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Register a new userStudy of nuclear modification factors of (anti-)hadrons and light (anti-)nuclei in Pb-Pb collisions at $sqrt{s_{rm{NN}}}$ = 2.76 TeV
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The nuclear modification factors ($R_{AA}$) of $pi^{pm}, p(bar p)$, and $d(bar d)$ with $|y|<0.5, p_T<20.0$~GeV/c in peripheral (40-60%) and central (0-5%) Pb-Pb collisions at $sqrt {s_{NN}}=2.76$ TeV have been studied using the parton and hadron cascade ({footnotesize PACIAE}) model plus the dynamically constrained phase space coalescence ({footnotesize DCPC}) model. It is found that the $R_{AA}$ of light (anti)nuclei ($d, bar d$) is similar to that of hadrons ($pi^pm, p, bar p$), and the $R_{AA}$ of antiparticles is the same as that of particles. The suppression of $R_{AA}$ at high-$p_T$ strongly depends on event centrality and mass of the particles, i.e., the central collision is more suppressed than the peripheral collision. Besides, the yield ratios and double ratios for different particle species in $pp$ and Pb-Pb collisions are discussed, respectively. It is observed that the yield ratios and double ratios of $d$ to $p$ and $p$ to $pi$ are similar to those of their anti-particles in three different collision systems, suggesting that the suppressions of matter ($pi^{+}, p, d$) and the corresponding antimatter ($pi^{-},bar{p},bar{d}$) are around the same level.
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Elliptic flow in heavy-ion collisions is an important signature of a possible de-confinement transition from hadronic phase to partonic phase. In the present work, we use non-extensive statistics, which has been used for transverse momentum ($p_{rm T}$) distribution in proton+proton ($p+p$) collisions, as the initial particle distribution function in Boltzmann Transport Equation (BTE). A Boltzmann-Gibbs Blast Wave (BGBW) function is taken as an equilibrium function to get the final distribution to describe the particle production in heavy-ion collisions. In this formalism, we try to estimate the elliptic flow in Pb+Pb collisions at $sqrt{s_{rm NN}}$ = 2.76 TeV at the LHC for different centralities. The elliptic flow ($v_2$) of identified particles seems to be described quite well in the available $p_{rm T}$ range. An approach, which combines the non-extensive nature of particle production in $p+p$ collisions through an evolution in kinetic theory using BTE, with BGBW equilibrium distribution is successful in describing the spectra and elliptic flow in heavy-ion collisions.
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