Scalar mesons in weak semileptonic decays ofB(s)

Abstract

The transition form factors of B (s) → S, with S denoting a scalar meson, are investigated in the light-cone sum rules approach. The numerical values are approximately twice as large as that estimated in the light-front quark model and QCD sum rules approach. Using these form factors, we present the analysis of the decay rates for B → a0(1450)lν l , B → K * 0 (1430)ll, Bs → K * 0 (1430)lν l and Bs → f0(1500)ll with l = e, µ, τ . The results indicate that magnitudes of BR(B0 → a0(1450)lν l ) and BR(Bs → K * 0 (1430)lν l ) can arrive at the order of 10 −4 , which can be measured in the future experiments to clarify the inner structure of scalar mesons. It is also observed that BR(B → K * 0 (1430)τ + τ − ) and BR(Bs → f0(1500)τ + τ − ) are an order of magnitude smaller than the corresponding channels of e + e − and µ + µ − final states due to the heavily suppressed phase space . Moreover, the longitudinal lepton polarization asymmetry for B → K * 0 (1430)ll and Bs → f0(1500)ll are also investigated, whose values are close to −1 for the e + e − and µ + µ − pair except the region close to the end points.

Charmless weakBsdecays in the relativistic quark model

“…Predictions are mostly available for the weak B s decays to scalar K * 0 mesons. Such transitions were studied in the light-cone sum rules [22,24], QCD sum rules [23,26] and perturbative QCD approach [25,27]. We find that our result for the form factor r + (0) is consistent with Ref.…”

“…In Tables V-VII we compare our results for form factors of the weak B s decays to scalar K * 0 , axial vector K 1 and tensor K * 2 mesons at maximum recoil point q 2 = 0 with previous theoretical calculations [17,[22][23][24][25][26][27][28][29]. Predictions are mostly available for the weak B s decays to scalar K * 0 mesons.…”

$$B-S$$ B - S transition form-factors with the light-cone QCD sum rules

“…In Tables 4, 5, 6, 7, we present the B − S transition formfactors from the LCSR [9][10][11][12], the three-point QCD sum rules [13][14][15], and also the results without perturbative O(α s ) corrections in the LCSR. From the Table, we can see that the perturbative O(α s ) corrections are about (15-35) % and (5-20) % for the B − S form-factors with the scalar mesons bellow and above 1 GeV, respectively, we should take them into account consistently.…”

“…The B − S transition form-factors have been calculated with the LCSR [9][10][11][12], the three-point QCD sum rules [13][14][15], the perturbative QCD [16], the light front quark model [17], etc. In Refs.…”

“…In Refs. [9][10][11][12], the B − S form-factors are calculated with the LCSR in the leading order approximation, the perturbative O(α s ) corrections are neglected. Due to the lengthy calculations, only perturbative O(α s ) corrections to the twist-2 and twist-3 terms in the LCSR for the B − P, V form-factors [18][19][20][21][22][23][24][25][26] and perturbative O(α 2 s ) corrections to the twist-2 terms in the LCSR for the B − π form-factor [27] are studied up to now, where the P and V denote the light pseudoscalar and vector mesons, respectively.…”