论文标题
$ \ sqrt {s_ \ mathrm {nn}} = $ 5.02 TEV
Nuclear modification of $Υ$ states in pPb collisions at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV
论文作者
论文摘要
生产交叉部分的生产交叉部分，使用$ \ sqrt {s_ \ Mathrm {s_ \ Mathrm {nnn}} te Tev. $υ$（2s）和$υ$（3s）状态腐烂成$μ^+μ^ - proton-Lead（PPB）colionisions colvisions comcrients coms in Comm in Comm in Comm in Comm in Comm in Comm in Comm in compients comm cms coltisions in $ \ sqrt {s_ \ mathrm {s_ \ mathrm {nnn}}}}}}} = $ 5.0。比较与以相同的碰撞能量测量并通过Pb核质量数缩放的相应横截面进行了比较。发现$υ$（1s）的核修饰因子为$ r_ \ m m iathrm {ppb}（υ（1s））$ = 0.806 $ \ pm $ 0.024（stat）$ \ pm $ 0.059（syst）。激发状态的类似结果表示顺序抑制模式，因此$ r_ \ mathrm {ppb}（υ（1S））$ $ $ \ gt $ \ gt $ $ $ $ $ r_ \ mathrm {ppb}（υ（2S）$ $ $ $ $ \ gt $ $ $ $ $ $ $ r_ \ mathrm {ppb} {ppb} $。 PPB中的抑制不及PBPB的碰撞，而与横向动量$ p_ \ mathrm {t}^购$和质量中心快速性$ y_ \ y_ \ mathrm {cm {cm} $ \ vert y_ \ mathrm {cm}^υ\ vert $ $ \ lt $ 1.93。与仅假设初始状态修改的模型合并了PPB碰撞中底部底虫的模型与数据吻合更好。
Production cross sections of $Υ$(1S), $Υ$(2S), and $Υ$(3S) states decaying into $μ^+μ^-$ in proton-lead (pPb) collisions are reported using data collected by the CMS experiment at $\sqrt{s_\mathrm{NN}} =$ 5.02 TeV. A comparison is made with corresponding cross sections obtained with pp data measured at the same collision energy and scaled by the Pb nucleus mass number. The nuclear modification factor for $Υ$(1S) is found to be $R_\mathrm{pPb}(Υ(1S))$ = 0.806 $\pm$ 0.024 (stat) $\pm$ 0.059 (syst). Similar results for the excited states indicate a sequential suppression pattern, such that $R_\mathrm{pPb}(Υ(1S))$ $\gt$ $R_\mathrm{pPb}(Υ(2S))$ $\gt$ $R_\mathrm{pPb}(Υ(3S))$. The suppression is much less pronounced in pPb than in PbPb collisions, and independent of transverse momentum $p_\mathrm{T}^Υ$ and center-of-mass rapidity $y_\mathrm{CM}^Υ$ of the individual $Υ$ state in the studied range $p_\mathrm{T}^Υ$ $\lt$ 30 GeV$/c$ and $\vert y_\mathrm{CM}^Υ\vert$ $\lt$ 1.93. Models that incorporate sequential suppression of bottomonia in pPb collisions are in better agreement with the data than those which only assume initial-state modifications.
