The transverse momentum spectra of hadrons are calculated from the unintegrated gluon distribution (UGD) within the $k_T$-factorization framework at small $x$. Starting from $pp$ collisions, the modification caused by the nuclear medium is incorporated in the UGD at high energies, which is related to the nuclear shadowing phenomenon. Moreover, we consider that particle production from minijet decay is not enough to explain the $p_T$ spectra in $AA$ collisions due to collective phenomena that take place after the hard collision. The Boltzmann-Gibbs blast wave distribution is utilized in order to evaluate the distribution of particle production in equilibrium. Data from the ALICE Collaboration for PbPb collisions at $\sqrt{s}=2.76\mathrm{TeV}$ are analyzed, and the nuclear modification factor for pion production is computed.

中文翻译：

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核胶子分布在重离子碰撞中对颗粒产生的作用

强子的横向动量谱由原子内的非积分胶子分布（UGD）计算。 ${ķ}_{Ť}$小型分解框架 $X$。从...开始$pp$发生碰撞时，由核介质引起的变质在高能下掺入到UGD中，这与核遮蔽现象有关。此外，我们认为微型喷气机衰减产生的颗粒不足以解释$p_{Ť}$ 光谱中 $\mathrm{一种}\mathrm{一种}$硬碰撞后发生的集体现象导致的碰撞。利用Boltzmann-Gibbs爆炸波分布来评估平衡状态下颗粒产生的分布。来自ALICE Collaboration的PbPb碰撞数据$\sqrt{s}=2.76\mathrm{电视}$ 进行分析，并计算出产生介子的核修饰因子。