ψ(3770) and B meson exclusive decay B → ψ(3770)K in QCD factorization

Abstract

Belle has observed surprisingly copious production of ψ(3770) in B meson decay B → ψ(3770)K, of which the rate is comparable to that of B → ψ(3686)K. We study this puzzling process in the QCD factorization approach with the effect of S-D mixing considered. We find that the soft scattering effects in the spectator interactions play an essential role. With a proper parametrization for the higher twist soft endpoint singularities associated with kaon, and with the S-D mixing angle θ = −12 • , the calculated decay rates can be close to the data. Implications of these soft spectator effects to other charmonium production in B exclusive decays are also emphasized.

Study of the quasi-two-body decays $$B^{0}_{s} \rightarrow \psi (3770) (\psi (3686))\pi ^+\pi ^-$$ B s 0 → ψ ( 3770 )

“…Table 2 Branching ratios of the quasi-two-decay B 0 s → ψ(3686, 3770) f 0 (→ π + π − ) in the pQCD approach based on two sets of S-D mixing angles, where the uncertainties are similar to the previous ones except the last one, which shows dependence of the mixing angle Comparing with the pure D-wave state, we can notice that the branching ratio of the S-D mixing state for B 0 s → ψ(3770)π + π − will be increased approximately by a factor 2 when the mixing angle is −12 • ; the reason is mainly the small decay constant of ψ(1D), which is compatible with the summaries in Refs. [46,49,[68][69][70]. Moreover, we can observe that the results of the B 0 s → ψ(3686)π + π − change a little comparing with the pure 2S mode when taking the mixing effect into account, so ψ(3686) may be regarded as ψ(2S) state.…”

“…In Ref. [46], the authors make tentative calculations for different mixing solutions of the B meson exclusive decay B → ψ(3770)K with the QCD factorization, and they drew the conclusion that when taking account of higher-twist effects and adopting the S-D mixing angle θ = −(12 ± 2) • (which the widely accepted value), the branching ratio of the decay B → ψ(3770)K can fit the experimental data well. Also, in Refs.…”

Study ofBc→ψ(2S)K,ηDuan1, Yu2 2018Phys. Rev. D3070View full textAdd to dashboardCite

“…It is clear that the branching fraction of the decay mode B c → ψð1 3 D 1 ÞK decreases with the increasing parameter ω 1D , and its change trend becomes slowly as ω 1D ≥ 0.5 GeV, so we take the branching fraction result at ω 1D ¼ 0.5 GeV as the preferred value. In view of the success about the B meson exclusive decay B → ψð3770ÞK [43], we calculate the branching fraction of B c → ψð3770ÞK based on the S-D mixing scheme, whose computations are listed in Table V; of the S-D mixing angle has been introduced in Sec. I.…”

“…But the branching fraction can be raised from 5.88 × 10 −6 to 1.264 × 10 −5 obviously when we adopt the mixing angle θ ¼ −12°, which is consistent with the arguments about mixing angle θ in Refs. [18,19,[43][44][45].…”

Constraints on a new light spin-one particle from rareb→stransitions

“…As for B → ψ ′ K, the data are [22], whereas the only SM prediction of which we are aware is B(B + → ψ ′ K + ) = 4.25 × 10 −4 from Ref. [25], without an error estimate. Since the SM calculations still have considerable uncertainties, after comparing the experimental and SM numbers for [22], we may require…”