论文标题
在Atlas的5.02 TEV的中心性依赖性$ p $+pb碰撞中对喷气淬火的强大限制
Strong constraints on jet quenching in centrality-dependent $p$+Pb collisions at 5.02 TeV from ATLAS
论文作者
论文摘要
喷气淬火是通过与重型离子碰撞中产生的夸克 - 胶子等离子体液滴相互作用而失去能量的过程。粘性流体动力学很好地描述了这种液滴的集体扩张。在较小的碰撞系统（包括$ pp $和$ p $+pb碰撞）中始终观察到类似的集体证据。相比之下，尽管在PB+PB碰撞中观察到喷射淬火，但迄今为止这些小型系统尚未发现证据，从而提出了有关这些碰撞中产生的系统性质的基本问题。大型强子撞机的ATLAS实验测量了与重建的Jets相关的$ p $+PB的重建Jets的产量与重建的Jets相关，$ P $+PB和3.6 pb $^{ - 1} $ $ pp $ collisions at 5.02 tev。带有$ p_ \ mathrm {t}^\ mathrm {ch}> 0.5 $ gev在Azimuth中和相反的jets $ p_ \ mathrm {t}^\ mathrm {jet}> 30 $或$ 60 $ gev和$ pb $ pb $ pb的比率的$ p_ mathrm {t}报告了$ i_ {p \ mathrm {pb}} $。 $ p $+PB事件的碰撞中心性由撞击核的正向中子沉积的能量分类。 $ i_ {p \ mathrm {pb}} $ values与具有$ p_ \ mathrm {t}^\ mathrm {ch}> 4 $ gev在所有中心的Hadron的统一性一致。这些数据提供了新的，强大的约束，这些限制几乎排除了中央$ p $+pb碰撞中的任何帕顿能量损失。
Jet quenching is the process of color-charged partons losing energy via interactions with quark-gluon plasma droplets created in heavy-ion collisions. The collective expansion of such droplets is well described by viscous hydrodynamics. Similar evidence of collectivity is consistently observed in smaller collision systems, including $pp$ and $p$+Pb collisions. In contrast, while jet quenching is observed in Pb+Pb collisions, no evidence has been found in these small systems to date, raising fundamental questions about the nature of the system created in these collisions. The ATLAS experiment at the Large Hadron Collider has measured the yield of charged hadrons correlated with reconstructed jets in 0.36 nb$^{-1}$ of $p$+Pb and 3.6 pb$^{-1}$ of $pp$ collisions at 5.02 TeV. The yields of charged hadrons with $p_\mathrm{T}^\mathrm{ch} >0.5$ GeV near and opposite in azimuth to jets with $p_\mathrm{T}^\mathrm{jet} > 30$ or $60$ GeV, and the ratios of these yields between $p$+Pb and $pp$ collisions, $I_{p\mathrm{Pb}}$, are reported. The collision centrality of $p$+Pb events is categorized by the energy deposited by forward neutrons from the struck nucleus. The $I_{p\mathrm{Pb}}$ values are consistent with unity within a few percent for hadrons with $p_\mathrm{T}^\mathrm{ch} >4$ GeV at all centralities. These data provide new, strong constraints which preclude almost any parton energy loss in central $p$+Pb collisions.
