色玻璃凝聚近似下极端相对论重离子碰撞中的双轻子和光子产生（英文）  

Dileptons and Photons Production in Ultrarelativistic Heavy Ion Collisions from the Color Glass Condensate

作　　者：余功明[1] 杨海涛[2] 李云德[1] 

机构地区：[1]云南大学物理系,昆明650091 [2]昭通学院物理与电子信息工程学院,云南昭通657000

出　　处：《原子核物理评论》2016年第1期25-29,共5页Nuclear Physics Review

基　　金：National Natural Science Foundation of China(11465021,11065010)~~

摘　　要：在色玻璃凝聚胶子饱和框架下,研究了相对论重离子碰撞中的双轻子和光子产生。在胶子饱和区域,在微扰近似(kT-因子化近似)下低转移动量双轻子和光子的主要产生机制是胶子-胶子相互作用。在RHIC和LHC能量区域的相对论重离子碰撞中,饱和动量的值远远大于量子色动力学禁闭标度ΛQCD,这使得αs?1。此时,当转移动量小于饱和动量Qs时质子和原子核的胶子密度值就会很高,双轻子和光子的不变产生横截面会由于饱和效应而得到增强。数值结果给出在RHIC和LHC能量区域的pp,p A和AA碰撞中,来源于色玻璃凝聚的低转移动量双轻子和光子产生贡献是显著的。We investigate inclusive dileptons and photons production in relativistic heavy ion collisions based on the idea of gluon saturation in the color glass condensate （CGC） framework. In the gluon saturation region, the dominant mechanism for low-pT dileptons and photons production in the pertur- bative approach （the κτ-factorization approach） is gluon-gluon interaction. At Relativistic Heavy Ion Collider （RHIC） and Large Hadron Collider （LHC） energies, the value of saturation momentum becomes larger than the Quantum Chromodynamics （QCD） confinement scale AQCD for relativistic heavy ion col- lisions, which implies that αs ≤ 1. In this state, the gluon density for proton and nucleus with transverse momentum less than the saturation momentum Qs will reach a high value, and the invariant cross-section for dileptons and direct photons is further enhanced by saturation effects. The numerical results indicate that the production of low-pT dileptons and photons from the color glass condensate becomes prominent in pp, pA, and AA collisions at RHIC and LHC energies.

关 键 词：双轻子 光子 色玻璃凝聚 重离子碰撞 

分 类 号：O571.6[理学—粒子物理与原子核物理]