Semi-inclusive π 0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS
Semi-inclusive π 0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS
复制标题
使用 CLAS 实现 6 GeV 电子散射的半包容 δ 0 目标和束目标不对称性
DOI：
10.1016/j.physletb.2018.06.014
复制
发表时间：
2018
影响因子：
4.4
通讯作者：
Adikaram, D.
中科院分区：
文献类型：
--
作者：
Jawalkar, S.;Koirala, S.;Avakian, H.;Bosted, P.;Griffioen, K.A.;Keith, C.;Kuhn, S.E.;Adhikari, K.P.;Adhikari, S.;Adikaram, D.
我们提出了精确测量的目标和光束目标的自旋不对称性从中性π介子电产生深度非弹性散射（DIS）使用的CEBAF大接受光谱仪（CLAS）在杰斐逊实验室。在低温14NH3靶中，我们用6GeV的纵向极化电子与纵向极化质子散射，在四动量转移的多维仓中提取了ep→ e′ π 0X的双靶和单靶自旋不对称性（1.0<Q2 <3.2GeV2），Bjorken x（0.12< x< 0.48），强子能量分数（0.4< z< 0.7），横π动量（0<PT <1.0GeV），轻子散射面与强子产生面之间的方位角θ h。我们提取的不对称性作为一个函数的x和PT，这提供了纵向极化夸克的横向动量分布。双自旋不对称性对PT的依赖很弱。在不确定性范围内，sin 2 π h矩为零，这与预期的柯林斯碎裂函数的抑制是一致的。观察到的sin π矩表明，夸克胶子关联在大x时是显著的。
We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic 14 NH 3 target, and extracted double and single target spin asymmetries for ep→ e′ π 0 X in multidimensional bins in four-momentum transfer (1.0< Q 2< 3.2 GeV 2), Bjorken-x (0.12< x< 0.48), hadron energy fraction (0.4< z< 0.7), transverse pion momentum (0< P T< 1.0 GeV), and azimuthal angle ϕ h between the lepton scattering and hadron production planes. We extracted asymmetries as a function of both x and P T, which provide access to transverse-momentum distributions of longitudinally polarized quarks. The double spin asymmetries depend weakly on P T. The sin 2ϕ h moments are zero within uncertainties, which is consistent with the expected suppression of the Collins fragmentation function. The observed sin ϕ h moments suggest that quark gluon correlations are significant at large x.