With the PICR hydrodynamic model, we study the polarization splitting between \(\varLambda \) and \(\bar{\varLambda }\) at RHIC BES energy range, based on the meson field mechanism. Our results fit to the experimental data fairly well. Besides, two unexpected effect emerges: (1) the baryon density gradient has non-trivial and negative contribution to the polarization splitting; (2) for 7.7 GeV Au+Au collisions within the centrality range of 20–50%, the polarization splitting surprisingly increases with the centrality decreases. The second effect might help to explain the significant signal of polarization splitting measured in STAR’s Au+Au 7.7 Gev collisions.

利用PICR水动力模型，我们基于介子场机制研究了RHIC BES能量范围内\（\ varLambda \）和\（\ bar {\ varLambda} \）之间的极化分裂。我们的结果非常符合实验数据。此外，还出现了两个意想不到的影响：（1）重子密度梯度对偏振分裂具有不平凡的负面影响；（2）在中心度20–50％范围内发生7.7 GeV Au + Au碰撞时，极化分裂随着中心度的降低而令人惊讶地增加。第二个效果可能有助于解释在STAR的Au + Au 7.7 Gev碰撞中测得的偏振分裂的重要信号。