"jfs_00-20 4-7 x 3-4" of "Suppression of away-side jet fragments with respect to the reaction plane in Au+Au collisions at sqrt(s_NN) = 200 GeV"

BNL-RHIC. Pair correlations between large transverse momentum neutral pion triggers (pT= 4–7 GeV/c) andcharged hadron partners (pT= 3–7 GeV/c) in central (0–20%) and midcentral (20–60%) Au+Aucollisions are presented as a function of trigger orientation with respect to the reaction plane. Theparticles are at larger momentum than where jet shape modifications have been observed, and thecorrelations are sensitive to the energy loss of partons traveling through hot dense matter. An out-of-plane trigger particle produces only 26±20% of the away-side pairs that are observed opposite ofan in-plane trigger particle. In contrast, near-side jet fragments are consistent with no suppressionor dependence on trigger orientation with respect to the reaction plane. These observations arequalitatively consistent with a picture of little near-side parton energy loss either due to surface biasor fluctuations and increased away-side parton energy loss due to a long path through the medium.The away-side suppression as a function of reaction-plane angle is shown to be sensitive to both theenergy loss mechanism in and the space-time evolution of heavy-ion collisions. - {location: "https://www.phenix.bnl.gov/phenix/WWW/info/data/ppg116_data.html", description: "web page with data point"}

BNL-RHIC（布鲁克海文国家实验室-相对论重离子对撞机）。本数据集呈现了中心（碰撞中心度0–20%）与半中心（碰撞中心度20–60%）金核-金核（Au+Au）碰撞中，大横向动量中性π介子（neutral pion）触发粒子（p_T=4–7 GeV/c）与带电强子（charged hadron）伴生粒子（p_T=3–7 GeV/c）之间的成对关联，关联结果随触发粒子相对于反应平面（reaction plane）的方位角变化。上述粒子的动量区间高于已观测到喷注形状修正（jet shape modifications）的动量范围，且该成对关联对穿过热密物质（hot dense matter）的部分子（parton）的能量损失具有显著敏感性。面外（out-of-plane）触发粒子产生的背侧成对粒子产额仅为面内（in-plane）触发粒子对应背侧成对粒子产额的26±20%。与之形成鲜明对比的是，近侧（near-side）喷注碎片既未表现出明显的产额抑制，也与触发粒子相对于反应平面的方位角无关联。上述观测结果与以下物理图像定性一致：由于表面偏置（surface bias）或涨落效应，近侧部分子的能量损失可忽略不计；而由于在介质中穿行更长路径，背侧部分子的能量损失显著增强。背侧产额抑制随反应平面角度的变化关系，既对重离子碰撞中的部分子能量损失机制敏感，也对碰撞的时空演化过程具有依赖性。 - {数据源地址: "https://www.phenix.bnl.gov/phenix/WWW/info/data/ppg116_data.html", 数据说明: "包含实验数据点的网页"}