Measurement of Semileptonic B Decays Into Orbitally-Excited Charm Mesons

Le résumé fourni par la source

The authors present a study of B decays into semileptonic final states containing charged and neutral D{sub 1}(2420) and D*{sub 2}(2460). The analysis is based on a data sample of 208 fb{sup -1} collected at the {Upsilon}(4S) resonance with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. With a simultaneous fit to four different decay chains, the semileptonic branching fractions are extracted from measurements of the mass difference {Delta}m = m(D**)-m(D) distributions. Product branching fractions are determined to be {Beta}(B{sup +} {yields} D{sub 1}{sup 0}{ell}{sup +}{nu}{sub {ell}}) x {Beta}(D{sub 1}{sup 0} {yields} D*{sup +}{pi}{sup -}) = (2.97 {+-} 0.17 {+-} 0.17) x 10{sup -3}, {Beta}(B{sup +} {yields} D*{sub 2}{sup 0}{ell}{sup +}{nu}{sub {ell}}) x {Beta}(D*{sub 2}{sup 0} {yields} D{sup (*)+} {pi}{sup -}) = (2.29 {+-} 0.23 {+-} 0.21) x 10{sup -3}, {Beta}(B{sup 0} {yields} D{sub 1}{sup -}{ell}{sup +}{nu}{sub {ell}}) x {Beta}(D{sub 1}{sup -} {yields} D*{sup 0}{pi}{sup -}) = (2.78 {+-} 0.24 {+-} 0.25) x 10{sup -3} and {Beta}(B{sup 0} {yields} D*{sub 2}{sup -}{ell}{sup +}{nu}{sub {ell}}) x {Beta}(D*{sub 2}{sup -} {yields} D{sup (*)0} {pi}{sup -}) = (1.77 {+-} 0.26 {+-} 0.11) x 10{sup -3}. In addition they measure the branching ratio {Lambda}(D*{sub 2} {yields} D{pi}{sup 0})/{Lambda}(D*{sub 2} {yields} D{sup (*)}{pi}{sup -}) = 0.62 {+-} 0.03 {+-} 0.02.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.