Determining weak phases from theB→ππ,Kπdecays

Abstract

Recent data of two-body nonleptonic B meson decays allow a topological-amplitude analysis up to the O(λ 2 ) accuracy, where λ denotes the Wolfenstein parameter. We find an exact solution from the B → ππ data and an exact solution from the B → Kπ data, which satisfy the approximate SU(3) flavor symmetry. These solutions indicate that the color-suppressed tree amplitude is large, all other amplitudes can be understood within the standard model, and the weak phases φ 2 ≈ 90 o and φ 3 ≈ 60 o are consistent with the global unitarity triangle fit. *

Revisiting charmless hadronicBu,ddecays in QCD factorization

“…For example, sin 2β ≈ 0.725 was used in the earlier estimate of S f around 2005, while a smaller value of 0.670 is used in the present work. 4 Therefore, it is more sensible to consider the difference…”

“…As a first step, let us consider power corrections to the QCD penguin amplitude of theB → PP decay which has the generic expression where λ (q) p = V pb V * pq with q = s, d, a 4,6 are the effective parameters to be defined below and r P χ is a chiral factor of order unity. Strictly speaking, the penguin contributions associated with the chiral factor r P χ are formerly 1/m b suppressed but chirally enhanced.…”

“…There are several possibilities for a large complex c ′ : either a large complex C ′ or a large complex electroweak penguin P ′ EW or a combination of them. Various scenarios for accommodating large C ′ [4,5,6,7,8,9,10,11] or P ′ EW [12,13] have been proposed. To get a large complex C ′ , one can resort to spectator scattering or final-state interactions (see discussions in Sec.3.E).…”

Hadronic decays of B→a1(1260)b1(1235Jing1, Liu2, Xiao3 2017Phys. Rev. D1000View full textAdd to dashboardCite

“…However, for the modes belonging to the color-suppressed category [46] such as B → J/ψK ( * ) (e.g., see [47][48][49][50]), B 0 → π 0 π 0 (e.g., see [45,[51][52][53][54]), etc., the decay rates estimated in the naive factorization are always too small to be compared with the measurements due to the nearly vanishing Wilson coefficient a 2 ∼ 0. Then the nonfactorizable spectator even weak annihilation amplitudes should be included to clarify the experimental measurements, although they are usually considered as higher order(or power) corrections contributing less in the naive factorization.…”

Quantum Chromodynamics

“…As observed in [99], the NLO corrections, despite of increasing the color-suppressed tree amplitude significantly, are not enough to enhance the B 0 → π 0 π 0 branching ratio to the measured value. A much larger colorsuppressed tree amplitude, about the same order as the color-allowed tree amplitude, must be obtained in order to resolve the puzzle [100,101]. To make sure that the above NLO effects are reasonable, the PQCD formalism has been applied to the B → ρρ decays [99], which also receive the color-suppressed tree contribution.…”