膨胀的热夸克胶子物质的中等质量双轻子的增强

Enhancement of intermediate mass dileptons from expanding hot quark-gluon matter

基于一个描述夸克 胶子火柱演化的相对论流体力学模型 ,研究了夸克相、强子相互作用以及非热过程 (Drell Yan对、粲强子衰变 )的中等质量双轻子的产生 .发现由于相边对夸克 胶子物质演化的影响和RHIC能量核碰撞产生的夸克 胶子物质具有高的初始温度 ,夸克相对双轻子的贡献显著增强 ,比那些来自强子相互作用的贡献重要 ,甚至能与来自非热的贡献比较 .表明中等质量双轻子的增强是一个在核碰撞中产生了夸克 胶子物质的可能信号 .

A study of the production of intermediate mass dileptons from the quark phase and hadronic interactions as well as nonthermal contributions (Drell-Yan pairs,charmed hadronic decays)in the initial stage has been carried out based on a relativistic hydrodynamic model describing the evolution of a quark-gluon matter fire-cylinder.We find that due to the influence of the phase boundary on the evolution of the quark-gluon matter system and the high initial temperature of the quark-gluon matter produced at RHIC energies,the contribution of the quark phase to dileptons is obviously enhanced and is more important than those from hadronc interactions and even is comparable with those from nonthermal contributions.It is shown that the enhancement of intermediate mass dileptons is a possible signature for the quark-gluon matter formation in heavy ion collisions at RHIC energies.