论文标题
测量RHIC上载体介子的全局自旋对齐
Measurement of global spin alignment of vector mesons at RHIC
论文作者
论文摘要
我们报告了$ k^{*0} $，$ \ overline {k^{*0} $，$ k^{*+} $和$ k^{*+} $和$ k^{* - * - * - } $ vector Mesons in Rhic isobar collisions（zr+zr+zr+ru ru ru ru re ru zr+ru ru ru ru ru zr+ru re ru zr+ru， $ \ sqrt {s _ {\ mathrm {nn}}}} $ = 200 GEV。我们观察到重型离子碰撞中的$ k^{*\ pm} $的第一个非零旋转对齐。 $ k^{*\ pm} $ $ρ_{00} $比$ k^{*0} $大的3.9 $σ$大。观察到的差异和$ k^{*\ pm} $和$ k^{*0} $之间的排序是令人惊讶的，并且需要理论的进一步输入。在比较Isobar和Au+Au碰撞之间时，在不确定性中观察到$ k^{*0} $ $ρ_{00} $中的系统大小依赖性。
We report the measurements of spin alignment ($ρ_{00}$) for $K^{*0}$, $\overline{K^{*0}}$, $K^{*+}$, and $K^{*-}$ vector mesons in RHIC isobar collisions (Zr+Zr and Ru+Ru) at $\sqrt{s_{\mathrm {NN}}}$ = 200 GeV. We observe the first non-zero spin alignment for $K^{*\pm}$ in heavy-ion collisions. The $K^{*\pm}$ $ρ_{00}$ is about 3.9$σ$ larger than that of $K^{*0}$. The observed difference and the ordering between $K^{*\pm}$ and $K^{*0}$ are surprising, and require further inputs from theory. When comparing between the isobar and Au+Au collisions, no significant system size dependence in $K^{*0}$ $ρ_{00}$ is observed within uncertainties.
