In the framework of the Color Glass Condensate, the pseudo-rapidity distributions of charged hadrons in pp and pA collisions at the LHC are studied with the UGD function from the GBW model. With a X2 analysis of the CMS data in pp collisions at √s=0.9, 2.36, 7 TeV, the normalization factor is obtained and the theoretical results are in good agreement with the experimental data. Then, considering the influence of nucleon hard partons transverse distribution on the number of participants in pA collisions by using a Glauber Monte Carlo method, we also give the predictive results for the multiplicity distributions in pPb collisions at √s=4.4 TeV.
By means of the UGD function extracted from an AdS/CFT inspired saturation model, the charm and bottom structure functions are studied in fixed-order perturbation theory. It is shown that the theoretical results are in good agreement with the recent HERA data. Then, this UGD function is also used to investigate net-kaon rapidity distribution in Au＋Au collisions at RHIC energies and the theoretical results fit well to the BRAHMS data. In the end of this paper, we give the predicted results for nuclear charm structure function at very small x where the popular shadowing parameterizations are invalid.
The production of J/ψ mesons in p+p and p+Pb collisions is studied in the framework of color-glass condensate together with a simple color evaporation model.Considering the nuclear effects with the Glauber–Gribov approach,we calculate the cross section and the nuclear modification factor of forward J/ψ production in p+Pb collisions at s^(1/2) 5:02 TeV.Then,the backward J/ψ production in p+Pb collisions at s^(1/2) 8:16 Te V is also analyzed.In our calculation,the phenomenology KLRAd S/CFT model and the rc BK approach,which are valid at a small x,are used to calculate the three-point function.It is shown that the theoretical results fit well with the experimental data from ALICE and LHCb.
Hong-Min WangZhao-Yu HouXiu-Ting WangXian-Jing Sun
利用蒙特卡罗方法计算了平均参与碰撞核子数,通过傅里叶变换从饱和模型中抽取了未积分胶子分布函数解析式,研究了美国相对论重离子对撞机(Relativistic Heavy Ion Collider,RHIC)能量下金-金碰撞中不同碰撞参数区间的重子阻止现象。计算发现:理论结果能够很好地解释BRHAMS合作组实验现象。在此基础上,对正在运行的欧洲大强子对撞机(Large Hadron Collider,LHC)能量下铅-铅碰撞中大快度区域重子阻止现象作出了理论预言。
In the Color Glass Condensate formalism, charged hadron p T spectra in p＋p and p＋Pb collisions are studied by considering an energy-dependent broadening of nucleon density distribution. Then, in the glasma flux tube picture, the n-particle multiplicity distributions at different pseudo-rapidity ranges are investigated. Both the theoretical results show good agreement with the recent experimental data from ALICE and CMS at LHC energies.The predictive results for p T or multiplicity distributions in p＋p and p＋Pb collisions at the Large Hadron Collider are also given in this paper.
