论文标题
$ψ$（2s）生产和核修饰因子 - 核与爱丽丝核的碰撞
$ψ$(2S) production and nuclear modification factor in nucleus--nucleus collisions with ALICE
论文作者
论文摘要
charmonium的产生对核 - 核碰撞的探测敏感。通过QGP或相边界内的再生生产J/$ψ$的生产已被确定为描述观察到的中心性和$ p _ {\ rm t} $依赖性的重要成分。相对于J/$ψ$的$ψ$（2s）的产量是两个不同再生方案之间的一种歧视者。在RHIC和LHC上，到目前为止，在低横向动量下中央事件中核核酸核碰撞中$ψ$（2s）尚未显着观察，其中再生是主导过程。组合运行的2个数据集的爱丽丝数据集允许在Dimuon衰减通道的正向快速性的这种运动区域中提取明显的$ψ$（2s）信号。在这项贡献中，我们首次出席了$ψ$（2s）-to-j/$ψ$双比和$ψ$（2s）pb-pb碰撞中的核修饰因子$ \ sqrt {s _ {s _ {\ rm nn}}} = 5.02 $ tev，并用新的PP参考，并用新的pp参考。将结果与模型计算进行比较。
Charmonium production is a probe sensitive to deconfinement in nucleus--nucleus collisions. The production of J/$ψ$ via regeneration within the QGP or at the phase boundary has been identified as an important ingredient for the description of the observed centrality and $p_{\rm T}$ dependence at the LHC. $ψ$(2S) production relative to J/$ψ$ is one possible discriminator between the two different regeneration scenarios. At RHIC and at the LHC, there is so far no significant observation of the $ψ$(2S) in nucleus--nucleus collisions in central events at low transverse momentum, where regeneration is the dominating process. The combined Run 2 data set of ALICE allows to extract a significant $ψ$(2S) signal in such a kinematic region at forward rapidity in the dimuon decay channel. In this contribution, we present for the first time results on the $ψ$(2S)-to-J/$ψ$ double ratio and the $ψ$(2S) nuclear modification factor in Pb--Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV, calculated with respect to a new pp reference with improved precision. Results are compared with model calculations.
