高能核-核碰撞中喷注淬火效应增强与直接光子各项异性的研究  

Enhanced jet-quenching effect and azimuthal anisotropy of direct photons in high energy nuclear-nuclear collisions

作　　者：曹丽萍[1] 吴怡芬[1] 杜淅霞[1] 汪仲文[2] 

机构地区：[1]新疆喀什师范学院物理系,喀什844006 [2]新疆喀什师范学院数学系,喀什844006

出　　处：《华中师范大学学报（自然科学版）》2010年第3期407-411,共5页Journal of Central China Normal University：Natural Sciences

基　　金：国家自然科学基金资助项目(10747003)

摘　　要：通过计算给出了在LHC能区非对心核一核碰撞中由椭圆流v_2表示的高横动量直接光子的方位角不对称性.该高横动量光子是由喷注与热密介质相互作用而辐射出来的.光子椭圆流与强子椭圆流v_2相差π/2的相位,是直接光子椭圆流中负值的来源.同时,计算表明LHC能区直接光子v_2随粒子横动量p_T的变化趋势与RHIC上的实验结果一致,但LHC能区较RHIC能区直接光子流v_2值更小,且v_2值由负到正对应的转换p_T值更高.这表明在LHC能区喷注淬火效应更为明显,表面发射的直接光子对光子椭圆流的贡献份额增强.The azimuthal anisotropy of high PT direct photons is investigated by using the coefficient of elliptic flow v2 in non-central nuclear-nuclear collision at LHC energies. These photons come from the radiation induced by the interaction between jet and hot/ dense medium. We find that there is π/2 difference between direct photons and hadrons for the azimuthal elliptic flow v2. Such photons are the main source of the negative part of v2 for direct photons. The dependence of the direct photon v2 on the transverse momentum PT at LHC energy is found to be consistent with the experimental results at RHIC energy. Furthermore, we find that the value of the direct photon v2 at LHC energy is smaller than that at RHIC energy. The value of the transverse momentum which the direct photon v2 changes from negative value to positive at LHC is higher than that at RHIC. We conclude it is because the enhanced jet-quenching effect and enhanced contribution for the elliptic flow v2 of the direct photons emitted from surface at LHC energy.

关 键 词：直接光子 高能核-核碰撞 喷注淬火 椭圆流 

分 类 号：O571.21[理学—粒子物理与原子核物理]