使用d+Au碰撞研究纵向熵沉积
Study the Longitudinal Entropy Deposition using d+Au Collision
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中文总结 AI 辅助
研究旨在解决相对论流体动力学在d+Au碰撞中描述带电粒子快度分布的难题。通过对初始状态建模改进，引入新纵向熵沉积模型。利用相关模型模拟碰撞，成功再现多类实验结果，且该框架通用性好，可用于多种碰撞更好约束轻核结构。
中文摘要 AI 辅助
相对论流体动力学成功描述了对称重离子碰撞中的整体可观测量，但在描述非对称系统（如d+Au碰撞）中的带电粒子快度分布时遇到困难。为应对这一挑战，我们对初始状态建模进行了两项关键改进：从从头算波函数中采样氘核构型，并开发了一种新的纵向熵沉积模型，该模型包含横向熵沉积系数β和与二元碰撞数n_BC成比例的快度损失项。使用(3+1)维粘性流体动力学模型CLVisc与SMASH后燃烧器耦合，我们模拟了√s_NN = 200 GeV的d+Au碰撞，并成功再现了五个中心度类别的实验带电粒子赝快度分布，β = 0.35，以及横向动量谱和各向异性流v_n。发现熵沉积系数β和与n_BC相关的快度损失在实现这一一致性方面起着关键作用。此外，该纵向熵沉积框架在p+Au、^3He+Au和Au+Au碰撞中得到验证，具有出色的通用性。我们的熵沉积机制可广泛应用于近期的轻核碰撞，如LHC能量下的O+O、Ne+Ne以及Pb+Ne等非对称系统，从而通过改进的纵向描述更好地约束轻核的核结构。
英文摘要
Relativistic hydrodynamics successfully describes bulk observables in symmetric heavy-ion collisions, but struggles to reproduce charged-particle rapidity distributions in asymmetric systems such as d+Au collisions. To address this challenge, we introduce two key improvements to the initial-state modeling: sampling deuteron configurations from an ab initio wavefunction, and developing a new longitudinal entropy deposition model that incorporates a transverse entropy deposition coefficient $β$ and a rapidity loss term scaling with the number of binary collisions $n_{\rm BC}$. Using the (3+1)-dimensional viscous hydrodynamic model CLVisc coupled with the SMASH afterburner, we simulate d+Au collisions at $\sqrt{s_{\rm NN}} = 200$ GeV and successfully reproduce the experimental charged-particle pseudorapidity distributions across five centrality classes with $β= 0.35$, as well as the transverse momentum spectra and anisotropic flow $v_n$. The entropy deposition coefficient $β$ and the $n_{\rm BC}$-dependent rapidity loss are found to play crucial roles in achieving this agreement. Furthermore, this longitudinal entropy deposition framework demonstrates excellent universality, as validated in p+Au, $^3$He+Au, and Au+Au collisions. Our entropy deposition mechanism could be widely applied to recent light-nucleus collisions such as O+O, Ne+Ne, and asymmetric systems like Pb+Ne at LHC energies, thereby better constraining the nuclear structure of light nuclei through an improved longitudinal description.
