重离子碰撞中K介子和π介子产生的统一动力学模拟

用RVUU模型统一地研究了重离子碰撞中产生的K介子和π介子的动力学过程.考虑了K产生和输运过程的介质效应,同时,计入了π在核物质中的传播.用它模拟了每核子1GeV入射能量的重离子碰撞中π产生和阈下K产生过程.讨论了核介质效应对π末态性质的影响,以及对K末态性质的联带影响.计算结果表明,吸引的π光学势,影响了末态π动量分布,使横动量分布中具有小动量的π产额增大,同时明显增大了K的产额,改变了K的动量分布.这说明要合理地评价重离子碰撞的探测信息,需要统一地研究K和π的这些末态动力学作用.

Unified Dynamical Simulation of Kaon and PionProduction in Heavy Ion Collisions

The RVUU model is used to study dynamical processes of the kaon and pion produced in heavy ion collisions.We include the nuclear medium effect on kaon and pion in the model, and simulate pion production and kaon subthreshold production process in heavy ion collisions at 1 GeV/nucleon.The calculated results show that the attractive pion optical potential changes the final pion momentum spectrum,increasing transverse momentum spectrum at the low momentum region.At the same time it also apparently enhances kaon abundance and modifies kaon momentum distribution.It illustrates that both kaon and pion final state dynamic processes should be considered in order to make a reasonable comment on the signals in heavy ion collisions.