Study of $$\Lambda _b\rightarrow \Lambda (\phi ,\eta ^{(\prime )})$$ Λ b → Λ ( ϕ , η ( ′ ) ) and $$\Lambda _b\rightarrow \Lambda K^+K^-$$ Λ b → Λ K + K - decays

Abstract

We study the charmless two-body b → (φ, η ( ) ) and three-body b → K + K − decays. We obtain B( b → φ) = (3.53 ± 0.24) × 10 −6 to agree with the recent LHCb measurement. However, we find that B( b → η ), given by the previous study.

Semileptonic and nonleptonic weak decays of Λb0

“…BðΛ 0 b → ΛηÞ ¼ 2.95 × 10 −6 , BðΛ 0 b → Λη 0 Þ ¼ 3.24 × 10 −6 , and R Λ ηη 0 ¼ 0.91, for form factors calculated in a pole model. Another study also uses the generalized factorization approach [8], and the results are: BðΛ 0 b → ΛηÞ ¼ ð1.47 AE 0.35Þ × 10 −6 , BðΛ 0 b → Λη 0 Þ ¼ ð1.83 AE 0.58Þ × 10 −6 , and R Λ ηη 0 ¼ 0.80 AE 0.32. One can see a large difference in predictions between different approaches.…”

“…The reason leads to the difference may be: (1) Anomaly contribution. In [8], one effect of anomaly term is introduced in the ηðη 0 Þ decay constants. (2) a 6 and a 8 contributions.…”

“…Our theory prediction is BðΛ 0 b → ΛϕÞ ¼ ð5-7Þ × 10 −7 which is smaller than the data. By comparison, the result in [8] using the generalized factorization approach gives BðΛ 0 b → ΛϕÞ ¼ ð3.53 AE 0.24Þ × 10 −6 when the number of color is chosen as N eff c ¼ 2. Why our theory prediction is smaller than the data?…”

“…The LHC run II [3] and the possible future upgrade of LHC will accumulate more data than ever, we expect that the study of Λ 0 b will enter into a precise era. Theoretical interests on Λ 0 b decays were increased recently, such as light-front quark model [4,5], QCD factorization (QCDF) approach [6], generalized factorization approach (GFA) [7][8][9], light-cone sum rules [10], lattice QCD method [11], soft-collinear-effective-theory (SCET) approach [12], perturbative QCD (pQCD) approach [13], SU(3) symmetry relations [14], etc. In the previous works [4][5][6], we have calculated the weak decay of Λ 0 b with the light-front quark model, diquark approximation and factorization assumption.…”

Determinations of $$|V_{cb}|$$ | V c b | and $$|V_{ub}|$$ | V u b | from baryonic $$\Lambda _b$$ Λ b decays

“…In the two-body B meson decays, this empirical estimation has been demonstrated to agree with the sub-leading calculations like the QCD factorization [23][24][25], where the similar a 1 is modified by the detailed calculation for the non-factorizable effects but with the number to fall into the allowed range with N eff c from 2 to ∞ in the generalized version of the factorization [20]. While the theory depends on the data to test its validity, in the b decays the generalized factorization has been used to explain the data well [19,[26][27][28][29]. However, it is clear that the sub-leading calculations for the non-factorizable effects have not been well developed in b → c M (c) yet.…”