Ji Xiangdong, Yuan Feng, Zhao Yong
Tsung-Dao Lee Institute, and Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China.
Maryland Center for Fundamental Physics, Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
Phys Rev Lett. 2017 May 12;118(19):192004. doi: 10.1103/PhysRevLett.118.192004. Epub 2017 May 9.
Applying the connection between the parton Wigner distribution and orbital angular momentum (OAM), we investigate the probe of the gluon OAM in hard scattering processes at the planned electron-ion collider. We show that the single longitudinal target-spin asymmetry in the hard diffractive dijet production is very sensitive to the gluon OAM distribution. The associated spin asymmetry leads to a characteristic azimuthal angular correlation of sin(ϕ_{q}-ϕ_{Δ}), where ϕ_{Δ} and ϕ_{q} are the azimuthal angles of the proton momentum transfer and the relative transverse momentum between the quark-antiquark pair. This study may motivate a first measurement of the gluon OAM in the proton spin sum rule.
应用部分子维格纳分布与轨道角动量（OAM）之间的联系，我们研究了在计划中的电子 - 离子对撞机的硬散射过程中胶子OAM的探测。我们表明，硬衍射双喷注产生中的单纵向靶自旋不对称性对胶子OAM分布非常敏感。相关的自旋不对称性导致了sin(ϕ_q - ϕ_Δ)的特征方位角关联，其中ϕ_Δ和ϕ_q分别是质子动量转移的方位角和夸克 - 反夸克对之间的相对横向动量的方位角。这项研究可能会推动对质子自旋求和规则中胶子OAM的首次测量。
