论文标题
PB-PB和P-PB碰撞中使用Boltzmann传输方程式的核修饰因子
Nuclear modification factor in Pb-Pb and p-Pb collisions using Boltzmann transport equation
论文作者
论文摘要
我们调查了已识别粒子的核修饰因子（$ r_ {aa} $）在$ \ sqrt {s _ {\ s_ {\ rm nn}}} = $ 2.76和5.02 tev的pb-pb碰撞中，在$ \ sqrt {s _ {s _ {s _ {s s _ {s s _ {放松时间近似的方程式。在此框架中，选择颗粒的初始分布作为tsallis分布和局部平衡分布作为玻尔兹曼·吉布斯爆炸波分布。非扩展参数$ q_ {pp} $，tsallis温度$ t_ {pp} $和平衡温度$ t_ {eq} $的共同点是所有粒子的共同点给定中心的不同颗粒。我们观察到，拟合曲线描述了最高$ p _ {\ rm t} \ $ 3 gev/c的光谱。 $ q_ {pp} $和$ t_ {eq} $（$ t_ {f}/τ$）降低（增加），而中心性则非线性，而$ t_ {pp} $几乎独立于中心性。 $ q_ {pp} $，$ t_ {eq} $或$ t_ {f}/τ$随着中心度的变化而对碰撞系统的能量和大小的中心性变化的速率的依赖性。
We investigate the nuclear modification factor ($R_{AA}$) of identified particles as a function of transverse momentum ($p_{\rm T}$) in Pb-Pb collisions at $\sqrt{s_{\rm NN}}=$ 2.76 and 5.02 TeV, as well as p-Pb collision at 5.02 TeV in the framework of Boltzmann transport equation with relaxation time approximation. In this framework, the initial distribution of particles is chosen as the Tsallis distribution and the local equilibrium distribution as the Boltzmann-Gibbs blast-wave distribution. The non-extensive parameter $q_{pp}$, the Tsallis temperature $T_{pp}$ and the equilibrium temperature $T_{eq}$ are set to be in common for all particles, while the ratio of kinetic freeze-out time to relaxation time $t_{f}/τ$ is different for different particles when we performed a combined fit to the $R_{AA}$ spectra of different particles at a given centrality. We observe that the fitted curves describe the spectra well up to $p_{\rm T}\approx$ 3 GeV/c. $q_{pp}$ and $T_{eq}$ ($t_{f}/τ$) decrease (increases) with centrality nonlinearly, while $T_{pp}$ is almost independent of centrality. The dependence of the rate at which $q_{pp}$, $T_{eq}$ or $t_{f}/τ$ changes with centrality on the energy and the size of the colliding system is discussed.
