Quasiparton distribution function and quasigeneralized parton distribution of the pion in a spectator model

We study the leading-twist quasi parton distribution function (quasi-PDF) and quasigeneralized parton distribution (quasi-GPD) of the pion meson by using a spectator model. We consider the case where the quasifunctions are defined via inserting the matrix gamma(z) in the spacial correlation functions. We obtain the analytical expressions for the quasi-PDF and quasi-GPD. The numerical results of the quasifunctions are calculated from the parameters obtained by fitting the model result to the known parametrization. Particularly, we investigate the hadron momentum dependence of the quasifunctions as well as compare the quasidistributions to the standard functions at different hadron momentum. We find that in the region x > 0.2, the quasidistribution are similar to the standard distributions in size and shape when the hadron momentum is larger than 2 GeV. Our study thus supports the idea of using quasidistributions to obtain standard distributions.