Anatomy of B → PP decays and effects of the next-to-leading order contributions in the perturbative QCD approach

Abstract

By employing the perturbative QCD (PQCD) factorization approach, we made a systematic investigation for the CP-averaged branching ratios and the CP-violating asymmetries of the thirteenB 0 s → P P decays ( here P = (π, K, η, η ′ )) with the inclusion of all currently known next-to-leading order (NLO) contributions, and compared our results with the measured values or the theoretical predictions from other different approaches. We focused on the examination of the effects of the NLO contributions and found the following points:decays, the NLO contributions can provide a (40 − 150)% enhancement or a 20% reduction to the corresponding leading order (LO) PQCD predictions for their decay rates and result in a much better agreement between the PQCD predictions and the experimental measurements; (b) for the pure annihilation decaȳ B 0 s → π + π − , the PQCD prediction still remain consistent with the data after the inclusion of the small NLO reduction; (c) the PQCD predictions for the ratiobecome agree very well with the measured ones after the inclusion of a 40% NLO reduction; (d) for B 0 s → K + K − andB 0 s → π − K + decays, the NLO PQCD predictions for their CP-violating asymmetries do agree very well with the measured values in both the sign and the magnitude; and (e) for allB 0 s → P P decays, we also compared our results with those obtained in the QCD factorization approach and soft-collinear effective theory and discussed their similarities and differences.

Investigating the ratio of CKM matrix elements $|V_{ub}|/|V_{cb}|$ from semileptonic decay $B_s^0\to K^-μ^+ν_μ$ and kaon twist-2 distribution amplitude

“…Furthermore, there are other QM researches on the TFF f B→K + (q 2 ) in literature, such as, the light-front covariant quark model (LFQM) [20] and the light cone quark model (LCQM) within soft collinear effective theory (SCET) [21]. Otherwise, the TFF f B→K + (q 2 ) has also been calculated in some researches on the B/B s two-body decays [22][23][24][25][26].…”

The PQCD approach towards to next-to-leading order: a short review

“…The possible effects of above NLO contributions have been examined in phenomenological studies for many two-body charmless hadronic B (s) → M 1 M 2 decays [132][133][134][135][136][137] and the charmed B (s) → (J/Ψ, η c )(P, V ) decays [138,139], the agreements between the PQCD predictions for the BRs and other physical observables of those considered decay modes with the measured results are improved effectively, some so-called puzzles of B → ππ, Kπ and B → Kη ( ) can be understood better with the NLO correction effects in the PQCD approach.…”