Two-particle twist-3 distribution amplitudes of the pion and kaon in the light-front quark model

We investigate the two-particle twist-3 distribution amplitudes (DAs) of the pseudoscalar mesons, in particular pseudoscalar [ϕ3;MP(x)] and pseudotensor [ϕ3;Mσ(x)] DAs of the pion and kaon, in the light-front quark model based on the variational principle. We find that the behavior of the conformal symmetry in each meson distribution amplitude depends on the chiral-limit characteristics of the light-front trial wave function taken in the variational principle. We specifically take the two different light-front trial wave functions, Gaussian vs power-law type, and discuss their characteristics of the conformal symmetry in the chiral symmetry limit as well as their resulting degree of the conformal symmetry breaking in ϕ3;MP(x) and ϕ3;Mσ(x) depending on the trial wave function taken in the computation. We present numerical results of transverse moments, Gegenbauer moments and ξ-moments and compare them with other available model estimates. The SU(3) flavor-symmetry breaking effect is also quantified with the numerical computation.