Studies on the decays in the perturbative QCD approach**Research exercises for excellent undergraduate students.

Abstract

The decays are investigated for the first time in the perturbative QCD formalism based on the kT factorization theorem, where the light scalar κ is assumed as a two-quark state. Our numerical results and phenomenological analyses on the CP-averaged branching ratios and CP-violating asymmetries show that: (a) the and decays have large decay rates around , which could be examined by the upgraded large hadron collider beauty and/or Belle-II experiments in the near future; (b) a large decay rate of about appears in the pure annihilation channel, which could provide more evidence to help distinguish different QCD-inspired factorization approaches, even understand the annihilation decay mechanism; (c) the pure penguin modes and would provide a promising ground to search for the possible new physics because of their zero direct and mixing-induced CP violations in the standard model. The examinations with good precision from the future experiments will help to further study the perturbative and/or nonperturbative QCD dynamics involved in these considered decay modes.