We present a measurement of the first-order azimuthal anisotropy, $v_1$, of deuterons from Au+Au collisions at $\ems$ = 7.7, 11.5, 14.5, 19.6, 27, and 39 GeV recorded with the STAR experiment at the Relativistic Heavy Ion Collider (RHIC). The energy dependence of the $\vone$ slope, $\dvdy|_{y=0}$, for deuterons, where $y$ is the rapidity, is extracted for semi-central collisions (10-40% centrality) and compared to that of protons. While the $\vone$ slopes of protons are generally negative for $\ems >$ 10 GeV, those for deuterons are consistent with zero, a strong enhancement of the $\vone$ slope of deuterons is seen at the lowest collision energy (the largest baryon density) at $\ems =$ 7.7 GeV. In addition, we report the transverse momentum dependence of $v_1$ for protons and deuterons. The experimental results are compared with transport and coalescence models.

中文翻译：

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Au + Au碰撞中氘核定向流的束能量依赖性

我们提供了一阶方位各向异性的度量， $v_{\mathrm{1个}}$来自相对论重离子对撞机（RHIC）的STAR实验记录的Au \ Au碰撞中的氘核，在$ \ ems $ = 7.7、11.5、14.5、19.6、27和39 GeV下记录。对于氘核，$ \ vone $斜率$ \ dvdy | _ {y = 0} $的能量依赖性，其中$ÿ$是速度，提取半中心碰撞（中心度为10-40％）并与质子进行比较。尽管当Geem大于10 GeV时，质子的$ \ vone $斜率通常为负，而氘核的质子的$ \ vone $斜率与零一致，但在最低碰撞能量下，氘核的$ \ vone $斜率会大大增强（$ \ ems = $ 7.7 GeV时的最大重子密度）。此外，我们报告了横向动量的依赖$v_{\mathrm{1个}}$用于质子和氘核。将实验结果与传输和合并模型进行了比较。