The correlation between net baryon number and electric charge, ${\chi }_{11}^{\mathrm{BQ}}$, can serve as a magnetometer of QCD. This is demonstrated by lattice QCD computations using the highly improved staggered quarks with physical pion mass of $M_{\pi }=135\mathrm{MeV}$ on $N_{\tau }=8$ and 12 lattices. We find that ${\chi }_{11}^{\mathrm{BQ}}$ along the transition line starts to increase rapidly with magnetic field strength $eB\gtrsim 2M_{\pi }^2$ and by a factor 2 at $eB\simeq 8M_{\pi }^2$. Furthermore, the ratio of electric charge chemical potential to baryon chemical potential, ${\mu }_{\mathrm{Q}}/{\mu }_{\mathrm{B}}$, shows significant dependence on the magnetic field strength and varies from the ratio of electric charge to baryon number in the colliding nuclei in heavy ion collisions. These results can provide baselines for effective theory and model studies, and both ${\chi }_{11}^{\mathrm{BQ}}$ and ${\mu }_{\mathrm{Q}}/{\mu }_{\mathrm{B}}$ could be useful probes for the detection of magnetic fields in relativistic heavy ion collision experiments as compared with corresponding results from the hadron resonance gas model.

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重子电荷相关性作为 QCD 磁力计

净重子数与电荷之间的相关性，${\chi }_{11}^{\mathrm{贝奇}}$，可以作为QCD磁力计。这通过晶格 QCD 计算得到了证明，该计算使用了高度改进的交错夸克，其物理π介子质量为${\mathrm{中号}}_{\pi }=135\mathrm{兆伏}$在${氮}_{\tau }=8$和12个格子。我们发现${\chi }_{11}^{\mathrm{贝奇}}$沿着过渡线开始随着磁场强度迅速增加$e乙\gtrsim 2{\mathrm{中号}}_{\pi }^2$并乘以 2 倍$e乙\simeq 8{\mathrm{中号}}_{\pi }^2$。此外，电荷化学势与重子化学势之比，${\mu }_{\mathrm{问}}/{\mu }_{\mathrm{乙}}$，显示出对磁场强度的显着依赖性，并且随重离子碰撞中碰撞核中电荷与重子数的比率而变化。这些结果可以为有效的理论和模型研究提供基线，并且${\chi }_{11}^{\mathrm{贝奇}}$和${\mu }_{\mathrm{问}}/{\mu }_{\mathrm{乙}}$与强子共振气体模型的相应结果相比，可以成为相对论重离子碰撞实验中检测磁场的有用探针。