The Sivers asymmetry in charged Kaon and $$\Lambda $$ hyperon produced SIDIS process at electron ion colliders

Abstract

AbstractWe investigate the single transverse-spin asymmetry with a $$\sin (\phi _h-\phi _S)$$ sin ( ϕ h - ϕ S ) modulation in the charged Kaon produced and in $$\Lambda $$ Λ hyperon produced SIDIS process within the theoretical framework of transverse momentum dependent (TMD) factorization at the next-to-leading-logarithmic order. The asymmetry is contributed by the convolution of Sivers function and the unpolarized fragmentation function $$D_1$$ D 1 for the produced hadron. The parametrization for the proton Qiu–Sterman function, which is closely related to the Sivers function, is adopted to numerically estimate the Sivers asymmetry at the kinematical region of Electron Ion Collider (EIC) and Electron Ion Collider in China (EicC). The TMD evolution of the TMD parton distribution functions are considered by employing the non-perturbative Sudakov form factor. It is found that the predicted Sivers asymmetries $$A_{UT}^{\sin (\phi _h-\phi _S)}$$ A UT sin ( ϕ h - ϕ S ) as functions of x, z and $$P_{hT}$$ P hT are sizable at the kinematical configurations of both EIC and EicC. The strange constituent of the produced charged Kaon and $$\Lambda $$ Λ hyperon in the final state can be a promising probe of the sea quark Sivers function as well as the flavor dependence in the proton target. Therefore, it is important to utilize the future EIC facilities to constrain the sea quark distribution functions as well as the validity of the generalized universality of the Sivers function.