Amb motiu del tancament d'estiu, la validació de documents es reprendrà a partir del 28 d'agost de 2026. Disculpeu les molèsties.
Con motivo del cierre de verano, la validación de documentos se reanudará a partir del 28 de agosto de 2026. Disculpad las molestias
Due to the summer closure, document validation will resume starting August 28, 2026. We apologize for any inconvenience.

Tipus de document

Article

Versió

Versió publicada

Data de publicació

Tots els drets reservats

Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/131560

Determination of the form factors for the decay B0→D*−l+νl and of the CKM matrix element |Vcb|

Títol de la revista

Director/Tutor

ISSN de la revista

Títol del volum

Resum

We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element | V c b | and of the parameters ρ 2 , R 1 ( 1 ) , and R 2 ( 1 ) , which fully characterize the form factors for the B 0 → D * − ℓ + ν ℓ decay in the framework of heavy-quark effective field theory. The results, based on a selected sample of about 52 800 B 0 → D * − ℓ + ν ℓ decays, recorded by the BABAR detector, are ρ 2 = 1.157 ± 0.094 ± 0.027 , R 1 ( 1 ) = 1.327 ± 0.131 ± 0.043 , R 2 ( 1 ) = 0.859 ± 0.077 ± 0.021 , and F ( 1 ) | V c b | = ( 34.7 ± 0.4 ± 1.0 ) × 10 − 3 . The first error is the statistical and the second is the systematic uncertainty. Combining these measurements with the previous BABAR measurement of the form factors, which employs a different fit technique on a partial sample of the data, we improve the statistical precision of the result, ρ 2 = 1.191 ± 0.048 ± 0.028 , R 1 ( 1 ) = 1.429 ± 0.061 ± 0.044 , R 2 ( 1 ) = 0.827 ± 0.038 ± 0.022 , and F ( 1 ) | V c b | = ( 34.4 ± 0.3 ± 1.1 ) × 10 − 3 . Using lattice calculations for the axial form factor F ( 1 ) , we extract | V c b | = ( 37.4 ± 0.3 ± 1.2 ± 1.2 1.4 ) × 10 − 3 , where the third error is due to the uncertainty in F ( 1 ) . We also present a measurement of the exclusive branching fraction, B = ( 4.69 ± 0.04 ± 0.34 ) % .

Matèries (anglès)

Citació

Citació

GARRA TICÓ, Jordi, GRAUGÉS POUS, Eugeni and BABAR Collaboration. Determination of the form factors for the decay B0→D*−l+νl and of the CKM matrix element |Vcb|. Physical Review D. 2008. Vol. 77, num. 3, pags. 032002. ISSN 1550-7998. [consulted: 12 of August of 2026]. Available at: https://hdl.handle.net/2445/131560

Exportar metadades

JSON - METS

Compartir registre