Regular Article - Theoretical Physics
Chiral dynamics, S-wave contributions and angular analysis in
INPAC, Shanghai Key Laboratory for Particle Physics and Cosmology, Department of Physics and Astronomy, Shanghai Jiao-Tong University, Shanghai, 200240, China
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Accepted: 23 June 2017
Published online: 7 July 2017
We present a theoretical analysis of the and decays. We construct a general angular distribution which can include arbitrary partial waves of . Retaining the S-wave and P-wave contributions we study the branching ratios, forward–backward asymmetries and a few other observables. The P-wave contribution is dominated by resonance, and the S-wave contribution is analyzed using the unitarized chiral perturbation theory. The obtained branching fraction for , at the order , is consistent with the available experimental data. The S-wave contribution has a branching ratio at the order of , and this prediction can be tested by experiments like BESIII and LHCb. Future measurements can also be used to examine the – scattering phase shift.
© The Author(s), 2017