Twist-3 distribution amplitudes of the pion and kaon from the QCD sum rules

Abstract

Twist-3 distribution amplitudes of the pion and kaon are studied in this paper. We calculate the fist several moments for the twist-3 distribution amplitudes (ϕ_{p,σ}^πand ϕ_{p,σ}^K) of the pion and kaon by applying the QCD sum rules. Our results show that, (i) the first three moments of ϕ_p^K and the first two moments of ϕ_p^πand ϕ_σ^{π,K} of the pion and kaon can be obtained with 30% uncertainty; (ii) the fourth moment of the ϕ_p^πand the second moment of the ϕ_σ^K can be obtained when the uncertainty are relaxed to 35%; (iii) the fourth moment of the ϕ_σ^πcan be obtained only when the uncertainty are relaxed to 40%; (iv) we have m_{0π}^p=1.10\pm 0.08 {\rm GeV} and m_{0K}^p=1.25\pm 0.15 {\rm GeV} after including the α_s-corrections to the perturbative part. These moments will be helpful for constructing the twist-3 wave functions of the pion and kaon.