Light-cone distribution amplitudes of axial-vector mesons

Abstract

We have presented a detailed study of twist-2 and twist-3 light-cone distribution amplitudes of 1 P 1 3 and 1 P 1 1 axial-vector mesons, based on QCD conformal partial wave expansion. Applying equations of motion, the twist-three two-parton light-cone distribution amplitudes can be expressed in terms of leading-twist and twist-three three-parton light-cone distribution amplitudes. The relevant G-parity invariant and violating parameters, containing the corrections due to the SU ( 3 ) breaking effects, are evaluated from the QCD sum rule method. The results for axial-vector decay constants of 1 P 1 3 states are presented. The values of tensor decay constants and Gegenbauer moments of the leading twist distribution amplitudes for 1 P 1 1 states are updated. Using Gell-Mann–Okubo mass formula, the mixing angle for the f 8 and f 1 of 1 P 1 3 states is θ P 1 3 ∼ 38 ° , and that for h 8 and h 1 of 1 P 1 1 states is θ P 1 1 ∼ 10 ° . The detailed properties for physical states f 1 ( 1285 ) , f 1 ( 1420 ) , h 1 ( 1170 ) , and h 1 ( 1380 ) are given. Assuming the mixing angle between K 1 A and K 1 B to be θ K = 45 ° or −45°, we also give the detailed study for K 1 ( 1270 ) and K 1 ( 1400 ) . Using the conformal partial wave expansion, we obtain the models for light-cone distribution amplitudes, containing contributions up to conformal spin 9/2. It is interesting to note that some distribution amplitudes have significant asymmetric behaviors, which should be phenomenologically attractive.