S-wave resonance contributions to in the perturbative QCD factorization approachSupported by National Natural Science Foundation of China (11235005, 11547038)
Ai-Jun Ma (Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China); Ya Li (Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China); Wen-Fei Wang (Institute of Theoretical Physics, Shanxi University, Taiyuan, Shanxi 030006, China); Zhen-Jun Xiao (Department of Physics and Institute of Theoretical Physics, Nanjing Normal University, Nanjing 210023, China, Jiangsu Key Laboratory for Numerical Simulation of Large Scale Complex Systems, Nanjing Normal University, Nanjing 210023, China)
By employing the perturbative QCD (PQCD) factorization approach, we study the quasi-two-body decays, where the pion pair comes from the S-wave resonance f0(X). The Breit–Wigner formula for the f0(500) and f0(1500) resonances and the Flatté model for the f0(980) resonance are adopted to parameterize the time-like scalar form factors in the two-pion distribution amplitudes. As a comparison, Bugg's model is also used for the wide f0(500) in this work. For decay rates, we found the following PQCD predictions: (a) when the contributions from f0(980) and f0(1500) are all taken into account; (b) in the Breit-Wigner model and in Bugg's model.
