We show that an event-shape engineering based on the mean transverse momentum of charged hadrons, \([p_t]\), provides an optimal handle on the strength of the magnetic field created in central heavy-ion collisions at high energy. This is established through quantitative evaluations of the correlation existing between the event-by-event magnetic field produced by the spectator protons in 5.02 TeV Pb + Pb collisions and the event-by-event \([p_t]\) at a given collision centrality. We argue that the event selection based on \([p_t]\) provides a better handle on the magnetic field than the more traditional selection based on the event ellipticities. Advantages brought by this new method for the experimental search of the chiral magnetic effect are discussed.

我们表明，基于带电强子的平均横向动量\([p_t]\)的事件形状工程提供了对高能中心重离子碰撞中产生的磁场强度的最佳处理。这是通过对 5.02 TeV Pb + Pb 碰撞中观察者质子产生的逐个事件磁场与给定碰撞中心的逐个事件\([p_t]\)之间存在的相关性进行定量评估而建立的. 我们认为基于\([p_t]\)的事件选择比基于事件椭圆度的更传统的选择提供了更好的磁场处理。讨论了这种新方法在手征磁效应实验研究中的优势。