Pomeron Loop Effects In Deep Inelastic Scattering And The High Twist Processes In Proton-nuclear Collision

Perturbation QCD(pQCD)predicted at a sufficiently high energy,because of the gluon radiation,a parton of the nucleus will reaches saturation,it will form a dense system,called color Glass Condensate(CGC),usually described by CGC theory.In this theoretical framework,the pomeron loop effects in the latest HERA data are studied by the diffusive scaling which is resulting from the pomeron loop equations and also a main hallmark of the pomeron loop effects.For this,on the one hand,by analyzing the latest HERA data with quality factor method,we obtain the saturation exponent,?=0.208.On the other hand,which turns out reasonable and is in agreement with the theoretical expectations.To intuitively show the diffusive scaling,we plot the cross section versus scaling variable,and observe that the experimental data almost lie on a same curve in both inclusive and diffractive data,respectively.These outcomes indirectly imply a possible involvement of the pomeron loop effects in the latest HERA data.In addition,the lattice QCD at finite temperature predicted that quark gluon plasma(QGP)can be formed in the high temperature and density.In order to study its physical feature,jet quenching is usually used as a hard probe to explore the production of QGP.In a thermonuclear medium,inducing gluon radiation will lead to energy loss when high-speed parton pass through the nuclear medium;For cold nuclear medium,there is also a loss of parton energy caused by the multiple scattering.So far,the energy loss problem of electron-nuclear(eA)deep inelastic scattering and the proton-nuclear(pA)collision in the Drell-Yan process has been studied in the literature.The results show that the energy loss caused by multiple scattering will cause the modification of the parton fragmentation function in the eA collision but in the pA collision,it will cause the modification of parton distribution function,which is experimentally reflected as the corresponding nuclear modification factor depression.In the previous study,the Drell-Yan process of proton-nuclear(pA)collision observed that the modification of the parton distribution function caused by the incoming parton energy loss which caused by the gluon-quark double scattering.However,this process ignored the quark-quark double scattering to the modification of the parton distribution function.In constrast,after only considering the quark-quark double scattering of the Drell-Yan process,we find that it not only can improve the modified parton distribution function but also can have a flavor dependence effect for quark-quark double-scattering nuclear modification factor which means that the modification factor of the collision cross section are not equal for proton-nuclear collision and antiproton-nuclear.The two nuclear modification factor depend on the quark and antiquark distribution functions in the nuclear,respectively,and so there is a flavor dependence effect of nuclear modification factor.