标题： 0.6到2.0 AGeV入射能量下重离子碰撞中K+和K-介子的产生 显示英文标题

标题： Production of K+ and of K- Mesons in Heavy-Ion Collisions from 0.6 to 2.0 AGeV Incident Energy

摘要： 本文总结了在入射能量从0.6 AGeV到2.0 AGeV的包含C+C、Ni+Ni和Au+Au碰撞中，使用GSI的K介子光谱仪KaoS测量的K+和K-介子的产率和发射模式。 对于1.5和1.93 AGeV的Ni+Ni碰撞以及1.5 AGeV的Au+Au碰撞，详细展示了粒子多重性、能量分布的逆斜率参数以及作为碰撞中心度函数的角发射模式各向异性结果。 当将输运模型计算与测量的K+产率进行比较时，仅在软核状态方程（压缩模量KN ~ 200 MeV）的情况下获得一致结果。 在约1到2 AGeV能量下，K-介子的产生主要由奇异数交换反应K- N <-> pi Y（Y = Lambda, Sigma）主导，这导致K-和K+产率之间的耦合。 然而，这两种粒子种类在它们的发射模式上表现出明显的差异，表明K+和K-介子有不同的冻结条件。 显示英文摘要

摘要： This paper summarizes the yields and the emission patterns of K+ and of K- mesons measured in inclusive C+C, Ni+Ni and Au+Au collisions at incident energies from 0.6 AGeV to 2.0 AGeV using the Kaon Spectrometer KaoS at GSI. For Ni+Ni collisions at 1.5 and at 1.93 AGeV as well as for Au+Au at 1.5 AGeV detailed results of the multiplicities, of the inverse slope parameters of the energy distributions and of the anisotropies in the angular emission patterns as a function of the collision centrality are presented. When comparing transport-model calculations to the measured K+ production yields an agreement is only obtained for a soft nuclear equation of state (compression modulus KN ~ 200 MeV). The production of K- mesons at energies around 1 to 2 AGeV is dominated by the strangeness-exchange reaction K- N <-> pi Y (Y = Lambda, Sigma) which leads to a coupling between the K- and the K+ yields. However, both particle species show distinct differences in their emission patterns suggesting different freeze-out conditions for K+ and for K- mesons.