LHC上J/ψ粒子的产生对束缚核子胶子分布函数的约束

The production of J/ψ on LHC and the nuclear gluon density

根据色蒸发模型,应用EKS98及HKM04的程序,计算了在LHC上p-Pb碰撞过程中J/ψ粒子的微分产值比.在LHC的能量范围内,此比值近似于胶子的核效应因子.本文数据与未来LHC上p-Pb碰撞的实验数据对比,可以修正高能时此二种程序对束缚核子胶子分布函数的描述,对束缚核内胶子密度提供高能时的约束.

Using color evaporation model we calculated the ratio of J/ψ production cross section with different nuclear effect factors： EKS98 and HKM.Because under the collision energy of LHC J/ψ is produced at small longitudinal momentum Fraction（xF1）,the gluon fusion channel dominates over the q-q annihilation process.As a result,this radio is nearly equals to the gluon nuclear effect factor.Compared it with the future LHC experiment data we can get further constraints on the nuclear gluon PDFs under high collision energy,which would be useful for the studies of perturbative evolution on hadrons production.