Multiplicities of forward-backward particles in ^(16)O-emulsion interactions at 4.5 AGeV/c  

作　　者：李惠玲 张东海 李俊生 

机构地区：[1]Institute of Modern Physics,Shanxi Normal University

出　　处：《Chinese Physics C》2009年第7期521-527,共7页中国物理C（英文版）

基　　金：Supported by National Natural Science Foundation of China (10475054, 10675077);Natural Science Foundation of Shanxi Province China (200811005);Shanxi Provincial Foundation for Returned Scholars of China (20031046)

摘　　要：An exclusive study of the characteristics of interactions accompanied by backward emission（θlab 90°） of shower and grey particles in collisions of a 4.5 AGeV/c ^16O beam with emulsion nuclei is carried out. The experimental multiplicity distributions of different particles emitted in the forward（θlab 〈 90°） and backward hemispheres due to the interactions with the two emulsion components（CNO,AgBr） are presented and analyzed. The correlations between the different emitted particles are also investigated. The results indicate that there are signatures for a collective mechanism,which plays a role in the production of particles in the backward hemisphere. Hence,the backward multiplicity distribution of the emitted shower and grey particles at 4.5 AGeV/c incident momentum can be represented by a decay exponential law formula independent of the projectile size. The exponent of the power was found to increase with decreasing target size. The experimental data favor the idea that the backward particles were emitted due to the decay of the system in the latter stages of the reactions.An exclusive study of the characteristics of interactions accompanied by backward emission（θlab 90°） of shower and grey particles in collisions of a 4.5 AGeV/c ^16O beam with emulsion nuclei is carried out. The experimental multiplicity distributions of different particles emitted in the forward（θlab 〈 90°） and backward hemispheres due to the interactions with the two emulsion components（CNO,AgBr） are presented and analyzed. The correlations between the different emitted particles are also investigated. The results indicate that there are signatures for a collective mechanism,which plays a role in the production of particles in the backward hemisphere. Hence,the backward multiplicity distribution of the emitted shower and grey particles at 4.5 AGeV/c incident momentum can be represented by a decay exponential law formula independent of the projectile size. The exponent of the power was found to increase with decreasing target size. The experimental data favor the idea that the backward particles were emitted due to the decay of the system in the latter stages of the reactions.

关 键 词：relativistic heavy-ion collisions multifragment emission and correlations nuclear emulsion 

分 类 号：O571.4[理学—粒子物理与原子核物理] Q592.6[理学—物理]