the average interaction strength of the proton, biasing the number of nucleon-nucleon interactions with the Pb nucleus and,...
This study is the first investigation of the intricate phenomenon of shape coexistence in atomic nuclei, particularly within ultra-relativistic ion collisions. Recent findings challenge the traditional view of nuclei as fixed configurations, revealing that nuclear deformation—characterized by shape parameters $\beta$ and $\gamma$—can lead to multiple configurations. We distinguish between...
Authors: J. Aichelin, C. Blume, E. Bratkovskaya, G. Coci, S. Gläßel, V. Kireyeu, Y. Leung, V. Voronyuk, I. Vassiliev, M. Winn, Y. Zhou
The equation-of-state (EoS) at high baryon density is crucial for understanding the behavior of nuclear matter under extreme conditions. The directed flow of protons and $\Lambda$ baryons has long been proposed as a sensitive observable for probing the...
We exploit a jet substructure observable called the Lund Jet Plane (LJP) to map the momentum and angular orientation of particle emissions from a jet-initiating quark in order to study the jet evolution. This approach is useful for probing the Dead Cone phenomenon, a predicted suppression of soft gluon radiation in a conical region around the forward axis of a radiating massive quark. We...
The Transition Radiation Detector (TRD) is one of the detector
components of the CBM expriment at FAIR, currently under construction.
Multi-Wire Proportional Chambers (MWPCs) with sizes of
$99\;\textrm{cm~x~} 99\; \textrm{cm}$ and $57\;\textrm{cm~x~}
57\;\textrm{cm}$ will record particle rates up to $120\;\textrm{kHz
cm}^{-2}$: the MWPCs are therefore designed to provide fast signal...
A net baryon density up to 2-6 times the nuclear saturation density and high magnetic fields are expected in the reaction zone of upcoming CBM/NICA experiments. Such densities are also likely in the core of massive neutron stars, possibly with mixed quark-hadron phases. The chiral effective model, based on the principles of chiral symmetry breaking and broken scale invariance, is employed to...
The matrix model for the two-color QCD coupled to a single quark (matrix-QCD$_{2,1}$) exhibits novel features, such as the Pauli-Gursey symmetry. Using variational methods, we numerically investigate matrix-QCD$_{2,1}$ in the limit of ultra-strong Yang-Mills coupling ($g_{YM} =\infty$). The spectrum of the model has superselection sectors labelled by baryon number $B$ and spin $J$. We study...
We present a detailed numerical and analytical study of the out-of-equilibrium dynamics of Model G, the dynamical universality class relevant to the chiral phase transition. We quench the system from the high temperature, unbroken phase to the broken phase and study the real-time dynamics of the Goldstone modes, i.e. pions. Strikingly, the non-equilibrium evolution of the two-point functions...
Fluctuations of conserved quantities are proposed as a useful observable to study the QCD phase structure including the search for the first-order phase boundary and critical point. Lattice QCD calculations have shown that there is no critical point for $\mu_B \le$ 450 MeV and few phenomenology models calculations have shown that the critical point could be at temperature of $T \sim$ 100 MeV...
Fluctuations of conserved quantities are proposed as a useful observable to study the QCD phase structure including the search for the first-order phase boundary and critical point [1]. Lattice QCD calculations have shown that there is no critical point for baryon chemical potential $\mu_B \le $ 450 MeV and a few phenomenology models calculations have shown that the critical point could be at...
To bridge the gap between the theory of the QCD phase diagram and the phenomenology of heavy-ion collisions it is important to understand the real-time dynamics of hot and dense QCD matter. One commonly employed low-energy effective theory for the QCD phase structure is the quark-meson model. In this talk, I will show how the real-time dynamics of the quark-meson model can be studied...
We investigate the dissipation rate of a scalar field in the vicinity of the phase transition and the ordered phase, specifically within the universality class of model A. This dissipation rate holds significant physical relevance, particularly in the context of interpreting effective potentials as inputs for dynamical transport simulations, such as hydrodynamics. To comprehensively understand...
The Nambu-Jona-Lasinio (NJL) model and specifically its extension to color superconductivity (CSC) is an effective model for investigating dense quark matter. However, the reliability of its results is challenged by cut-off artifacts emerging near cut-off energy scales. In this presentation, I focus on a Renormalization Group (RG) treatment that successfully eliminates these artifacts(arXiv...
The fourth-order cumulant of quadrangular flow ($\bf{v}_4$), $C_4\{4\}$, exhibits a distinct trend in Pb-Pb collisions at the LHC energy [1]: negative for 0-20% centrality, changes sign and becomes positive around 20-30% centrality, and remains positive throughout the remaining centrality range. This measurement, made over half a decade ago, remains unexplained. We attribute the observed sign...
Recent experimental results on two-particle correlations within jets with extremely high multiplicities in pp collisions highlight a strong flow-like correlation among constituents. One of the hypotheses to describe this effect suggests the formation of a hot and dense QCD medium within the jet cone, a phenomenon previously thought to occur exclusively in heavy-ion collisions. One notable...
I discuss the neutron star equation of state. I demonstrate that the restoration of conformal symmetry requires changing the sign of the curvature of the energy per particle. I argue that the curvature of the energy per particle may serve as an approximate order parameter that signifies the onset of strongly coupled conformal matter in the neutron star core. Lastly, I relate the thermodynamic...
A key physical target of relativistic heavy-ion collision experiments is to understand the phase structure of Quantum Chromodynamics (QCD) and search for the critical endpoint (CEP). The primary experimental approach to locating the CEP is measuring the baryon number fluctuations. In the energy region currently being studied, the baryon number is primarily carried by protons and neutrons. Due...
Heavy-ion experiments provide a new opportunity to gain a deeper understanding of the structure of nuclei. To achieve this, it is crucial to identify observables under circumstances that are minimally affected by the process that leads to the initial state of heavy-ion collisions from nuclear wave function. In this talk, we demonstrate that when assuming scale invariance, the effect of this...
Understanding the many-body properties of ground-state light nuclear shape, is a key question to further study initial conditions and collectivity in high-energy small system collisions at RHIC and the LHC. In this talk, we interface insights from ab initio nuclear structure calculations of $^{16}$O geometry with simulations of high-energy $^{16}$O+$^{16}$O collisions. Bulk observables, such...
The coherently produced vector meson in ultraperipheral collisions (UPCs) at high energies serves as a powerful tool for probing the nuclear gluon density. We are studying the production cross section of $\rho^{0}$ mesons in PbPb UPCs at $\sqrt{s_{NN}}$ = 5.36 TeV, having an integrated luminosity of 1.68 $\mu b^{−1}$, with the CMS detector. The contributions from the continuum and the resonant...
We investigate saturation effects in exclusive vector meson production in deep inelastic scattering (DIS), where we model fluctuations within the target protons as localized color charge hotspots. Using the Color Glass Condensate (CGC) framework and the dipole picture for vector meson production, we examine the coherent and incoherent scattering cross sections' dependencies on momentum...
The existence and location of the QCD critical point are objects of both experimental and theoretical studies. The comprehensive data collected by NA61/SHINE during a two-dimensional scan in beam momentum and system size allow for a systematic search for the critical point - a search for a non-monotonic dependence of various correlation and fluctuation observables on collision energy and size...
Significant efforts have been made within the heavy-ion collision community to locate the QCD critical endpoint (CEP). Recent lattice QCD studies using imaginary chemical potentials, based on simulations at temperatures above 120 MeV and utilizing Lee-Yang edge singularities in the complex chemical potential plane, suggest that the critical temperature at the CEP, $ T_c^{CEP}$, should be...
Searching dark portal particle is a hot topic in particle physics frontier. We present a simulation study of an experiment targeted for searching the scalar portal particles and vector portal particles at Huizhou $\eta$ factory. The HIAF high-intensity proton beam and a high event-rate spectrometer are suggested for the experiment aimed for the discovery of new physics. Under the conservative...
The ALICE Experiment will upgrade the innermost three layers of its Inner Tracking System (ITS) during the next LHC Long Shutdown (LS3). It is planned to partially replace the existing conventional setup using individual chips on staves by a novel concept, where wafer-scale sensors are bent to half-cylinders allowing for a tracker with an extraordinarily low material budget of $0.07\%~X/X_0$...
Two-particle correlation functions of hadrons are sensitive to mechanisms of particle production and transport in elementary particle collisions. The production of quarks is determined by coupling terms of the QCD Lagrangian. These nominally conserves quark flavors in addition to energy, momentum, and electric charge: flavor currents are conserved at the level of quarks and gluons. The...
SiPM (Silicon PhotoMultiplier) sensors are one of the technologies under study for the outer timing layer of ALICE 3, a next-generation multipurpose detector at the LHC which will replace the present ALICE experiment for Run 5 and beyond.
SiPMs are usually coupled to scintillators or Cherenkov radiators. Nonetheless, in recent studies it has been shown that SiPMs can directly detect charged...
Theoretical modelling of the neutron and proton ZDC signals in heavy ion collisions is in its infancy due to its unique dynamics of spectator nucleons. Spectators, often forming clusters with varying charge-to-mass ratio, may fail to reach either ZDC and also single proton spectators are challenging to model due to the beamline magnetic fields. Despite these challenges, spectator production...
In this talk I will discuss the properties of the 2SC-phase of dense quark matter. We formulate the quark-meson diquark model as an effective low energy model of QCD. We then calculate the thermodynamic potential to one loop including quark loops. The phase diagram in the $\mu_B-T$ plane is mapped out. We focus on the speed of sound $c_s$ at $T=0$. $c_s$ has a distinct peak of $c_s\approx0.4$...
sPHENIX, located at the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, is a multipurpose proton and ion collider detector, and a central piece of its physics program is the measurement of open heavy flavor production in both pp and AuAu collision systems. Production of D mesons, both prompt and as cascade decays from B mesons, provide clean probes of the Quark Gluon Plasma....
The sPHENIX experiment is a next-generation collider detector at RHIC designed for rare jet and heavy flavor probes of the Quark-Gluon Plasma and polarized proton-proton collisions. sPHENIX includes large-acceptance electromagnetic and hadronic calorimetry, the latter of which for the first time at RHIC, as well as a four-subsystem precision tracking system comprising a MAPS-based silicon...
The sPHENIX experiment operating at RHIC aims to make high precision measurements of jets and heavy flavor observables for a wide selection of nuclear collision systems. Its tracking system is composed primarily of 4 subsystems that work in tandem to reconstruct the path of ionizing radiation through the detector geometry. Starting with the innermost detector and moving radially outward, the...
The sPHENIX experiment is a state-of-the-art detector at the Relativistic Heavy Ion Collider
(RHIC) which represents the first detector with both electromagnetic and hadronic
calorimeters with full azimuthal coverage and wide rapidity acceptance centered at
midrapidity, thus making it well suited to measure jets. This poster presents a study of
calorimeter energy-energy correlator at 0.1 <...
There is considerable evidence suggesting the existence of QGP droplets even in small collision systems, such as p+p and p+A collisions. Measurements of long-range correlations are important to evaluate the interplay between the role of initial and final state effects. The sPHENIX experiment at RHIC began operations in 2023 and took p+p collision data over a period of five months in 2024. In...
The sPHENIX experiment is a next-generation collider detector at RHIC designed for rare jet and heavy flavor probes of polarized p+p collisions. The experiment includes a large-acceptance, granular electromagnetic calorimeter (EMCal) and very high-rate data acquisition plus trigger system. In RHIC Run-24, sPHENIX sampled 107/pb of transversely polarized p+p collision data at 200 GeV using an...
The sPHENIX experiment is a next-generation collider detector at RHIC designed for rare jet and heavy flavor probes of the Quark-Gluon Plasma. The experiment includes large-acceptance, electromagnetic (EMCal) and hadronic (HCal) calorimeter systems, along with a very high-rate data acquisition plus trigger system. In RHIC Run-24, sPHENIX sampled 107/pb of p+p collision data at 200 GeV using an...
Machine learning models have previously been utilized to address the challenge of subtracting combinatorial backgrounds from jets in heavy-ion collisions, with most earlier efforts focusing on supervised regression models. In this talk, we introduce the first self-supervised application of a generative AI model for jet background subtraction. We utilize UVCGAN [1], a Cycle Consistent...
sPHENIX is a second generation RHIC experiment, designed for precise measurements of QGP properties and the nature of the proton spin structure. The Intermediate Si Tracker (INTT) is a two-layer cylindrical tracker using Si strip sensors, with strip size is 78 um x 1.6 cm. The INTT plays a key role for the charged particle tracking and the determination of a collision time. For these purposes,...
The sPHENIX detector at the Relativistic Heavy Ion Collider (RHIC) is designed to study the small scale structure of the quark-gluon plasma (QGP) created in heavy ion collisions. Jets, produced in hard scatterings early in the collisions, provide an ideal probe for the full evolution of the QGP. Jets produced back-to-back with photons are an ideal probe of the QGP as the photons do not...
The sPHENIX experiment is a next-generation collider detector at RHIC designed for rare jet and heavy flavor probes of the Quark-Gluon Plasma. The experiment includes a suite of precision tracking detectors for measurements of jet structure, open heavy flavor, and quarkonia. The tracking system includes a MAPS-based silicon pixel detector, a fast silicon strip detector, a compact time...
Luminosity determination in ALICE is based on the van der Meer (vdM) scan procedure. The vdM scan data in Run 3 are collected through subsystems such as Fast Interaction Trigger (FIT), Zero Degree Calorimeter (ZDC), and Inner Tracking System 2 (ITS2). In the vdM scan, the two beam bunches are moved in opposite directions along the horizontal or vertical axis. The visible cross section is...
The Compressed Baryonic Matter experiment (CBM) is a main scientific pillar of FAIR, the Facility for Antiproton and Ion Research, currently being constructed in Darmstadt, Germany. CBM will study the phase diagram of baryonic matter in regions of moderate temperature and large baryonic chemical potential, reaching net baryon densities several times larger than ordinary nuclear matter. Some...
We utilize 3+1-d stochastic hydrodynamics to study correlations and fluctuations of baryon charge in high-energy heavy-ion collisions. The baryon charge fluctuations are important observables to probe the QCD phase diagram, while a dynamical description through stochastic hydrodynamics remains challenging due to numerical instabilities and high computation demands. In this work, we employ a...
The improved read-out system implemented in ALICE in Run 3 opens the possibility to study photonuclear production of strange particles in a new and unique energy range. The study of strange hadrons across various collision systems and sizes has received renewed interest, particularly in understanding hadronization models. Systematic studies of baryons with varying strangeness content has...
Shock waves in matter produced under extreme conditions drive complex processes like energy transfer, particle acceleration, and plasma instability. Magnetic fields alter the shock wave properties of matter produced in heavy ion collisions and astrophysics, influencing energy density, pressure, and turbulence in these extreme conditions. How magnetic fields impact shock wave evolution in both...
The measurements of Lambda transverse polarization, i.e. the polarization in the direction transverse to the lambda production plane, have a long history. The unexpected observation of significant Lambda hyperon polarization in inclusive p+p and p+A collisions using unpolarized beams triggered theoretical efforts to describe this effect. Numerous models have been proposed to explain the origin...
Entanglement Enabled Spin Interference (EESI), an example of the Cotler-Wilczek process, was used to measure the structure of nuclei and neutron skins in ultraperipheral (UPC) Au+Au and U+U collisions. Study of the interference in peripheral collisions provides novel information on the impact parameter dependence, the entanglement criteria, and wavefunction decoherence. On one hand, the medium...
We present a comprehensive differential study of $\Lambda$ hyperon polarization in Au+Au collisions at low and intermediate energies and different impact parameters, employing the microscopic transport model UrQMD in conjunction with the statistical hadron-resonance gas model. We show that in central collisions the resulting thermal vorticity configuration effectively manifests as the...
The Compressed Baryonic Matter (CBM) experiment at Facility for Antiproton and Ion Research (FAIR), Darmstadt, offers a unique opportunity to study the model-predicted first-order transition from hadronic phase to Quark Gluon Plasma (QGP) phase with high precision by using its exceptionally high collision rates of up to 10 MHz, far surpassing previous experiments.
Event-by-event fluctuations...
The angular correlation function is a key tool in the study of hadronization mechanisms. Several effects influence these functions, including quantum statistics, final state interactions, energy and momentum conservation, resonance decays and the quark composition of the interacting particles. This serves as a powerful tool for checking the validity of the theoretical models.
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This...
To quantify the properties of hadronic collisions at LHC energies, a precise understanding of the system's spatial and temporal evolution is essential. Femtoscopic correlations provide a powerful tool for measuring the size of the homogeneity region at kinetic freeze-out. In this analysis, we measure femtoscopic correlations within jets produced in proton-proton collisions at $\sqrt{s} = 13$...
In relativistic heavy-ion collisions at the LHC, the quark-gluon plasma (QGP) is produced. The transition is achieved when the system reaches a specific critical temperature ($T_{\mathrm{ch}}$). Lattice QCD calculations indicate that chiral symmetry (CS) restoration occurs around $T_{\mathrm{ch}}$ as well ($\sim 156$ MeV). CS restoration can be investigated using resonances that are parity...
Heavy-ion collisions at the LHC provide a fascinating testing ground for studying fundamental physical effects in Quantum Chromodynamics (QCD), such as the production of conserved charges at a microscopic level. The goal of this analysis is to study the production mechanisms for strangeness and baryon number, as well as how these mechanisms affect each other, in a QCD-dominated environment....
Space–time properties of particle-emitting sources created in heavy-ion collisions can be studied with femtoscopic techniques using momentum correlations based on quantum statistics, Coulomb and strong interactions. In this talk, the most recent results of femtoscopic analysis of identical proton pairs in Pb--Pb collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.36 TeV based on data collected by ALICE...
We introduce the ``target jet" in the forward region of the ion in deep inelastic scattering (DIS) events with a jet radius which depends on the DIS kinematics in order to separate the current and target regions in the laboratory frame. We show that target jet substructure and its correlation with the substructure of the leading jet is sensitive to the internal structure of nucleon and ion,...
In this work, we investigate the phase diagram of the (2+1)-dimensional Gross-Neveu-Yukawa (GNY) model under strong magnetic fields at finite temperature and density. Large magnetic fields result in magnetic catalysis, a dimensional reduction of the system and enhancement of the chiral symmetry breaking. Using the functional renormalization group (FRG) in a hydrodynamic approach allows us to...
The ALICE Forward Calorimeter (FoCal) detector upgrade is designed to probe hadronic matter, its gluon density and the parton distribution functions at Bjørken-$x$ in the order of and smaller than 10⁻⁶. Located 7$\,\mathrm{m}$ away from the LHC interaction point, it will cover a pseudo-rapidity range of 3.2 < η < 5.8. The calorimeter will be composed of a 20-layer Si-W sampling electromagnetic...
Track reconstruction in high-multiplicity events, such as heavy-ion collisions at LHC, is a difficult and resource-demanding process. A priori knowledge of the collision vertex position would allow discarding non-viable track seeds, reducing the overall computing requirements for the track reconstruction. Traditionally, the vertex position is estimated only after the track reconstruction,...
In this talk, I will introduce recent progress in applying machine learning to the holographic QCD phase, the heavy quark potential and mass spectrum. We utilize machine learning to input the equation of state and baryon number susceptibility into the holographic model. Then, using this machine learning-enhanced holographic model, we predict the heavy-quark potential and transport properties...
Kaluza and Klein proposed a theory with a compactified extra dimension, which may appear in high-energy reactions or in the presence of superdense matter. In this work, I show how astrophysical observables will be modified in the presence of extra compactified dimensions.
The interior of a compact star is modeled as a multidimensional interacting degenerate Fermi gas, embedded in a static,...
We calculate several observables probing jet phenomena in heavy-ion collisions that propagates JEWEL medium-modified parton showers in event-by-event (2+1)D v-USPhydro profiles with $\rm T_RENTo$ initial conditions. The jet-hydro interface incorporates finer features from the hydrodynamic calculation, such as local fluid velocity and the applied equation of state, to realistically simulate...
The Micro Vertex Detector (MVD) is the first downstream detector of the fixed-target CBM experiment at the future Facility for Antiproton and Ion Research (FAIR). It enables high-precision tracking of low-momentum particles in direct proximity of the target, e.g., the first out of four planar stations is placed only 8 cm downstream the interaction point. Thus, minimizing the material budget...
The Compressed Baryonic Matter (CBM) experiment will be installed at the Facility for Antiproton and Ion Research (FAIR). It aims to explore the phase structure of strongly interacting (QCD) matter at large net-baryon densities and moderate temperatures by means of heavy-ion collisions in the energy range $\sqrt{s_{NN}} = 2.9 - 4.9$ GeV. A key observable for the anticipated first order phase...
Dense QCD matter may exhibit crystalline phases. Their existence is reflected in a moat regime, where mesonic correlations feature spatial modulations. We study the realtime properties of pions at finite temperature and density in QCD in order to elucidate the nature of this regime. We show that the moat regime arises from particle-hole-like excitations near the Fermi surface. This gives rise...
Jets are collimated bunches of hadrons, and they serve as a useful tool for studying QCD. Jets are generated from the hard scattering processes of quarks and gluons in particle collisions, such as those at the Large Hadron Collider (LHC). These processes can be theoretically described by perturbative QCD (pQCD) and are well-modeled by Monte Carlo simulations such as PYTHIA and...
An investigation of QCD with larger than physical quark masses offers a valuable insight into the physics of deconfinement.
In an effective Polyakov loop model, we show the interplay between the imaginary and real Polyakov loop susceptibility ratio and the baryon number kurtosis. As the quark mass increases, both quantities approach a step-function behaviour. This suggests that the...
Relativistic heavy-ion collisions offer a unique opportunity to probe the deformation of colliding nuclei. The quadrupole deformation parameter ($\beta_2$) has been extensively studied through the flow coefficient $v_2$ in such collisions, as well as through low-energy measurements of the electric quadrupole transition probabilities, B(E2). In contrast, the hexadecapole deformation ($\beta_4$)...
The nature of the QCD phase transition in the chiral limit presents a challenging problem for lattice QCD. However, its study provides constraints on the phase diagram at the physical point. In this work, we investigate how the order of the chiral phase transition depends on the number of massless quark flavors. To approach the lattice chiral limit, we map out the chiral critical surface that...
The J-PARC E16 experiment has the goal to search for signatures of the spontaneously broken chiral symmetry and its (partial) restoration, through the study in-medium modification of the vector mesons, particularly the phi meson, decaying via di-electron channel, with a high intensity 30 GeV proton beam interacting with C and Cu targets at rates up to 10 MHz. For this purpose, the experiment...
The dual-radiator RICH (dRICH) detector of the ePIC experiment at the future Electron-Ion Collider (EIC) will make use of silicon photomultiplier (SiPM) sensors for the detection of the Cherenkov light emitted by particles crossing its radiators. The photodetector will cover $\sim$ 3 m$^{2}$ with 3$\times$3 mm$^{2}$ pixels, for a total of more than 300k readout channels. This will be the first...
We study the finite temperature equation of state by using an effective lagrangian in which a dilaton field reproduces the breaking of scale symmetry in QCD.
We start by extending a previous investigation in the pure gauge sector $SU(3)_c$ [1], where the dynamics of the gluon condensate, expressed in terms of a dilaton lagrangian, is dominated below the critical phase transition temperature...
We analyze the role played by thermal resonances in chiral and $U(1)_A$ transitions. The analysis will be carried out by studying several theoretical approaches based on effective theories. In particular, we will be interested in observables related to chiral symmetry restoration for which the lightest degrees of freedom provide the dominant effect. We will also discuss recent work on...
In this talk, we will present our extended studies on the bottom-up thermalization for a system composed by quarks, antiquarks and gluons. We will begin by performing parametric estimates for three distinct stages prior to hydrodynamization in the weak-coupling/high-energy limit, completing the analysis for pure gluon systems conducted by Baier, Mueller, Schiff, and Son. The predicted scaling...
We explore the thermodynamic geometry in the context of the chiral phase transition of Quantum Chromodynamics. In particular the thermodynamic curvature, $R$, provides insights into the system's fluctuations and critical behavior and thus can be considered as an alternative way to approach the study of critical phenomena. Building upon previous studies, we incorporate bosonic fluctuations...
The characteristics of the system created in collisions of heavy ions can be explored via spatial and temporal parameters obtained using the method of correlation femtoscopy.
At low energies, the size of the particle emission region extracted from femtoscopic correlations is affected by the initial system isotopic spin and Coulomb interaction of the correlated particles with the residual...
The spatiotemporal properties of the system created in heavy-ion collisions, including key information about its size and dynamics, can be studied via femtoscopy. In this talk, a differential study of the system size of Pb–Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.36 TeV with ALICE Run 3 data using correlations in momentum space of charged pion–pion pairs is presented.
In this study, the...
The study of the two-particle number correlation function, $R_{\rm 2}$, and the transverse momentum correlation function, $P_{\rm 2}$, has proven to be a crucial toolset to characterise the medium created during heavy-ion collisions. To complement the recent ALICE measurement in minimum-bias pp collisions, this contribution presents the study of multiplicity and transverse spherocity...
Higher-order moments of conserved charge fluctuations, such as net-charge, net-baryon, and net-strangeness, are sensitive experimental probes for investigating the critical fluctuations in relativistic heavy-ion collisions. We calculate the cumulants and correlation functions of proton, antiproton, and net-proton multiplicity distributions in Au + Au collisions at √sNN = 7.7 GeV using a...
An understanding of the energy loss of fast partons passing through the strongly interacting quark-gluon plasma (QGP) is important for the interpretation of experimental data on jet attenuation in the QGP created in heavy-ion collisions, as well as for the study of the modification of the QGP itself. However, gaining this knowledge is a challenging task, since it is related to the...
The most recent measurements of femtoscopic correlations at NA61/SHINE, using intermediate collision systems, unravel that the shape of the particle emitting source exhibits non-Gaussian properties over the available energies. The measurements are based on alpha-stable symmetric Lévy sources, and we discuss the average pair transverse mass dependence of the source parameters. One of the...
The collision of a proton and a lead nucleus is asymmetric in nature, leading to an asymmetric rapidity distribution (more particles produced in the Pb-going side) of the produced particles at ultrarelativistic energies. We study multiplicity in such collision as a function of pseudorapidity, and centrality defined from the energy deposited in a calorimeter. In particular, we focus on the...
We report our new results on the chiral crossover transition in 2+1 flavor QCD on $N_\tau=8$ lattice using the Mobius domain wall fermion (MDWF) discretization scheme. By performing a high statistics study of the disconnected part of the chiral susceptibility, $\chi_{disc}$, we extract a pseudo-critical temperature, $T_{pc}=158.9(-2.1)(+2.6)$ MeV. This is in very good agreement with the...
We study the critical dynamics of a scalar field theory with $Z_2$ symmetry in the dynamic universality class of Model A in two and three spatial dimensions with classical-statistical lattice simulations. In particular, we measure the non-equilibrium behavior of the system under a quench protocol in which the symmetry-breaking external field is changed
at a constant rate through the critical...
Understanding the impact of nuclear structure in high-energy nuclear collisions is critical to advancing our knowledge of quark-gluon plasma (QGP) formation. In this study, we investigate the role of nuclear clustering, in particular the alpha-cluster structure in $\rm ^{16}O$, using anisotropic flow observations from $\rm ^{16}O+^{16}O$ collisions at RHIC energy. Through systematic...
Jet substructure measurements at the LHC produce precision tests of jet formation and fragmentation in vacuum as well as at the high temperatures and densities formed in heavy-ion collisions. Jets containing a heavy-flavor hadron drive these QCD measurements into a regime where parton mass and colour factors are critical, pushing the limits of theoretical calculations both in-vacuum and...
Recent CMS measurements of high-multiplicity jets have revealed intriguing structures in two-particle correlations within jets containing over 80 charged tracks, potentially indicating the presence of final-state interactions beyond those modeled in existing parton shower frameworks. We investigate two mechanisms of final-state interaction that may become significant when the phase-space...
Recent heavy-ion collision experiments at intermediate energies are intensively focused on probing the QCD phase diagram to reveal critical behavior associated with the possible critical point. In these collisions, the produced fireball exhibits significant inhomogeneity along the rapidity direction, covering a broad region of the QCD phase diagram. This spatial variation offers a unique...
We explicitly verify the validity of the open source package KøMPøST~[1] for modelling the early time dynamics of the QGP in heavy ion collisions. Since KøMPøST is based on the dynamics of a kinetic theory description to implement a macroscopic evolution of the energy-momentum tensor, we assess its applicability by comparing KøMPøST results to fully microscopic calculations in kinetic theory...
We begin by using Hybrid Model calculations to reproduce experimental results published by ATLAS in 2023 on $R_{AA}$ for $R=1$ jets in Pb+Pb collisions. These jets are identified by first reconstructing anti-$k_t$ $R=0.2$ subjets and then re-clustering them. Following ATLAS, we investigate how $R_{AA}$ for these large-radius jets depends on the angle between the two subjets involved in the...
The Wiedemann-Franz law, a hallmark of non-relativistic electron transport, relates the thermal and electrical conductivities through a constant Lorenz ratio. This ratio remains fixed in conventional metals, consistent with Fermi gas and Fermi liquid theory. Interestingly, quarks or hadrons in the matter produced in RHIC or LHC experiments don't follow this law. This high-energy nuclear...
