Effect of intense magnetic fields on reduced-magnetohydrodynamics evolution in sNN=200 GeV Au + Au collisions
Effect of intense magnetic fields on reduced-magnetohydrodynamics evolution in sNN=200 GeV Au + Au collisions
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DOI：
10.1103/physrevc.96.054909
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发表时间：
2017-06
影响因子：
3.1
通讯作者：
V. Roy;Shi Pu;L. Rezzolla;D. Rischke
中科院分区：
文献类型：
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作者：
V. Roy;Shi Pu;L. Rezzolla;D. Rischke
我们研究了大磁场对$\sqrt{s_{\rmNN}}$ = 200 GeV Au+Au碰撞中产生的热密核物质的$2+1$维约化磁流体膨胀的影响.为了简单起见，我们考虑磁场指向垂直于反应平面的方向的情况。我们也认为这个领域是外部的，能量密度参数化为二维高斯。高斯分布沿着与束轴正交的方向的宽度随碰撞中心度而变化。对于QGP的零电导率的情况，磁场对固有时间（$\tau$）的依赖性在[Deng 2012]之后被参数化，并且对于有限电导率，在[Tuchin 2013]之后被参数化。我们解决这样的外部磁场的理想流体动力学的运动方程。对于碰撞与非零的影响参数，我们观察到相当大的变化时，在火球的动量偏心率的演变比较的情况下，当磁场衰减在一个导电QGP介质，当没有磁场存在。的椭圆流系数$\pi^{-}$的$v_2$示出增加的存在下，一个外部磁场和增量在$v_2$被发现依赖于演化和磁场的初始大小。
We investigate the effect of large magnetic fields on the $2+1$ dimensional reduced-magnetohydrodynamical expansion of hot and dense nuclear matter produced in $\sqrt{s_{\rm NN}}$ = 200 GeV Au+Au collisions. For the sake of simplicity, we consider the case where the magnetic field points in the direction perpendicular to the reaction plane. We also consider this field to be external, with energy density parametrized as a two-dimensional Gaussian. The width of the Gaussian along the directions orthogonal to the beam axis varies with the centrality of the collision. The dependence of the magnetic field on proper time ($\tau$) for the case of zero electrical conductivity of the QGP is parametrized following [Deng 2012], and for finite electrical conductivity following [Tuchin 2013]. We solve the equations of motion of ideal hydrodynamics for such an external magnetic field. For collisions with non-zero impact parameter we observe considerable changes in the evolution of the momentum eccentricities of the fireball when comparing the case when the magnetic field decays in a conducting QGP medium and when no magnetic field is present. The elliptic-flow coefficient $v_2$ of $\pi^{-}$ is shown to increase in the presence of an external magnetic field and the increment in $v_2$ is found to depend on the evolution and the initial magnitude of the magnetic field.