Using event-by-event fluctuations, we study the diffusion parameters of net-charge, net-pion, net-kaon, and net-proton in the heavy-ion jet interaction generator (HIJING), and ultra-relativistic quantum molecular dynamics (UrQMD) models at different collision energies \sqsn available at BNL Relativistic Heavy Ion Collider (RHIC). The diffusion parameter ($σ$) of net-charge and identified particles are estimated in rapidity space at various \sqsn. It is observed that, the $σ$ values are independent of collision energies but emphasises the particle-species dependence of diffusion coefficient in the QGP medium. The present work on particle-species dependence of diffusion coefficient provides a baseline for comparison with the experimental data.
We use an event-by-event hydrodynamical description of the heavy-ion collision process with Glauber initial conditions to calculate the thermal emission of photons. The photon rates in the hadronic phase follow from a spectral function approach and a density expansion, while in the partonic phase they follow from the AMY perturbative rates. The calculated photon elliptic flows are lower than those reported recently by both the ALICE and PHENIX collaborations.
It was proposed that the electric fields may lead to chiral separation in QGP, which is called the chiral electric separation effect. The strong electromagnetic field and the QCD vacuum can both completely be produced in the off-central nuclear-nuclear collision. We used the Wood-Saxon nucleon distribution to calculate the electric field distributions of the off-central collisions. The chiral electro field spatial distribution at Relativistic Heavy-Ion Collider (RHIC) and Large Hadron Collider (LHC) energy regions are systematically studied in this paper. Compared with magnetic field spatial d…
Widths of the rapidity distributions of various identified hadrons generated with the UrQMD-3.4 event generator at all the Super Proton Synchrotron (SPS) energies have been presented and compared with the existing experimental results. An increase in the width of the rapidity distribution of $Λ$ could be seen with both Monte Carlo (MC) and experimental data for the studied energies. Using MC data, the study has been extended to Relativistic Heavy Ion Collider (RHIC) and Large Hadron Collider (LHC) energies. A similar jump, as observed in the plot of rapidity width versus rest mass at Alternati…
We study the fluctuations of net-charge, net-pion, net-kaon and net-proton using $D$-measure and $ν_{dyn}$ variables in heavy-ion jet interaction generator (HIJING), ultra-relativistic quantum molecular dynamics (UrQMD), and hadron resonance gas (HRG) model at different collision energies \sqsn. It has been observed that, the values of $D$ strongly dependent on $Δη$ in HIJING and UrQMD models and independent in HRG model. The diffusion coefficients ($σ$) of identified particles are estimated at various \sqsn. It is observed that, the $σ$ values are independent of collision energies but emphasi…
We investigate the form of the viscous correction to the equilibrium distribution function in the context of a Cooper-Frye freeze out prescription for viscous hydrodynamic simulations of relativistic heavy ion collisions. The standard quadratic ansatz used by all groups for the case of shear viscosity is found to be disfavored by experimental data for v4/(v2)^2 at the Relativistic Heavy Ion Collider, and is unlikely to be correct for the hadron resonance gas present at freeze out. Instead, data for v2(pt) along with v4/(v2)^2 favor a momentum dependence between linear and quadratic.
We compute v4/(v2)^2 in ideal and viscous hydrodynamics. We investigate its sensitivity to details of the hydrodynamic model and compare the results to experimental data from RHIC. Whereas v2 has a significant sensitivity only to initial eccentricity and viscosity while being insensitive to freeze out temperature, we find that v4/(v2)^2 is quite insensitive to initial eccentricity. On the other hand, it can still be sensitive to shear viscosity in addition to freeze out temperature, although viscous effects do not universally increase v4/(v2)^2 as originally predicted. Consistent with data, we…
We analyze the transverse momentum distribution of $J/ψ$ mesons produced in Au + Au collisions at the top RHIC energy within a blast-wave model that accounts for a possible inhomogeneity of the charmonium distribution and/or flow fluctuations. The results imply that the transverse momentum spectra of$J/ψ$, $ϕ$ and $Ω$ hadrons measured at the RHIC can be described well if kinetic freeze-out takes place just after chemical freeze-out for these particles.
We investigate the energy losses of $b$ and $c$ quarks at hard collisions with gluons and light quarks in quark-gluon plasma produced in central $Au + Au$ collisions at RHIC energy($\sqrt{s_{NN}} = 200$ GeV). As the coupling constant at hard collision in the perturbative QCD is limited by Landau pole at momenta $Q^{2} = Λ^{2}$, we use the analytic models of QCD, where the Landau pole is absent. We calculate the energy losses of $b$ and $c$ quarks in analytic model of QCD at $Q^{2} \ge Λ^{2}$. At calculations we use the effective quasiparticle model. We use at calculations of total nuclear modi…
Based on the recent RHIC and LHC experimental results, the $\langle p_T\rangle$ dependence of identified light flavour charged hadrons on $\sqrt{(\frac{dN}{dy})/S_{\perp}}$, relevant scale in gluon saturation picture, is studied from $\sqrt{s_{NN}}$=7.7 GeV up to 5.02 TeV. This study is extended to the slopes of the $\langle p_T\rangle$ dependence on the particle mass and the $\langleβ_T\rangle$ parameter from Boltzmann-Gibbs Blast Wave (BGBW) fits of the $p_T$ spectra. A systematic decrease of the slope of the $\langle p_T\rangle$ dependence on $\sqrt{(\frac{dN}{dy})/S_{\perp}}$ from BES to t…
We propose the development and construction of a novel muon-ion collider (MuIC) at Brookhaven National Laboratory (BNL) in the USA as an upgrade to succeed the electron-ion collider (EIC) that is scheduled to commence in the early 2030s, by a joint effort of the nuclear and particle physics communities. The BNL facility could accommodate a muon storage beam with an energy up to about 1~TeV with existing magnet technology. When collided with a 275~GeV hadron beam, the MuIC center-of-mass energy of about 1~TeV will extend the kinematic coverage of deep inelastic scattering physics at the EIC (wi…
The revised Landau hydrodynamic model is used to discuss the pseudorapidity distributions of the produced charged particles in Au+Au and Cu+Cu collisions at energies of sqrt(s_NN)= 19.6 and 22.4 GeV correspondingly on the BNL Relativistic Heavy Ion Collider. It is found that the revised Landau hydrodynamic model alone can give a good description to the experimental measurements. This is different from that in the same collisions but at the maximum energy of sqrt(s_NN)= 200 GeV. Where, in addition to the revised Landau hydrodynamic model, the effects of leading particles have to be taken into a…
In very high energy collisions nuclei are practically transparent to each other but produce very hot, nearly baryon-free, matter in the so-called central rapidity region. The energy in the central rapidity region comes from the kinetic energy of the colliding nuclei. We calculate the energy and rapidity loss of the nuclei using the color glass condensate model. This model also predicts the excitation energy of the nuclear fragments. Using a space-time picture of the collision we calculate the baryon and energy densities of the receding baryonic fireballs. For central collisions of gold nuclei …
Following the Boz$\dot{\textrm{e}}$k-Wyskiel parametrization tilted initial condition, an alternative way to construct a longitudinal tilted fireball based on the Glauber collision geometry is presented. This longitudinal tilted initial condition combined with the Ideal-CLVisc (3 + 1)D hydrodynamic model, a nonvanishing directed flow coefficient $v_{1}$ in a wide rapidity range is observed. After comparing the model's results with experimentally observed data of directed flow coefficient $v_{1}(η)$ from $\sqrt{s_{NN}}$ = 200 GeV Cu + Cu, Au + Au collisions at RHIC energy to $\sqrt{s_{NN}}$ = 2…
Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at 200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be 1.37 +- 0.02(stat) +0.06-0.07(syst), independent of pt.
Within the framework of intermittency analysis, a search for critical fluctuations is ongoing to locate the possible critical point in the quantum chromodynamics phase diagram. In this study, self-similar critical fluctuations from a critical Monte Carlo (CMC) model have been incorporated into the cascade ultrarelativistic quantum molecular dynamics (UrQMD) model. This hybrid UrQMD+CMC model exhibits a clear power-law behavior of scaled factorial moment for charged particles in Au+Au collisions at $\sqrt{s_\mathrm{NN}}$ = 7.7-200 GeV. By comparing the UrQMD+CMC model results with those from th…
We argue that measurements of identified-particle elliptic flow in a wide energy range could shed light on the possible phase change in high-energy heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC). When the hadronization process is dominated by quark coalescence, the number-of-constituent-quark (NCQ) scaling for the identified-particle elliptic flow can serve as a probe for studying the strong interacting partonic matter. In the upcoming RHIC low-energy runs, the NCQ scaling behavior may be broken because of the change of the effective degrees of freedom of the hot dense …
We study the nuclear modification of angular and momentum correlations between heavy quark pairs in ultrarelativistic heavy-ion collisions. The evolution of heavy quarks inside the thermalized medium is described via a modified Langevin approach that incorporates both elastic and inelastic interactions with the medium constituents. The spacetime evolution of the fireball is obtained from a (2+1)-dimensional viscous hydrodynamics simulation. The hadronization of heavy quarks is performed utilizing a hybrid model of fragmentation and coalescence. Our results show that the nuclear modification of…
We suggest that the "new form of matter" found just above $T_c$ by RHIC is made up of tightly bound quark-antiquark pairs, essentially 32 chirally restored (more precisely, nearly massless) mesons of the quantum numbers of $π$, $σ$, $ρ$ and $a_1$. Taking the results of lattice gauge simulations (LGS) for the color Coulomb potential from the work of the Bielefeld group and feeding this into a relativistic two-body code, after modifying the heavy-quark lattice results so as to include the velocity-velocity interaction, all ground-state eigenvalues of the 32 mesons go to zero at $T_c$ just as the…
Local density fluctuations near the QCD critical point has been suggested to exhibit a power-law behavior which can be probed by an intermittency analysis on scaled factorial moment (SFM) in relativistic heavy-ion collisions. The collision energy and centrality dependence of the second-order SFMs are systematically investigated in Au $+$ Au collisions at $\sqrt{s_{NN}}$ = 7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV within the UrQMD model. We estimate the noncritical background in the measurement of intermittency and propose a cumulative variable method to effectively remove the background contr…
Hadronic resonances, having very short lifetime, like $\rm{K}^{*0}$, can act as useful probes to understand and estimate lifetime of hadronic phase in ultra-relativistic proton-proton, p--Pb and heavy-ion collisions. Resonances with relatively longer lifetime, like $ϕ$ meson, can serve as a tool to locate the QGP phase boundary. We estimate a lower limit of hadronic phase lifetime in Cu--Cu and Au--Au collisions at RHIC, and in pp, p--Pb and Pb--Pb collisions at different LHC collision energies. Also, we obtain the effective temperature of $ϕ$ meson using Boltzmann-Gibbs Blast-Wave function, w…
The hydrokinetic approach, that incorporates hydrodynamic expansion of the systems formed in A+A collisions and their dynamical decoupling, is applied to restore the initial conditions and space-time picture of the matter evolution in central Au+Au collisions at the top RHIC energy. The analysis is based on the detailed reproduction of the pion and kaon momentum spectra and femtoscopic data in whole interval of the transverse momenta studied by both STAR and PHENIX collaborations. The fitting procedure utilizes the two parameters: the maximal energy density at supposed thermalization time 1 fm…
The charged particles produced in nucleus-nucleus collisions are divided into two parts. One is from the hot and dense matter created in collisions. The other is from leading particles. The hot and dense matter is assumed to expand according to unified hydrodynamics and freezes out into charged particles from a space-like hypersurface with a fixed proper time of Tau_FO.The leading particles are conventionally taken as the particles which inherit the quantum numbers of colliding nucleons and carry off most of incident energy. The rapidity distributions of the charged particles from these two pa…
We study the diffusion of charm and beauty in the early stage of high energy nuclear collisions at RHIC and LHC energies, considering the interaction of these heavy quarks with the evolving Glasma by means of the Wong equations. In comparison with previous works, we add the longitudinal expansion as well as we estimate the effect of energy loss due to gluon radiation. We find that heavy quarks diffuse in the strong transverse color fields in the very early stage (0.2-0.3 fm/c) and this leads to a suppression at low $p_T$ and enhancement at intermediate low $p_T$. The shape of the observed nucl…
The recent net-proton fluctuation results of the STAR (Solenoidal Tracker At RHIC) experiment from beam energy scan (BES) program at the BNL Relativistic Heavy Ion Collider (RHIC) have drawn much attention to exploring the QCD critical point and the nature of deconfinement phase transition. There has been much speculation that the non-monotonic behavior of $κσ^{2}$ of the produced protons around $\sqrt{s_{\rm NN}}$ = 19.6 GeV in the STAR results may be due to the existence of QCD critical point. However, the experimentally measured proton distributions contain protons from heavy resonance deca…
We find that collective flow model which can successfully analyze charged particle distributions at AGS and lower SPS (less than 20Gev/n). but fails to analyze that of at RHIC. The tails of distribution of charged particle at RHIC has a jump from the collective flow model calculation as the energy increases. Thermalization Component Model is presented based on collective flow to study the multiplicity distributions at RHIC in this paper. It is realized that the region of phase space of collective flow can reflect that of thermalization region. By comparing the contributions of particle product…
Different orientations of $α$-clustered carbon nuclei colliding with heavy ions can result in a large variation in the value of anisotropic flow. Thus, photon flow observables from clustered ${\rm^{12}C}$ and ${\rm^{197}Au}$ collisions could be a potential probe to study the `direct photon puzzle'. We calculate the transverse momentum spectra and anisotropic flow coefficients ($v_n$) of thermal photons from collisions of triangular $α$-clustered carbon and gold at $\sqrt{s_{\rm NN}}=200$ GeV at RHIC using a hydrodynamic model framework and compare the results with those obtained from uncluster…
It is shown that the chemical freeze-out parameters obtained at CERN/SPS, BNL/AGS and GSI/SIS energies all correspond to a unique value of 1 GeV for the average energy per hadron.
The charged particles produced in nucleus-nucleus collisions come from leading particles and those frozen out from the hot and dense matter created in collisions. The leading particles are conventionally supposed having Gaussian rapidity distributions normalized to the number of participants. The hot and dense matter is assumed to expand according to the unified hydrodynamics, a hydro model which unifies the features of Landau and Hwa-Bjorken model, and freeze out into charged particles from a space-like hypersurface with a proper time of Tau_FO . The rapidity distribution of this part of char…
The features of net baryon productions and collective flow in relativistic heavy-ion collisions at energies reached at the CERN Large Hadron Collider (LHC), BNL Relativistic Heavy Ion Collider (RHIC), CERN Super Proton Synchrotron (SPS) and BNL Alternating Gradient Synchrotron (AGS) with the model of Non-Uniform Flow Model(NUFM) are systematically studied in this paper. Especially we predict the feature of net baryon productions and collective flow at LHC $\sqrt{s_{NN}}$=5500 GeV basing on the detailed study of that at RHIC $\sqrt{s_{NN}}$=62.4 and 200GeV. The dependencies of the features of b…
We argue that the transverse mass spectra of identified hadrons as measured in gold-gold collisions at BNL's Relativistic Heavy-Ion Collider (RHIC) follows a generalized scaling law. Such a scaling behavior is motivated by the idea of a Color Glass Condensate, or more generally, saturation of the gluon density. In particular, we describe the shapes of transverse mass spectra as a function of centrality. This scaling of the transverse mass spectrum is shown to be consistent with previously observed scaling of multiplicity with centrality.
We discuss the use of the hydrodynamic model for the description of the evolution of dense matter formed in ultrarelativistic heavy-ion collisions. The collective flow observed in heavy-ion collisions at the BNL Relativistic Heavy Ion Collider and at the CERN Large Hadron Collider is consistent with the assumption that a fireball of strongly interacting matter is formed. Experimental results from p-Pb and d-Au collisions show similar phenomena, which suggests that collective expansion appears in small systems as well. We review the recent application of the hydrodynamic model to small systems …
This White Paper presents the science case of an Electron-Ion Collider (EIC), focused on the structure and interactions of gluon-dominated matter, with the intent to articulate it to the broader nuclear science community. It was commissioned by the managements of Brookhaven National Laboratory (BNL) and Thomas Jefferson National Accelerator Facility (JLab) with the objective of presenting a summary of scientific opportunities and goals of the EIC as a follow-up to the 2007 NSAC Long Range plan. This document is a culmination of a community-wide effort in nuclear science following a series of w…
Centrality, rapidity, and transverse momentum dependence of hadron elliptic flow is studied in Au+Au collisions at BNL RHIC energies within the microscopic quark-gluon string model. The QGSM predictions coincide well with the experimental data at $\sqrt{s}=130$ AGeV. Further investigations reveal that multi-Pomeron exchanges and hard gluon-gluon scattering in primary collisions, accompanied by the rescattering of hadrons in spatially anisotropic system, are the key processes needed for an adequate description of the data. These processes become essentially important for heavy-ion collisions at…
We study the production of bottom quarks in $pp$ collisions at Large Hadron Collider energies using previously developed parton cascade model to explore the impact of Landau Pomeranchuk Midgal (LPM) effect on their dynamics. In contrast to the case for charm quarks reported recently, we find only a marginal impact of the suppression of multiple scatterings of partons due to the LPM effect on their production. It is felt that this happens as they are only produced in very hard collisions.
Dilepton production in heavy-ion collisions at collider energies - i.e., for the Relativistic Heavy-Ion Collider (RHIC) and the Large Hadron Collider (LHC) - is studied within an approach that uses coarse-grained transport simulations to calculate thermal dilepton emission applying in-medium spectral functions from hadronic many-body theory and partonic production rates based on lattice calculations. The microscopic output from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model is hereby put on a grid of space-time cells which allows to extract the local temperature and chemical p…
At Large Hadron Collider energy, the expected large multiplicities suggests the presence of collective behavior even in pp collisions. A hydrodynamical approach has been applied to estimate the expected elliptic flow measured by the azimuthal asymmetry parameter $v_2$, in pp collisions at $\surd$s = 14 TeV. $v_2$ of $π^-$ is found to be strongly dependent on the parton density profile inside a proton [e.g., surface diffuseness parameter ($ξ$)]. For $ξ$ = 0.105, $v_2$ is found to be positive while at $ξ$ = 0.25, $v_2$ is close to zero and approaches negative values at large $p_t$. The impact pa…
We present a factorization formalism for inclusive production of heavy quarkonia of large transverse momentum, $p_T$ at collider energies, including both leading power (LP) and next-to-leading power (NLP) behavior in $p_T$. We demonstrate that both LP and NLP contributions can be factorized in terms of perturbatively calculable short-distance partonic coefficient functions and universal non-perturbative fragmentation functions, and derive the evolution equations that are implied by the factorization. We identify projection operators for all channels of the factorized LP and NLP infrared safe s…
The change of hadron properties in dense matter based on various theoretical approaches are reviewed. Incorporating these medium effects in the relativistic transport model, which treats consistently the change of hadron masses and energies in dense matter via the scalar and vector fields, heavy-ion collisions at energies available from SIS/GSI, AGS/BNL, and SPS/CERN are studied. This model is seen to provide satisfactory explanations for the observed enhancement of kaon, antikaon, and antiproton yields as well as soft pions in the transverse direction from the SIS experiments. In the AGS heav…
I present a short review of recent studies of quarkonium production in proton-proton and proton-nucleus collisions at collider energies in Small-$x$ formalism.
The meson production cross sections are estimated considering photon-photon interactions in hadron - hadron collisions at CERN LHC energies. We consider a large number of mesons with photon-photon partial decay width well constrained by the experiment and some mesons which are currently considered as hadronic molecule and glueball candidates. Our results demonstrate that the experimental analysis of these states is feasible at CERN - LHC.
We study in details the space-time dependence of the production of muonic, pionic, and other exotic atoms by the coherent photon exchange between nuclei at the Large Hadron Collider at CERN. We show that a multipole expansion of the electromagnetic interaction yields an useful insight of the bound-free production mechanism which has not been explored in the literature. Predictions for the spatial, temporal, and angular distribution, as well as the total cross sections, for the production of exotic atoms are also included.
We review the theoretical and experimental progress in the Glauber model of multiple nucleon and/or parton scatterings, after the last 10--15 years of operation with proton and nuclear beams at the CERN Large Hadron Collider (LHC) and with various light and heavy colliding ions at the BNL Relativistic Heavy Ion Collider (RHIC). The main developments and the state-of-the-art of the field are summarized. These encompass measurements of the inclusive inelastic proton and nuclear cross sections, advances in the description of the proton and nuclear density profiles and their fluctuations, inclusio…
We employ a small $x$ Color Glass Condensate (CGC)+ Non-Relativistic QCD (NRQCD) formalism to compute $J/ψ$ production at low $p_\perp$ in proton-proton collisions at collider energies. Very good agreement is obtained for total cross-sections, rapidity distributions and low momentum $p_\perp$ distributions. Similar agreement is obtained for $ψ^\prime$ production. We observe an overlap region in $p_\perp$ where our results match smoothly to those obtained in a next-to-leading order (NLO) collinearly factorized NRQCD formalism. The relative contribution of color singlet and color octet contribut…
We present the mini-proceedings of the workshop on ``Photoproduction at collider energies: from RHIC and HERA to the LHC'' held at the European Centre for Theoretical Studies in Nuclear Physics and Related Areas (ECT*, Trento) from January 15 to 19, 2007. The workshop gathered both theorists and experimentalists to discuss the current status of investigations of high-energy photon-induced processes at different colliders (HERA, RHIC, and Tevatron) as well as preparations for extension of these studies at the LHC. The main physics topics covered were: (i) small-$x$ QCD in photoproduction studie…
Meson production cross sections in ultra-peripheral relativistic heavy ion collisions at LHC are revisited. The relevance of meson models and of exotic QCD states is discussed. This study includes states that have not been considered before in the literature.
In order to have a better understanding of the matter formed in ultra-relativistic collisions, we estimate the jet transport coefficient, $\hat q$, within the Color Sting Percolation Model (CSPM) for various multiplicity classes in proton-proton collisions and centrality classes in nucleus-nucleus collisions at the Large Hadron Collider energies. We study $\hat q$ as a function of final state charged-particle multiplicity and initial percolation temperature. Finally, we compare our obtained results with those calculated from the JET collaboration.
It is shown that the chemical freeze-out parameters obtained at CERN/SPS, BNL/AGS and GSI/SIS energies all correspond to a unique value of 1 GeV per hadron in the local rest frame of the system, independent of the beam energy and of the target and beam particles.
A simultaneous blast-wave fit to particle yields and elliptic flow ($v_{2}$) measured as a function of transverse momentum in Pb-Pb collisions at LHC energies is presented. A compact formula for the calculation of $v_2(p_T)$ for an elliptic freeze-out surface is used which follows from the Cooper-Frye ansatz without further assumptions. Over the full available $p_T$ range, the $Υ$ elliptic flow data is described by the prediction based on the fit to lighter particles. This prediction shows that, due to the large $Υ$ mass, a sizable elliptic flow is only expected at transverse momenta above 10 …
The formation of dibaryons with strangeness are discussed for the interior of neutron stars and for central relativistic heavy-ion collisions. We derive limits for the properties of H-dibaryons from pulsar data. Signals for the formation of possible bound states with hyperons at BNL's Relativistic Heavy-Ion Collider (RHIC) are investigated by studying their weak decay patterns and production rates.
The space-time dynamics and pion-HBT radii in central heavy ion-collisions at CERN-SPS and BNL-RHIC are investigated within a hydrodynamic simulation. The dependence of the dynamics and the HBT-parameters on the EoS is studied with different parametrisations of a chiral SU(3) sigma-omega model. The selfconsistent collective expansion includes the effects of effective hadron masses, generated by the nonstrange and strange scalar condensates. Different chiral EoS show different types of phase transitions and even a crossover. The influence of the order of the phase transition and of the differen…
Nuclei are nearly transparent to each other when they collide at high energy, but the collisions do produce high energy density matter in the central rapidity region where most experimental measurements are made. What happens to the receding nuclear fireballs? We calculate the energy loss of the nuclei using the color glass condensate model. We then use a simple space-time picture of the collision to calculate the baryon and energy densities of the receding fireballs. For central collisions of large nuclei at the BNL Relativistic Heavy Ion Collider and the CERN Large Hadron Collider we find ba…
Within the color string percolation model (CSPM), jet transport coefficient, $\hat{q}$, is calculated for various multiplicity classes in proton-proton and centrality classes in nucleus-nucleus collisions at the Large Hadron Collider energies for a better understanding of the matter formed in ultra-relativistic collisions. $\hat{q}$ is studied as a function of final state charged particle multiplicity (pseudorapiditydensity at midrapidity), initial state percolation temperature and energy density. The CSPM results are then compared with different theoretical calculations from the JET Collabora…
We study the impact of the Landau Pomeranchuk Midgal (LPM) effect on the dynamics of parton interactions in proton proton collisions at the Large Hadron Collider energies. For our investigation we utilize a microscopic kinetic theory based on the Boltzmann equation. The calculation traces the space-time evolution of the cascading partons interacting via semihard pQCD scatterings and fragmentations. We focus on the impact of the LPM effect on the production of charm quarks, since their production is exclusively governed by processes well described in our kinetic theory. The LPM effect is found …
