Violation of Wiedemann-Franz Law for Hot Hadronic Matter created at NICA, FAIR and RHIC Energies using Non-extensive Statistics

We present here the computation of electrical and thermal conductivity by solving the Boltzmann transport equation in relaxation time approximation. We use the $q$-generalized Boltzmann distribution function to incorporate the effects of non-extensivity. The behaviour of these quantities with changing temperature and baryochemical potential has been studied as the system slowly moves towards thermodynamic equilibrium. We have estimated the Lorenz number at NICA, FAIR and the top RHIC energies and studied as a function of temperature, baryochemical potential and the non-extensive parameter, $q$. We have observed that Wiedemann-Franz law is violated for a non-extensive hadronic phase as well as for an equilibrated hadron gas at high temperatures.Comment: Same as the published versio

Centrality dependence of Electrical and Hall conductivity at RHIC and LHC energies for a Conformal System

In this work, we study electrical conductivity and Hall conductivity in the presence of electromagnetic field using Relativistic Boltzmann Transport Equation with Relaxation Time Approximation. We evaluate these transport coefficients for a strongly interacting system consisting of nearly massless particles which is similar to Quark-Gluon Plasma and is likely to be formed in heavy-ion collision experiments. We explicitly include the effects of magnetic field in the calculation of relaxation time. The values of magnetic field are obtained for all the centrality classes of Au+Au collisions at $\sqrt {s_{\rm NN}} =$ 200 GeV and Pb+Pb collisions at $\sqrt {s_{\rm NN}} =$ 2.76 TeV. We consider the three lightest quark flavors and their corresponding antiparticles in this study. We estimate the temperature dependence of the electrical conductivity and Hall conductivity for different strengths of magnetic field. We observe a significant dependence of temperature on electrical and Hall conductivity in the presence of magnetic field.Comment: Same as the published version in EPJ

Role of chemical potential at kinetic freeze-out using Tsallis non-extensive statistics in proton-proton collisions at the Large Hadron Collider

The charged-particle transverse momentum spectra ($p_{\rm T}$-spectra) measured by the ALICE collaboration for $pp$ collisions at $\sqrt {s} =$ 7 and 13 TeV have been studied using a thermodynamically consistent form of Tsallis non-extensive statistics. The Tsallis distribution function is fitted to the $p_{\rm T}$-spectra and the results are analyzed as a function of final state charged-particle multiplicity for various light flavor and strange particles, such as $\pi^{\pm}, K^{\pm}, p+\bar{p}, \phi, \Lambda+\bar{\Lambda}, \Xi+\bar{\Xi}, \Omega+\bar{\Omega}$. At the LHC energies, particles and antiparticles are produced in equal numbers. However, the equality of particle and antiparticle yields at the kinetic freeze-out may imply that they have the same but opposite chemical potential which is not necessarily zero. We use an alternative procedure that makes use of parameter redundancy, by introducing a finite chemical potential at the kinetic freeze-out stage. This article emphasizes the importance of the chemical potential of the system produced in $pp$ collisions at the LHC energies using the Tsallis distribution function which brings the system to a single freeze-out scenario.Comment: Same as the published version in EPJ

Insight into K∗(892)0{K}^*(892)^{0} production in pp collisions as a function of collision energy, event-topology, and multiplicity with ALICE at the LHC

Hadronic resonances are short-lived particles whose lifetimes are comparable to the hadronic phase lifetime of the system produced in ultra-relativistic nucleon$-$nucleon or nuclear collisions. These resonances are sensitive to the hadronic phase effects such as re-scattering and regeneration processes which might affect the resonance yields and shape of the transverse momentum spectra. In addition, event shape observables like transverse spherocity are sensitive to the hard and soft processes and they represent a useful tool to separate the isotropic from jetty-dominated events in proton$-$proton (pp) collisions. A double differential study of transverse spherocity and multiplicity allows us to understand the resonance production mechanism with event topology and system size, respectively. Furthermore, the measurements in small systems are used as a reference for heavy-ion collisions and are helpful for the tuning of Quantum Chromodynamics (QCD) inspired event generators. In this proceeding, we present recent results on $\rm{K}^*(892)^{0}$ obtained by the ALICE Collaboration in pp collisions at several collision energies, event multiplicities, and as a function of transverse spherocity. The results include the transverse momentum spectra, yields, and their ratio to long-lived particles. The measurements are compared with model predictions from PYTHIA8, EPOS-LHC, and DIPSY

A Baseline Study of the Event-Shape and Multiplicity Dependence of Chemical Freeze-Out Parameters in Proton-Proton Collisions at ( {sqrt{s}} ) = 13 TeV Using PYTHIA8

The event-shape and multiplicity dependence of the chemical freeze-out temperature (Tch), freeze-out radius (R), and strangeness saturation factor (γs) are obtained by studying the particle yields from the PYTHIA8 Monte Carlo event generator in proton-proton (pp) collisions at the centre-of-mass s = 13 TeV. Spherocity is one of the transverse event-shape techniques to distinguish jetty and isotropic events in high-energy collisions and helps in looking into various observables in a more differential manner. In this study, spherocity classes are divided into three categories, namely (i) spherocity integrated, (ii) isotropic, and (iii) jetty. The chemical freeze-out parameters are extracted using a statistical thermal model as a function of the spherocity class and charged particle multiplicity in the canonical, strangeness canonical, and grand canonical ensembles. A clear observation of the multiplicity and spherocity class dependence of Tch, R, and γs is observed. A final state multiplicity, Nch≥ 30 in the forward multiplicity acceptance of the ALICE detector appears to be a thermodynamic limit, where the freeze-out parameters become almost independent of the ensembles. This study plays an important role in understanding the particle production mechanism in high-multiplicity pp collisions at the Large Hadron Collider (LHC) energies in view of a finite hadronic phase lifetime in small systems

Insight into the light-flavour particle production mechanism from studies of the transverse spherocity dependence in pp collisions at √s =13 TeV with ALICE at the LHC

The Large Hadron Collider (LHC) Run 1 and Run 2 data revealed heavy-ion-like features such as enhanced strangeness production and long-range azimuthal correlation in high-multiplicity pp collisions paving the way to rethink particle production in small collision systems. Event shape observables like transverse spherocity are sensitive to isotropic and jet-like topologies, which are useful tools to distinguish the pp collisions dominated by soft or hard physics. The interplay between multiplicity and transverse spherocity on light-flavour particle production can be understood by comparing the results obtained by selecting multiplicity and/or transverse spherocity. This contribution presents recent results on light-flavour particle production (π, K, p, ф, K*0, K0s, Λ, ξ) at midrapidity obtained by the ALICE experiment in pp collisions at √s = 13 TeV as a function of event multiplicities and transverse spherocity. The results are even obtained by going to the most extreme selections such as the highest 0–1% in multiplicity and the highest 0–10% in transverse sphe rocity. The results include the transverse momentum spectra, yields, 〈pT〉 and their ratios. These measurements will be compared with the Monte Carlo (MC) predictions obtained from models such as PYTHIA8, EPOS and Herwig7

Event topology and multiplicity dependence of K∗(892)0\rm{K}^{∗}(892)^{0} production in proton+proton collisions with ALICE at the LHC and probing TeV collisions through particle production and transport properties

In this thesis, we have studied the effect of event-topology (transverse spherocity) on the production of $\rm{K}^{∗}(892)^{0}$ resonance particle, which has a lifetime of $\sim$10$^{-24}s$. This lifetime is comparable to the hadronic phase lifetime of the system produced in ultra-relativistic nucleon-nucleon or nuclear collisions. $\rm{K}^{∗}(892)^{0}$ is sensitive to the hadronic phase effects such as rescattering and regeneration processes, which might affect the yield and shape of the transverse momentum spectra. In addition, event shape observables like transverse spherocity are sensitive to the hard and soft processes. They are useful tools to distinguish the isotropic and jetty-dominated events in pp collisions. Studying the dependence of the yield of resonance on transverse spherocity and multiplicity allows us to understand the resonance production mechanism with event topology and system size, respectively. In this thesis, we observe that low multiplicity pp collisions are more dominated by jetty-like events whereas high multiplicity pp collisions are highly populated with isotropic-like events. In high multiplicity pp collisions, it is found that the low transverse momentum region is more dominated by isotropic-like events whereas the high transverse momentum region is dominated mostly by jetty-like events. Moreover, we have also studied the integrated yield, mean transverse momentum, and particle ratio to long-lived stable particles. Furthermore, the measurements in small systems done using the ALICE detector are compared with results obtained from models such as PYTHIA8, EPOS-LHC, etc. Also, these results are helpful for the tuning of Quantum Chromodynamics inspired event generators. In this thesis, we have also carried out several phenomenological studies to understand the behaviour of chemical and kinetic freeze-out parameters in pp collisions, the dependence of transport coefficients like thermal conductivity, electrical conductivity, and hall conductivity with temperature, chemical potential, and strength of magnetic field using relativistic Boltzmann transport equation with relaxation time approximation and the particle production in nuclear collisions with deformed Xe nuclei using A Multi-Phase Transport model (AMPT)

Event multiplicity, transverse momentum and energy dependence of charged particle production, and system thermodynamics in pppp collisions at the Large Hadron Collider

In the present work, we study the recent collision energy and multiplicity dependence of the charged particle transverse momentum spectra as measured by the ALICE collaboration in $pp$ collisions at $\sqrt{s}$ = 5.02 and 13 TeV using the non-extensive Tsallis distribution and the Boltzmann-Gibbs Blast Wave (BGBW) model. A thermodynamically consistent form of the Tsallis distribution is used to extract the kinetic freeze-out parameters from the transverse momentum spectra of charged particles at mid-rapidity. In addition, a comprehensive study of fitting range dependence of transverse momentum spectra on the freeze-out parameters is done using Tsallis statistics. The applicability of BGBW model is verified by fitting the transverse momentum spectra of the bulk part ($\sim 2.5~ {\rm GeV}/c$)for both 5.02 and 13 TeV energies and also in different multiplicity classes. The radial flow, $$ is almost independent of collision energy and multiplicity whereas the behavior of kinetic freeze-out temperature significantly depends on multiplicity classes. It is found that the Tsallis distribution generally leads to a better description for the complete transverse momentum spectra whereas the BGBW model explains the bulk part of the system.In the present work, we study the recent collision energy and multiplicity dependence of the charged particle transverse momentum spectra as measured by the ALICE collaboration in pp collisions at and 13 TeV using the non-extensive Tsallis distribution and the Boltzmann–Gibbs blast wave (BGBW) model. A thermodynamically consistent form of the Tsallis distribution is used to extract the kinetic freeze-out parameters from the transverse momentum spectra of charged particles at mid-rapidity. In addition, a comprehensive study of fitting range dependence of transverse momentum spectra on the freeze-out parameters is done using Tsallis statistics. The applicability of BGBW model is verified by fitting the transverse momentum spectra of the bulk part (∼2.5 GeV/c) for both 5.02 and 13 TeV energies and also in different multiplicity classes. The radial flow, is almost independent of collision energy and multiplicity whereas the behavior of kinetic freeze-out temperature significantly depends on multiplicity classes. It is found that the Tsallis distribution generally leads to a better description for the complete transverse momentum spectra whereas the BGBW model explains the bulk part of the system