论文标题
重离子碰撞中的$ d^*/d $比率
The $D^*/D$ ratio in heavy ion collisions
论文作者
论文摘要
在这项工作中，我们研究了$ d^*$和$ d $多重性，以及它们在重离子碰撞的强子气相中的变化。在有效的拉格朗日形式主义的帮助下，我们计算了hadronic培养基中$ d^*$和$ d $介子的生产和吸收横截面。我们计算丰度的时间演变和比率$ d^* /d $。它们的时间大约是恒定的。同样，假设Bjorken型冷却，并使用冷冻温度和中央多样性密度之间的经验关系，我们估计$ d^* /d $作为$ dn /dη（η= 0）$的函数，该函数代表系统大小。我们发现，虽然$ d^*$的数量和$ d $的数量随着系统尺寸而显着增长，但它们的比率大约是恒定的。该预测可以与将来的实验数据进行比较。我们的结果表明，强子气体中的魅力梅森相互作用不会改变其多重性，因此这些介体接近化学平衡。
In this work we study the $D^*$ and $D$ multiplicities and how they change during the hadron gas phase of heavy ion collisions. With the help of an effective Lagrangian formalism, we calculate the production and absorption cross sections of the $D^*$ and $D$ mesons in a hadronic medium. We compute the time evolution of the abundances and the ratio $D^* /D$. They are approximately constant in time. Also, assuming a Bjorken type cooling and using an empirical relation between the freeze-out temperature and the central multiplicity density, we estimate $D^* /D$ as a function of $ dN /d η(η=0)$, which represents the system size. We find that, while the number of $D^*$'s and $D$'s grows significantly with the system size, their ratio remains approximately constant. This prediction can be compared with future experimental data. Our results suggest that the charm meson interactions in the hadron gas do not change their multiplicities and consequently these mesons are close to chemical equilibrium.
