高能强子-强子碰撞中硬软过程的比较分析  

Comparison of the Hard and Soft Processes in High Energy Hadron Hadron Collisions

作　　者：柳峰 刘峰[1] 

机构地区：[1]华中师范大学粒子物理研究所

出　　处：《高能物理与核物理》1997年第4期330-339,共10页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金;国家教委优秀年轻教师基金;湖北省自然科学基金;武汉市青年科技晨光计划资助

摘　　要：根据ＱＣＤ中“圆锥定义”来确定喷注，对高能强子－强子碰撞中的硬、软过程作细致的分析．用Ｐｙｔｈｉａ产生蒙特卡罗模拟样本，得到的喷注赝快度分布在中心区有平台，喷注内部的粒子密度和横能密度，随离喷注轴的距离指数地下降，比较发现对整个事件样本，单事件平均横动量或最大横动量与多重数是正关联的，而对喷注事件它们是负关联的．引入两个物理量来描述喷注事件的硬、软程度．发现它们与单事件平均横动量是正关联的，而与多重数是负关联的．Using the “cone algorithm” in QCD to identify jet,the hard and soft processes in high energy hadronci collisions are analysed in detail.A Monte Carlo simulation event sample is produced by PYTHIA.The resultant pseudorapidity distribution of jets has a plateau in the central region.The particle and transverse energy density in jets decreases exponentially with the increase of the distance from particles to jet axis.Through comparisons,we find the event average transverse momentum or maximum transverse momentum is positively correlated with multiplicity for the whole event sample,and negatively correlated with multiplicity for jet event subsample.Two ratio variables well describe the hardness of jet events,and they are positively correlated with the event average transverse momentum and negatively correlated with multiplicity,which confirms the event average transverse momentum is a better characteristic quantity to describe the hardness of jet events than multiplicity.

关 键 词：高能 强子-强子碰撞 喷注 圆锥判定法 

分 类 号：O572.2[理学—粒子物理与原子核物理]