标题： 粒子在非常低的横向动量下在Au+Au碰撞中的能量和中心度依赖性 显示英文标题

标题： Energy and centrality dependence of particle production at very low transverse momenta in Au+Au collisions

摘要： PHOBOS实验在RHIC上具有独特的能力，可以在非常低的横向动量下测量粒子产生。 在200 GeV的Au+Au碰撞中，给出了介子、K介子、质子和反质子的低横向动量不变产率的新结果，这些结果是作为碰撞中心度的函数呈现的，针对最中央的50%事件。 与d+Au碰撞的结果相反，在非常低的$p_{T}$区域没有观察到$m_{T}$标度。 低横向动量产率与从中间横向动量测量的外推结果一致。 对于所有碰撞中心度，观察到横向动量谱的平坦化，这与系统的快速横向膨胀一致。 显示英文摘要

摘要： The PHOBOS experiment at RHIC has the unique capability of measuring particle production at very low transverse momenta. New results on low-transverse momentum invariant yields of pions, kaons, protons and antiprotons in 200 GeV Au+Au collisions are presented as a function of the collision centrality for the 50% most central events. In contrast to the results from d+Au collisions, no $m_{T}$ scaling is observed in the very low $p_{T}$ region. The low transverse momentum yields agree with extrapolations from intermediate transverse momentum measurements. For all collision centralities a flattening of the transverse momentum spectra is observed, consistent with a rapid transverse expansion of the system.