Systematic twist expansion of (eta(c) ,eta(b)) -> gamma*gamma transition form factors in the light-front quark model

作者：Ryu, Hui-Young; Choi, Ho-Meoyng^*; Ji, Chueng-Ryong

来源：PHYSICAL REVIEW D, 2018, 98(3): 034018.

DOI：10.1103/PhysRevD.98.034018

• ASYMPTOTIC-BEHAVIOR
• EXCLUSIVE PROCESSES
• PHOTON

The light-front quark model analysis of the meson-photon transition form factor F-P gamma(Q(2)) amenable both to the spacelike region (Q(2) > 0) and the timelike region (Q(2) < 0) provides a systematic twist expansion of Q(2)F(P gamma)(Q(2)) for the high vertical bar Q(2 vertical bar) region. Investigating F-P gamma(Q(2))(P = eta(c),eta(b)) for the entire kinematic regions of Q(2), we examine the twist-2 and twist-3 distribution amplitudes of (eta(c),eta(b)) mesons in the light-front quark model and quantify their contributions to Q(2)F((eta c,eta b)gamma)(Q(2)). Our numerical results for the normalized transition form factor F-(eta c,F-eta b)gamma(Q(2))/F-(eta c,F-eta b)gamma(0) and the decay width Gamma((eta c,eta b)->gamma gamma) are compared with the available data, checking the sensitivity of our model to the variation of the constituent quark masses.

• 出版日期2018-8-21
• 单位南宁师范大学