In the quasilinear Regge trajectory ansatz, some useful linear mass inequalities, quadratic mass inequalities and quadratic mass equalities are derived for mesons and baryons. Based on these relations, mass ranges of some mesons and baryons are given. The masses ofbc and ss belonging to the pseudoscalar, vector and tensor meson multiplets are also extracted. The J P of the baryon Ξ + cc (3520) is assigned to be

Based on the light-cone (LC) framework and the k T factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor F Q 2 are recalculated. In particular, the contributions to the pion form factor from the higherhelicity components ( 1 2 1), which come from the spin-space Wigner rotation, are analyzed in the soft and hard energy regions, respectively. Our numerical results show that the right power behavior of the hard contribution from the higher-helicity components can only be obtained by fully keeping the k T dependence in the hard amplitude, and that the k T dependence in LC wave function affects the hard and soft contributions substantially. As an example, we employ a model LC wave function to calculate the pion form factor and then compare the numerical predictions with the experimental data.

We apply the background field method to calculate the moments of the pion two-particles twist-3 distribution amplitude (DA) φ p (ξ) in QCD sum rules. In this paper,we do not use the equation of motion for the quarks inside the pion since they are not on shell and introduce a new parameter m p 0 to be determined. We get the parameter m p 0 ≈ 1.30GeV in this approach. If assuming the expansion of φ p (ξ) in the series in Gegenbauer polynomials C 1/2 n (ξ), one can obtain its approximate expression which can be determined by its first few moments.