Polarizations of J/ψ and ψ(2S) mesons produced in p(p)over-bar collisins at √s-1.96 TeV
Polarizations of J/ψ and ψ(2S) mesons produced in p(p)over-bar collisins at √s-1.96 TeV
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DOI：
10.1103/physrevlett.99.132001
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发表时间：
2007-09-28
影响因子：
8.6
通讯作者：
Zucchelli, S.
中科院分区：
文献类型：
--
作者：
Abulencia, A.;Adelman, J.;Zucchelli, S.
当 J/psi 和 psi(2S) 介子在 p(T)>= 5 GeV/c 的快速范围 |y|< 0.6 内迅速产生时，我们测量了 J/psi 和 psi(2S) 介子的极化作为其横向动量 p(T) 的函数。使用 CDF II 检测器收集的积分光度约为 800 pb(-1) 的数据样本进行分析。对于这两个矢量介子，我们发现随着 p(T) 从 5 GeV/c 增加到 30 GeV/c，极化变得越来越纵向。这些结果与非相对论量子色动力学和其他当代模型的预测进行了比较。还报道了来自 B 强子衰变的 J/psi 和 psi(2S) 介子的有效极化。
We have measured the polarizations of J/psi and psi(2S) mesons as functions of their transverse momentum p(T) when they are produced promptly in the rapidity range |y|< 0.6 with p(T)>= 5 GeV/c. The analysis is performed using a data sample with an integrated luminosity of about 800 pb(-1) collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as p(T) increases from 5 to 30 GeV/c. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of J/psi and psi(2S) mesons from B-hadron decays are also reported.