【作者】 朱励霖； 郑华； 杨纯斌；

【Author】 ZHU Li-lin,ZHENG hua,YANG Chun-bin (Institute of Particle Physics,Hua-Zhong Normal University,Wuhan 430079,China)

【机构】 华中师范大学物理学院粒子物理研究所；

【摘要】 利用SFAR,PHENIX和BRAHMS三个实验组的实验数据,研究不同的碰撞系统、碰撞能量和中心度、快度区下,π介子、质子和反质子横动量谱的标度行为。结果表明质子和反质子的标度行为存在差别,且皆不同于π介子的标度行为,这与粒子的夸克组成有着紧密的联系。用已得到的π介子和质子的标度函数,可以很好地描述质子+质子碰撞中,不同多重数下带电强子横动量分布的标度行为,其标度分布可以表示为π介子和质子标度函数的线形叠加。为了了解质量效应,进一步研究质子和π介子横动能分布的标度行为,发现在低和高动量(横能)区域,横动能的标度性更好。此外,通过分析,发现基于部分子逾渗理论的团碎裂机制可以分别但不能同时描述π介子和质子的标度行为。更多还原

【Abstract】 With the experimental data from STAR,PHENIX and BRAHMS programs on the centrality,rapidity and energy of transverse momentum pT spectrum in Au+Au and d+Au collisions,we show that there exists scaling distributions for pion, proton and antiproton.The difference between the scaling functions for protons and antiprotons is quite small,but they differ a lot from that for pions.Using the obtained scaling functions of pions and protons,we could describe the charged particle pT spectra in p+p collisions as a superposition of those from pion and proton.To estimate the effect of mass,we pursue to investigate the scaling properties of transverse kinetic energy ET distributions of pions and protons,and find the agreement of the scaling ET distribution is better at low and high region.Besides,in the framework of cluster formation and decay mechanism for particle production,the universal transverse energy distributions for pion and proton can be described separately but not simultaneously.更多还原