体积效应对k介子HBT关联函数的影响

The effect of finite size of hardons on kaon of correlation function

对于不同尺寸的源,体积效应会对π介子产生影响.对于较小的源,体积效应会导致归一化参数明显减小,HBT半径减小,归一化参数也会减小,体积效应对于HBT半径和混沌参量的影响是非常小的.同时,体积效应也会对k介子关联函数产生影响.分别讨论了在小的粒子对横动量区域(0.15<K_(T)<0.25)以及大的粒子对横动量区域(0.35<K_(T)<0.45),体积效应对关联函数的影响.结果发现,当没有考虑体积效应时,随着动量q的增加,关联函数C(q)逐渐减小,趋近于1;考虑了体积效应的影响,随着动量q的增加,关联函数C(q)逐渐减小,趋近于1,且小于1;同时讨论了随着截断时间的增加,这种趋势变得更加明显,截断时间越大,关联函数小于1就出现的越早,这与实验观测结果相吻合.

The influence of finite size of hardons on pion is related to the size of source.The effect of the composite nature on HBT radius and chaos parameters is very small,the normalized parameter was significantly reduced by the composite nature in small source,and decreases as HBT radii decreases.At the same time,finite size of hardons also effect the correlation function of kaon.We discuss the effect of finite size of hardons on correlation function respectively in small region of transverse momentum(0.15<K_(T)<0.25)and large region of transverse momentum(0.35<K_(T)<0.45).The results show that when the finite size of hardons is not considered,correlation function C(q)decreases gradually with the increase of monentum q,and it will approaches to 1finally.When the finite size of hardons is considered,correlation function C(q)decreases gradually with the increase of momentum q,it will tend to 1 and less than 1 finally.It is also discussed that this trend becomes more obvious with the increase of cut-off time.The correlation function is less than 1 appear earlier for larger cut-off time,which is consistent with the experimental observation results.