重离子碰撞中K+介子的横动能谱

Transverse Kinematical Energy Spectra of K+ Mesons in Heavy Ion Collisions

本文采用基于协变的K动力学的量子分子动力学模型,研究了1.93 AGeV入射能量的58Ni + 58Ni碰撞中产生的K+介子的横动能谱,并讨论了K+介子在介质中的位势对其横动能谱的影响。理论计算显示,只有计入K+介子在核介质中的位势的效应,才能合理地描写KaoS的实验数据。这表明,我们能从K+介子横动能谱的分析中提取出在核介质中K+介子位势的信息。同时,我们发现,K+介子的横动能谱也是一个探测核物态方程的敏感的观测量。

We use the quantum molecular dynamics model based on the covariant kaon dynamics to investi- gate the transverse kinematical energy spectra of K+ mesons from 58Ni + 58Ni collisions at 1.93 AGeV, and discuss the influence of the K+ in-medium potential on its transverse kinematical energy spectrum. We observe that the KaoS data can only be reasonably described by calculated results with a repulsive K+N potential. This indicates that one can extract the information on the K+ in-medium potential in a nuclear medium from the analysis of the transverse kinematical energy spectra of K+ mesons. We find that the transverse kinematical energy spectrum of K+ mesons is also a sensitive observable to probe the nuclear equation of state.