论文标题
$ p $ -pb碰撞的多数依赖性饱和动量在5.02 TEV
Multiplicity-dependent saturation momentum in $p$-Pb collisions at 5.02 TeV
论文作者
论文摘要
LHC能量在质子质子和质子铅核碰撞中观察到的半含横向动量光谱在LHC能量下使用缩放变量使用多重性依赖性饱和动量，遵守几何缩放。从实验数据中提取的饱和动量与最终状态下强子多重性的1/6功率成正比。另一方面，系统的横向大小与多重性的1/3功率成正比，并且系统的饱和动量和系统的横向大小与最终状态下的强子多重性密切相关。由于饱和动量与Hadron的平均横向动量成正比，因此预测平均横向动量也与多样性的1/6功率成正比，这与LHC能量的实验结果一致。我们发现，由依赖多样性的饱和动量计算得出的核修饰因子$ r _ {\ rm ppb} $在$ p _ {\ rm t} \ sillesim $ 1GEV/$ c $下降，我们的模型可以部分地解释$ r _ {\ rm ppb} $由核造成的核态，以部分地解释$ r _ {\ rm ppb}。另一方面，在$ 2 \ Lessim p _ {\ rm t} \ Lessim $ 6 Gev/$ c $的情况下，在实验上观察到的Cronin增强功能未重现。但是，可以通过引入$ p _ {\ rm t} $依赖性作为4 $ \ sim $ 5 \％校正对多重性依赖性饱和势头的校正来很好地复制实验结果，包括克罗宁效应。
Semi-inclusive transverse momentum spectra observed in proton-proton and proton-lead nuclear collisions at LHC energies obey a geometric scaling with a scaling variable using multiplicity-dependent saturation momentum. The saturation momentum extracted from the experimental data is proportional to the 1/6 power of the hadron multiplicity in the final state. On the other hand, the system's transverse size is proportional to the 1/3 power of the multiplicity, and the saturation momentum and the transverse size of the system are strongly correlated with the hadron multiplicity in the final state. Since the saturation momentum is proportional to the average transverse momentum of hadrons, one predicts average transverse momentum is also proportional to the 1/6 power of the multiplicity, which is consistent with experimental results at the LHC energy. We found that a nuclear modification factor $R_{\rm pPb}$ calculated by the multiplicity-dependent saturation momentum decreases at $p_{\rm T} \lesssim$ 1GeV/$c$ and that our model can partially explain the $R_{\rm pPb}$'s behavior thought to be caused by nuclear shadowing. On the other hand, Cronin enhancement experimentally observed at $2 \lesssim p_{\rm T} \lesssim $ 6 GeV/$c$ is not reproduced. However, the experimental result, including the Cronin effect, can be reproduced well by introducing $p_{\rm T}$ dependence as a 4$\sim$5\% correction to the multiplicity-dependent saturation momentum.We also discuss a relation between the geometric scaling in the semi-inclusive distributions and the string percolation model.
