发表机构
University of Cape Town; New Mexico State University; Okinawa Institute of Science and Technology Graduate University; Brookhaven National Laboratory（开普敦大学; 新墨西哥州立大学; 冲绳科学技术大学院大学; 布鲁海文国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
基于IP-Glasma框架，预测了多种碰撞系统中仅由初始态效应导致的核修正因子，并发现硬-软关联源于色场的事件涨落，同时解释了实验中的抑制现象。
AI 中文摘要
我们首次给出了基于饱和物理框架IP-Glasma对核修正因子$R_{AB}$作为中心度函数的预测，该预测仅考虑初始态效应，适用于$p$+O、$p$+Pb、O+O和Pb+Pb碰撞。同一框架同时负责软（$p_T \lesssim 3 ~\mathrm{GeV}$）和半硬（$5 ~\mathrm{GeV} \lesssim p_T \lesssim 20 ~\mathrm{GeV}$）粒子的产生，从而能够从第一性原理框架研究体粒子产生与中等$p_T$粒子产生之间的初始态关联。我们表明，仅通过HERA数据调优，IP-Glasma就能准确预测$p$+O、$p$+Pb、O+O和Pb+Pb碰撞中的自归一化多重数分布；$p$+O和$p$+Pb碰撞中的最小偏置核修正因子；$p$+Pb碰撞中的中心度截断核修正因子；以及在Pb+Pb碰撞中观测到的非常外围事件的$R_{AA}$反常抑制。我们发现，IP-Glasma预测的抑制程度显著低于大型强子对撞机在$\sqrt{s_{NN}} = 5.36 ~\mathrm{TeV}$的O+O和$\sqrt{s_{NN}} = 5.02 ~\mathrm{TeV}$的Pb+Pb碰撞中测得的抑制，这与$R_{AA} < 1$归因于末态能量损失的定性情景一致。我们表明，IP-Glasma产生的非弹性核子-核子截面（$\sigma_{\text{inel}}^{NN}$）对亚核子热点的面积极其敏感；能够重现所测$\sigma_{\text{inel}}^{NN}$的相同热点面积值也能重现最小偏置$R_{pA}$。最后，我们表明IP-Glasma中的硬-软关联源于色场的事件-by-事件涨落，这些涨落同时驱动软和硬粒子产生的增强。
英文摘要
We present first predictions from the saturation-physics-based framework IP-Glasma for the nuclear modification factor $R_{AB}$ as a function of centrality in $p$ + O, $p$ + Pb, O + O, and Pb + Pb collisions due only to initial-state effects. The same framework is responsible for both soft ($p_T \lesssim 3 ~\mathrm{GeV}$) and semi-hard ($5 ~\mathrm{GeV} \lesssim p_T \lesssim 20 ~\mathrm{GeV}$) particle production, enabling the study of initial-state correlations between bulk and intermediate-$p_T$ particle production from a first-principles framework. We show that, tuned only to HERA data, IP-Glasma accurately predicts the self-normalized multiplicity distributions in $p$ + O, $p$ + Pb, O + O, and Pb + Pb collisions; the minimum-bias nuclear modification factor in $p$ + O and $p$ + Pb collisions; the centrality-cut nuclear modification factor in $p$ + Pb collisions; and the anomalous suppression of $R_{AA}$ observed in very peripheral Pb + Pb collisions. We find that IP-Glasma predicts significantly less suppression than is measured in both $\sqrt{s_{NN}} = 5.36 ~\mathrm{TeV}$ O + O and $\sqrt{s_{NN}} = 5.02 ~\mathrm{TeV}$ Pb + Pb collisions at the Large Hadron Collider, in qualitative agreement with the scenario in which $R_{AA} < 1$ is due to final-state energy loss. We show that the inelastic nucleon-nucleon cross section ($σ_{\text{inel}}^{NN}$) produced by IP-Glasma is extremely sensitive to the area of the subnucleonic hotspots; the same values of the hotspot area that reproduce the measured $σ_{\text{inel}}^{NN}$ also reproduce minimum-bias $R_{pA}$. Finally, we show that the hard-soft correlations in IP-Glasma arise from event-by-event fluctuations in the color fields, which simultaneously drive enhanced production of both soft and hard particles.
Comments30 pages, 22 figures
