论文标题
j/$ψ$和$ψ$（2s）的中心性依赖性在$ \ sqrt {s _ {\ rm nn}} = $ 8.16 TEV
Centrality dependence of J/$ψ$ and $ψ$(2S) production and nuclear modification in p-Pb collisions at $\sqrt{s_{\rm NN}} =$ 8.16 TeV
论文作者
论文摘要
j/$ψ$和$ψ$（2s）炭状态的包容性生产作为P-PB碰撞中心性的函数，每核对$ \ sqrt {s _ {\ rm nn}} = 8.16 $ tev the lhc in nucleon collisision collisision collisions in nucleon Pair $ \ sqrt $ \ sqrt {s _ {\ rm nn}} = 8.16 $ tev。该测量是在Dimuon衰减通道中，具有爱丽丝设备的质量速度间隔$ -4.46 <y _ _ {\ rm cms} <-2.96 $（pb-toendion）和$ 2.03 <y _ _ _ _ {\ rm cms} t} $）。 J/$ψ$和$ψ$（2s）生产横截面的评估是碰撞中心性的函数，该函数通过位于PB-theendion的零度热量表中的能量估计。 $ p _ {\ rm t} $ - 微分j/$ψ$生产横截面的几个中心级别的向后和向前速度测量，以及相应的平均$ \ langle p _ {\ rm t} \ rangle $和$ \ langle p^{2}} _ {2} _ {\ rm rm t}。使用核修饰因子研究了影响两个慈善状态产生的核效应。从p进程的方向上，观察到了两个炭态生产的抑制，这似乎从外围碰撞到中央碰撞增加。然而，在PB前进的方向上，两种状态的中心性依赖性不同：J/$ψ$的核修饰因子从外围碰撞的低于统一到中心碰撞中的统一，而对于$ψ$（2s），它在低于或一致的中心居住的$ψ$（2s）中，没有明显的中心依赖性。将结果与$ \ sqrt {s _ {\ rm nn}}} = 5.02 $ TEV的P-PB碰撞中的测量结果进行了比较，并且观察到对碰撞能量的显着依赖。最后，将结果与实施各种核物质效应的理论模型进行了比较。
The inclusive production of the J/$ψ$ and $ψ$(2S) charmonium states is studied as a function of centrality in p-Pb collisions at a centre-of-mass energy per nucleon pair $\sqrt{s_{\rm NN}} = 8.16$ TeV at the LHC. The measurement is performed in the dimuon decay channel with the ALICE apparatus in the centre-of-mass rapidity intervals $-4.46 < y_{\rm cms} < -2.96$ (Pb-going direction) and $2.03 < y_{\rm cms} < 3.53$ (p-going direction), down to zero transverse momentum ($p_{\rm T}$). The J/$ψ$ and $ψ$(2S) production cross sections are evaluated as a function of the collision centrality, estimated through the energy deposited in the zero degree calorimeter located in the Pb-going direction. The $p_{\rm T}$-differential J/$ψ$ production cross section is measured at backward and forward rapidity for several centrality classes, together with the corresponding average $\langle p_{\rm T} \rangle$ and $\langle p^{2}_{\rm T} \rangle$ values. The nuclear effects affecting the production of both charmonium states are studied using the nuclear modification factor. In the p-going direction, a suppression of the production of both charmonium states is observed, which seems to increase from peripheral to central collisions. In the Pb-going direction, however, the centrality dependence is different for the two states: the nuclear modification factor of the J/$ψ$ increases from below unity in peripheral collisions to above unity in central collisions, while for the $ψ$(2S) it stays below or consistent with unity for all centralities with no significant centrality dependence. The results are compared with measurements in p-Pb collisions at $\sqrt{s_{\rm NN}} = 5.02$ TeV and no significant dependence on the energy of the collision is observed. Finally, the results are compared with theoretical models implementing various nuclear matter effects.
