We study the space-averaged electromagnetic (EM) fields weighted by the energy density in the central regions of heavy-ion collisions. These average quantities can serve as a barometer for the magnetic-field induced effects such as the magnetic effect, the chiral separation effect and the chiral magnetic wave. Comparing with the magnetic fields at the geometric center of the collision, the space-averaged fields weighted by the energy density are smaller in the early stage but damp slower in the later stage. The space average of squared fields as well as the EM anomaly $\mathbf{E}·\mathbf{B}$ weighted by the energy density are also calculated. We give parametrized analytical formulas for these average quantities as functions of time by fitting numerical results for collisions in the collision energy range $7.7–200$ GeV with different impact parameters.

中文翻译：

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重离子碰撞中空间平均电磁场和以能量密度加权的电磁异常

我们研究了由重离子碰撞中心区域的能量密度加权的空间平均电磁 (EM) 场。这些平均量可以作为磁场感应效应的晴雨表，例如磁效应、手性分离效应和手性磁波。与碰撞几何中心的磁场相比，能量密度加权的空间平均场在前期较小，后期衰减较慢。平方场的空间平均以及电磁异常$\mathbf{乙}·\mathbf{乙}$还计算了能量密度的权重。我们通过拟合碰撞能量范围内碰撞的数值结果，给出这些平均量的参数化分析公式作为时间的函数$7.7——200$ GeV 具有不同的冲击参数。