Isospin Effect on the Fragmentation Reaction Induced by Low-energy Antiprotons  

低能反质子引起的原子核碎裂同位旋效应

作　　者：Feng Zhaoqing 

机构地区：[1]不详

出　　处：《IMP & HIRFL Annual Report》2017年第1期3-5,共3页中国科学院近代物理研究所和兰州重离子研究装置年报（英文版）

基　　金：National Natural Science Foundation of China(11722546,11675226);Major State Basic Research Development Program in China(2014CB845405,2015CB856903)。

摘　　要：Since the first evidence of antiprotons was found in 1955 at Berkeley in collisions of protons on copper at the energy of 6.2 GeV,the secondary beams of antiprotons were produced at many laboratories,such as CERN,BNL,KEK,etc.A more localized energy is deposited in the nucleus with an excitation energy of several hundreds of MeV.The hot nucleus proceeds to the explosive decay via multifragmentation process or the sequential particle evaporation.On the other hand,the collisions of the antiproton and secondary particles with surrounding nucleons lead to the pre-equilibrium particle emissions,which are related to the scattering cross sections of each reaction channels,antiproton-nucleon interaction,particle-nucleon potentials,density profile of target nucleus.The unexpected large neutron yields produced by the stopped antiprotons in nuclei were reported in the low energy antiproton ring(LEAR)experiments[1].The phenomena has been puzzling physicists several decades.In this work,the preequilibrium nucleon emissions and the neutron/proton(n/p)spectra in antiproton induced nuclear reactions are investigated within the Lanzhou quantum molecular dynamics(LQMD)transport model.

关 键 词：EQUILIBRIUM EXCITATION FRAGMENTATION 

分 类 号：O57[理学—粒子物理与原子核物理]