Transverse and spatial structure of light to heavy pseudoscalar mesons in light-cone quark model

Abstract: In this work, we have investigated the transverse and spatial structure of light ($\pi^+ (u\bar d)$, $K^+(u\bar s)$) and heavy ($\eta_c(c\bar c)$, $\eta_b (b\bar b)$, $B$ and $D$) pseudoscalar mesons using the light-cone quark model. The transverse structure of these particles have been studied using the transverse momentum dependent parton distribution (TMDs). The leading twist unpolarized $f_1(x, \mathbf{k}_\perp^2)$ TMD has been solved using the quark-quark correlator. We have predicted the average momenta carried by the quark and antiquark of the considered mesons. For a complete description of mesons, we have also computed the leading twist unpolarized $H(x,0,-t)$ generalized parton distribution (GPD). Further, electromagnetic form factors (EMFFs), along with gravitational form factors (GFFs) have been derived by taking the zeroth and first moments of the unpolarized GPD. These EMFFs are found to be compatible with available lattice simulation results. Further, we have also calculated the parton distribution functions (PDFs) for both the quarks and the antiquarks of these mesons. The PDF sum rule has also been verified.