Perturbative QCD analysis of neutral B-meson decays into σσ,σf0 and f0f0

• Published in: The European physical journal. C, Particles and fields Particles and fields, 2022-02, Vol.82 (2)
• Main Authors: Niu, Hua-Dian, Li, Guo-Dong, Ren, Jia-Le, Liu, Xin
• Format: Article
• Language: English
• Subjects: Astronomy; Astrophysics and Cosmology; Elementary Particles; Flavor (particle physics); Hadrons; Heavy Ions; Large Hadron Collider; Light; Measurement Science and Instrumentation; Mesons; Nuclear Energy; Nuclear Physics; Particle decay; Physics; Physics and Astronomy; Quantum chromodynamics; Quantum Field Theories; Quantum Field Theory; Quarks; Regular Article - Theoretical Physics; String Theory
• ISSN: 1434-6044; 1434-6052
• DOI: 10.1140/epjc/s10052-022-10111-8

The decays of B d , s 0 → σ σ , σ f 0 , f 0 f 0 , with σ and f 0 denoting the light scalar mesons f 0 ( 500 ) and f 0 ( 980 ) in the two-quark picture, are studied in the perturbative QCD approach based on k T factorization. With the referenced value of the mixing angle | φ | ∼ 25 ∘ for the σ - f 0 mixing in the quark-flavor basis, it is of great interest to obtain that: (a) these neutral B -meson decays into σ σ , σ f 0 , and f 0 f 0 have large branching ratios in the order of 10 - 6 - 10 - 4 , which mean the possibly constructive interferences existed in the decays with different flavor states, and then are expected to be tested at the Large Hadron Collider beauty and/or Belle-II experiments in the (near) future; (b) the large direct CP violations could be easily found in the B d 0 → σ σ , f 0 f 0 and B d , s 0 → σ f 0 decays, which indicate the considerable interferences between the tree and the penguin decay amplitudes involved in these four modes, and would be confronted with the future measurements; (c) these neutral B -meson decays could be examined through the secondary decay chain σ / f 0 → π + π - , namely, the four-body decays of B d , s 0 → ( π + π - ) σ ( f 0 ) ( π + π - ) σ ( f 0 ) with still large branching ratios. On the other side, it seems that other 4 four-body decays of B d 0 → ( π + π - ) σ ( K + K - ) f 0 , B s 0 → ( π + π - ) σ ( f 0 ) ( K + K - ) f 0 , and B s 0 → ( K + K - ) f 0 ( K + K - ) f 0 could also be detected at the relevant experiments, if the f 0 → K + K - could be identified from the ϕ → K + K - clearly. The (near) future experimental confirmations with good precision would help to further study the perturbative and/or nonperturbative QCD dynamics involved in these considered decay modes, as well as to explore the intrinsic characters of these scalar mesons σ and/or f 0 and to constrain both of the magnitude and the sign of φ .