Electroproduction of the Λ(1520) hyperon
Electroproduction of the Λ(1520) hyperon
复制标题
Λ(1520) 超子的电产生
DOI：
10.1103/physrevc.64.044601
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发表时间：
2001
期刊：
影响因子：
--
通讯作者：
E. al.
中科院分区：
文献类型：
--
作者：
S. Barrow;E. al.
利用Thomas Jefferson国家加速器设施的CLAS探测器，在电子束能量为4.05、4.25和4.46 GeV的情况下，研究了ep{产率}e'K{sup +}{Lambda}（1520）和{Lambda}(1520){产率}p'K{sup -}的反应。在运动区域0.9<Q{sup 2}<2.4 GeV{sup 2}和1.95<W<2.65 GeV时，给出了{Lambda}（1520）电生产的cos {theta}{sub K{sup +}}、{phi}{sub K{sup +}}、Q{sup 2}和W依赖关系。此外，首次提出了{Lambda}（1520）衰减角分布的Q{sup 2}依赖性。cos {theta}{sub K{sup +}}角分布表明t通道图主导了生产过程。对{Lambda}(1520) t通道螺旋框架衰减角分布的拟合表明，m{sub z}={+-}1/2亲代约占总产率的60%，这表明该反应的重要贡献来自于K{sup +}交换或与交换K{sup *}的纵向耦合。{Lambda}（1520）生产截面的Q{sup 2}依赖性与{Lambda}（1116）光电生产截面的Q{sup 2}依赖性相同。
The reaction ep{yields}e'K{sup +}{Lambda}(1520) with {Lambda}(1520){yields}p'K{sup -} was studied at electron beam energies of 4.05, 4.25, and 4.46 GeV, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cos {theta}{sub K{sup +}}, {phi}{sub K{sup +}}, Q{sup 2}, and W dependencies of {Lambda}(1520) electroproduction are presented for the kinematic region 0.9<Q{sup 2}<2.4 GeV{sup 2} and 1.95<W<2.65 GeV. Also, the Q{sup 2} dependence of the {Lambda}(1520) decay angular distribution is presented for the first time. The cos {theta}{sub K{sup +}} angular distributions suggest t-channel diagrams dominate the production process. Fits to the {Lambda}(1520) t-channel helicity frame decay angular distributions indicate the m{sub z}={+-}1/2 parentage accounts for about 60% of the total yield, which suggests this reaction has a significant contribution from t-channel processes with either K{sup +} exchange or longitudinal coupling to an exchanged K{sup *}. The Q{sup 2} dependence of the {Lambda}(1520) production cross section is the same as that observed for {Lambda}(1116) photo- and electroproduction.