B → Dℓν ℓ form factors beyond leading power and extraction of |V cb | and R(D)

B → Dℓν ℓ form factors beyond leading power and extraction of |V cb | and R(D)

Blog Article

Abstract We investigate the subleading-power corrections to the exclusive B → Dℓν ℓ form factors at O $$ mathcal{O} $$ ( α s 0 $$ {alpha}_s^0 $$ ) in the light-cone sum rules here (LCSR) framework by including the two- and three-particle higher-twist contributions from the B-meson light-cone distribution amplitudes up to the twist-six accuracy, by taking into account the subleading terms in expanding the hard-collinear charm-quark propagator, and by evaluating the hadronic matrix element of the subleading effective current.Employing further the available leading-power results for the semileptonic B → D form factors at the next-to- leading-logarithmic level and combining our improved LCSR predictions with the recent lattice determinations, we then carry out a comprehensive phenomenological analysis on the semi-leptonic B → Dℓν ℓ decay.We extract V cb = 40.

2 − 0.5 + 0.6 th − 1.

4 + 1.4 exp × 10 − 3 V cb = 40.9 − 0.

5 + 0.6 th − 1.0 + 1.

0 cent dyyni exp × 10 − 3 $$ left|{V}_{cb} ight|=left({40.2}_{-0.5}^{+0.

6}{left|{{}_{mathrm{th}}}_{-1.4}^{+1.4} ight|}_{mathrm{exp}} ight) imes {10}^{-3}left(left|{V}_{cb} ight|=left({40.

9}_{-0.5}^{+0.6}{left|{{}_{mathrm{th}}}_{-1.

0}^{+1.0} ight|}_{mathrm{exp}} ight) imes {10}^{-3} ight) $$ using the BaBar (Belle) experimental data, and particularly obtain for the gold-plated ratio R(D) = 0.302 ± 0.

003.