The $$\sin 2\phi _h$$ sin 2 ϕ h azimuthal asymmetry of pion production in SIDIS within TMD factorization

Abstract

Abstract We study the $$\sin 2\phi _h$$ sin 2 ϕ h azimuthal asymmetry of charged and neutral pion productions off the longitudinally polarized nucleon targets in semi-inclusive deeply inelastic scattering (SIDIS) process within the transverse momentum dependent (TMD) factorization. The asymmetry is contributed by the convolution of the TMD distribution $$h_{1L}^{\perp }$$ h 1 L ⊥ and the Collins fragmentation function $$H_{1}^\perp $$ H 1 ⊥ . We adopt the Wandzura–Wilczek-type (WW-type) approximation for $$h_{1L}^{\perp }$$ h 1 L ⊥ and two different parametrizations on the nonperturbative Sudakov form factor for $$h_{1L}^{\perp }$$ h 1 L ⊥ and $$H_{1}^\perp $$ H 1 ⊥ . We estimate the $$\sin 2\phi _h$$ sin 2 ϕ h asymmetry at HERMES and CLAS and compare them with the corresponding experimental data. We also provide the prediction at kinematical configuration of CLAS12. It is shown that our theoretical calculation can describe the HERMES and CLAS data, except the asymmetry of the $$\pi ^-$$ π - production off proton target at HERMES and CLAS. We also find that different choices of the nonperturbative part of TMD evolution lead qualitatively similar results.