论文标题
重离子碰撞中电磁场引起的定向流动
Directed flow induced by electromagnetic fields in heavy ion collisions
论文作者
论文摘要
预计强烈的电磁场将在中央相对论重离子碰撞中产生，这可以诱导导电颗粒和抗粒子的有向流动的分裂（$ΔV_1$）。这种分裂即使是中性魅力的介子对（$ d^0，\ bar {d}^0 $）也表现出来，因此直接探究了用魅力夸克（Charm Quarks）作为自由程度形成的磨碎相。 在大型$ p_t $的限制中，与QGP的互动较弱，可以获得带电颗粒和反粒子的$ΔV_1（P_T，Y_Z）$的公式，作为$ P_T $和Rapidity $ y_z $的函数，与收力颗粒和集成的效果相关。预计该公式在高$ p_t $下对重夸克和瘦小群有效，在此，由于与QGP和电磁场的相互作用都很小，因此对其运动方程式的修改很小，并且应该具有一般应用。我们还提出了从$ z^0 $衰减及其与$ d $ ersons的相关性的$ΔV_1（p_t，y_z）$的测量值，这将是一个有力的探测，确定实验中测量的大型拆分是否具有电气磁来源。
Strong electromagnetic fields are expected to be generated in off-central relativistic heavy ion collisions, which can induce a splitting of the directed flow of charged particles and anti-particles ($Δv_1$). Such a splitting manifests even for neutral charmed mesons pairs ($D^0,\bar{D}^0$), hence being a direct probe of the formation of deconfined phase with charm quarks as degree of freedom. In the limit of large $p_T$ and weak interaction with the QGP, a formula of $Δv_1(p_T,y_z)$ of charged particles and anti-particles as a function of $p_T$ and rapidity $y_z$ can be obtained, which is found to be related to the spectra of charged particles and the integrated effect of the Lorentz force. This formula is expected to be valid to heavy quarks and leptons at high $p_T$, where the modification to their equations of motion due to the interaction with both QGP and electromagnetic fields is small, and should have a general application. We also proposed a measurement of $Δv_1(p_T,y_z)$ of leptons from $Z^0$ decay and its correlation to that of $D$ mesons, which would be a strong probe determining whether the large splitting measured in experiments has the electromagnetic origin.
