AI 中文总结
本研究利用ATLAS探测器，在√s_NN=5.02 TeV的Pb+Pb与pp碰撞中首次测量了向前快度区间的包含喷注压低，获得了喷注核修正因子，为部分子能量损失的相关性质提供了新约束。
AI 中文摘要
利用LHC的ATLAS探测器，对质心系能量√s_NN=5.02 TeV的Pb+Pb和pp碰撞中的包含喷注产生进行了测量，所用数据样本对应的积分亮度分别为1.72 nb⁻¹和255 pb⁻¹。针对反k_t喷注（半径参数R=0.4），在向前快度区间2.8<|y|<3.2和3.2<|y|<3.6中报告了喷注核修正因子R_AA，探测的横动量p_T>74 GeV。观测到的R_AA值显示，与pp碰撞相比，Pb+Pb碰撞中的喷注产额存在显著压低；这种压低从周边碰撞到中心碰撞单调增加，且呈现出轻微的喷注p_T依赖性。与ATLAS此前的测量结果对比表明，2.8<|y|<3.2区域的喷注压低强于|y|<2.8区域；而在3.2<|y|<3.6区域，测量精度不足以与|y|<2.8区域进行确定性对比。这些结果是重离子碰撞中向前快度区间包含喷注压低的首次测量，为部分子能量损失的味、几何和介质密度依赖性提供了新的约束。
英文摘要
Inclusive jet production is measured with the ATLAS detector at the LHC at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV in Pb+Pb and $pp$ collisions, using data samples corresponding to integrated luminosities of 1.72 nb$^{-1}$ and 255 pb$^{-1}$, respectively. The jet nuclear modification factor, $R_{\mathrm{AA}}$, is reported for anti-$k_t$ jets with radius parameter $R=0.4$ in the forward-rapidity intervals $2.8<|y|<3.2$ and $3.2<|y|<3.6$, probing transverse momenta $p_\mathrm{T}>74$ GeV. The observed $R_{\mathrm{AA}}$ values show a significant suppression of jet yields in Pb+Pb collisions relative to those measured in $pp$ collisions. The suppression increases monotonically from peripheral to central collisions and exhibits a mild jet $p_\mathrm{T}$ dependence. A comparison with previous ATLAS measurements indicates stronger jet suppression in the $2.8<|y|<3.2$ region than in the $|y| < 2.8$ region. In the $3.2<|y|<3.6$ region, the precision of the measurement does not allow a conclusive comparison with the $|y|<2.8$ region. These results constitute the first measurement of inclusive jet suppression at forward rapidity in heavy-ion collisions and provide new constraints on flavor, geometric, and medium-density dependence of parton energy loss.
Comments37 pages in total, author list starting page 20, 2 tables, 6 figures, submitted to Phys. Lett. B. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HION-2023-11
