"Table 28" of "Measurement of jet quenching with semi-inclusive hadron-jet distributions in central Pb-Pb collisions at ${\sqrt{\bf{s}_{\mathrm {\bf{NN}}}}}$ = 2.76 TeV"

CERN-LHC. We report the measurement of a new observable of jet quenching in central Pb-Pb collisions at $\sqrt{s_{\rm NN}} = 2.76$ TeV, based on the semi-inclusive rate of charged jets recoiling from a high transverse momentum (high-$p_{\rm T}$) charged hadron trigger. Jets are measured using collinear-safe jet reconstruction with infrared cutoff for jet constituents of 0.15 GeV/$c$, for jet resolution parameters $R = 0.2$, 0.4 and 0.5. Underlying event background is corrected at the event-ensemble level, without imposing bias on the jet population. Recoil jet spectra are reported in the range $20 < p_\mathrm{T,jet}^\mathrm{ch} < 100$ GeV/$c$. Reference distributions for pp collisions at $\sqrt{s} = 2.76$ TeV are calculated using Monte Carlo and NLO pQCD methods, which are validated by comparing with measurements in pp collisions at $\sqrt{s} = 7$ TeV. The recoil jet yield in central Pb-Pb collisions is found to be suppressed relative to that in pp collisions. No significant medium-induced broadening of the intra-jet energy profile is observed within 0.5 radians relative to the recoil jet axis. The angular distribution of the recoil jet yield relative to the trigger axis is found to be similar in central Pb-Pb and pp collisions, with no significant medium-induced acoplanarity observed. Large-angle jet deflection, which may provide a direct probe of the nature of the quasi-particles in hot QCD matter, is explored.欧洲核子研究中心大型强子对撞机（CERN-LHC）。本研究报道了质心系能量sqrt{s_{ m NN}}=2.76 TeV的中心铅-铅（Pb-Pb）碰撞中一种全新喷注淬火可观测物理量的测量结果，该测量基于从高横动量（high-$p_mathrm{T}$）带电强子触发粒子反冲得到的带电喷注半单举产额。喷注的重建采用共线安全（collinear-safe）的喷注重建算法，喷注组成粒子的红外截断为0.15 GeV/$c$，喷注分辨参数$R$取0.2、0.4和0.5。本研究在事件系综层面修正了underlying事件（underlying event）背景，且未对喷注样本引入任何偏倚。反冲带电喷注的横动量谱测量范围为$20 < p_mathrm{T,jet}^mathrm{ch} < 100$ GeV/$c$。我们通过蒙特卡洛（Monte Carlo）与次领头阶微扰量子色动力学（NLO pQCD）方法计算了质心系能量sqrt{s}=2.76 TeV的质子-质子（pp）碰撞的参考分布，并通过与sqrt{s}=7 TeV质子-质子碰撞的测量结果比对验证了该参考分布的可靠性。研究发现，中心铅-铅碰撞中的反冲喷注产额相较于质子-质子碰撞出现了抑制现象。在反冲喷注轴0.5弧度范围内，未观测到由介质诱导产生的喷注内部能量分布显著展宽现象。相较于触发粒子轴的反冲喷注产额角分布，在中心铅-铅碰撞与质子-质子碰撞中表现出相似性，且未观测到由介质诱导产生的显著非共面性。本研究还探讨了大角度喷注偏转现象，该现象有望直接探测热量子色动力学（QCD）物质中准粒子的本质属性。