论文标题
通过角和动量基于恒星的基于动量的差速器测量来限制Parton的能量损失
Constraining parton energy loss via angular and momentum based differential jet measurements at STAR
论文作者
论文摘要
由于最早的RHIC测量结果表明在高$ p _ {\ rm {t}} $和巧合的收益率时，Parton的能量损失已成为重离子碰撞中夸克 - 胶子血浆（QGP）的重要签名。了解这种淬灭的现象是通过喷射 - 托马学提取QGP的微观特性的必要条件。 Star最近推出了一种称为Jet Goemetry Engineering（JGE）的技术，其中我们强制对喷气系列施加的特定选择标准，例如退出高$ P _ {\ rm {t}} $ HADRON触发器，以及与背靠背型组成的额外的横向动量阈值一起，与背靠背di-di-di-di-di-di-di-jets的evestect evest。借助JGE，我们能够控制从猝灭/失衡到恢复/平衡的DI-JET的能量损失程度。由于射流淬火还有望取决于射流探测介质的分辨率/横向长度，因此有必要在动量和角度尺度上使用手柄进行微分测量。要量化喷气机中的角度尺度，我们介绍了$ \ sqrt {s _ {s _ {\ mathrm {nn}}} = $ 200 GEV的au $+$ au碰撞中喷气机固有的角结构的第一个测量，这是通过两个领先的subl-jets之间的开头（$θ__{$θ__{sj} $ rmm {sj}。我们还要测量DI-JET不对称$ a _ {\ rm {j}} $差异地作为这些DI-JET的$θ_ {\ rm {sj}} $的函数，对于这些DI-JETS可观察到，并且在后退射流射流的开放角度上无明显的能量损失依赖性。
Parton energy loss has been established as an essential signature of the Quark-Gluon Plasma (QGP) in heavy ion collisions since the earliest measurements at RHIC indicating suppression of hadron spectra at high $p_{\rm{T}}$ and coincidence yields. Understanding this phenomenon of jet quenching is a requirement for extracting the microscopic properties of the QGP via jet-tomography. STAR has recently introduced a technique called Jet Geometry Engineering (JGE) wherein we enforce particular selection criteria imposed on the jet collection, such as recoiling off a high $p_{\rm{T}}$ hadron trigger along with an additional transverse momentum threshold for jet constituents in events with back-to-back di-jets. With JGE, we are able to control the extent of energy loss ranging from quenched/imbalanced to recovered/balanced di-jets. Since jet quenching is also expected to be dependent on the resolution/transverse-length scales with which the jet probes the medium, it is necessary to perform differential measurements with a handle on both momentum and angular scales. To quantify the angular scale within jets, we present the first measurement of the jet's inherent angular structure in Au$+$Au collisions at $\sqrt{s_{\mathrm{NN}}} = $ 200 GeV via the opening angle between the two leading sub-jets ($θ_{\rm{SJ}}$). We also measure the di-jet asymmetry $A_{\rm{J}}$ differentially as a function of the $θ_{\rm{SJ}}$ observable for these di-jets and find no significant dependence of the energy loss on the opening angle of the recoil jet.
