"Table 30" of "Centrality and rapidity dependence of inclusive jet production in $\sqrt{s_\mathrm{NN}} = 5.02$ TeV proton--lead collisions with the ATLAS detector"

CERN-LHC. Measurements of the centrality and rapidity dependence of inclusive jet production in $\sqrt{s_\mathrm{NN}} = 5.02$ TeV proton--lead ($p$+Pb) collisions and the jet cross-section in $\sqrt{s} = 2.76$ TeV proton--proton collisions are presented. These quantities are measured in datasets corresponding to an integrated luminosity of 27.8 nb$^{-1}$ and 4.0 pb$^{-1}$, respectively, recorded with the ATLAS detector at the Large Hadron Collider in 2013. The $p$+Pb collision centrality was characterised using the total transverse energy measured in the pseudorapidity interval $-4.9 < \eta < -3.2$ in the direction of the lead beam. Results are presented for the double-differential per-collision yields as a function of jet rapidity and transverse momentum ($p_\mathrm{T}$) for minimum-bias and centrality-selected $p$+Pb collisions, and are compared to the jet rate from the geometric expectation. The total jet yield in minimum-bias events is slightly enhanced above the expectation in a $p_\mathrm{T}$-dependent manner but is consistent with the expectation within uncertainties. The ratios of jet spectra from different centrality selections show a strong modification of jet production at all $p_\mathrm{T}$ at forward rapidities and for large $p_\mathrm{T}$ at mid-rapidity, which manifests as a suppression of the jet yield in central events and an enhancement in peripheral events. These effects imply that the factorisation between hard and soft processes is violated at an unexpected level in proton--nucleus collisions. Furthermore, the modifications at forward rapidities are found to be a function of the total jet energy only, implying that the violations may have a simple dependence on the hard parton-parton kinematics.

欧洲核子研究中心大型强子对撞机（CERN-LHC）合作组报道了质心系能量√s_NN=5.02 TeV的质子-铅（p+Pb）碰撞中单举喷注产生的中心度与快度依赖关系，以及质心系能量√s=2.76 TeV的质子-质子碰撞的喷注截面测量结果。本次测量使用大型强子对撞机上的ATLAS探测器于2013年采集的数据，对应的积分亮度分别为27.8纳靶恩反（nb⁻¹）和4.0皮靶恩反（pb⁻¹）。质子-铅碰撞的中心度通过铅束流方向上赝快度区间-4.9 < η < -3.2内测得的总横向能量进行标定。研究给出了最小偏置及中心度选择的质子-铅碰撞中，喷注快度与横向动量（transverse momentum, p_T）的函数关系下，每碰撞次的双微分产额，并将结果与几何预期的喷注产率进行对比。最小偏置事件中的总喷注产额随横向动量呈现出依赖于横向动量的小幅超出几何预期的现象，但在误差范围内与几何预期一致。不同中心度选择下的喷注能谱比值显示，前向快度区间内所有横向动量范围、以及中心快度区间内大横向动量范围的喷注产生均被显著修改，表现为中心碰撞中喷注产额被压低、外围碰撞中喷注产额被增强。上述效应表明，质子-原子核碰撞中硬过程与软过程的因子化被以超出预期的程度破坏。进一步研究发现，前向快度区间的修改效应仅与总喷注能量相关，这暗示该因子化破坏现象可能仅依赖于硬部分子-部分子运动学。