Determination of the Form Factors for the Decay B0 to D*- l+ nu_l and of the CKM Matrix Element |Vcb|

Journal Article · Wed Jun 06 04:00:00 EDT 2007 · Physical Review D

OSTI ID:908568

Aubert, B

We present a combined measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| and of the parameters {rho}{sup 2}, R{sub 1}(1), and R{sub 2}(1), which fully characterize the form factors for the B{sup 0} {yields} D*-{ell}+?{sub {ell}} decay in the framework of HQET. The results, based on a selected sample of about 52,800 B{sup 0} {yields} D*-{ell}+?{sub {ell}} decays, recorded by the BABAR detector, are {rho}{sup 2} = 1.156 {+-} 0.094 {+-} 0.028, R{sub 1}(1) = 1.329{+-}0.131{+-}0.044, R{sub 2}(1) = 0.859{+-}0.077{+-}0.022, and F(1)|V{sub cb}| = (35.0{+-}0.4{+-}1.1)x10-3. 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 ?t technique on a partial sample of the data, we improve the statistical precision of the result, {rho}{sup 2} = 1.179 {+-} 0.048 {+-} 0.028,R{sub 1}(1) = 1.417 {+-} 0.061 {+-} 0.044,R{sub 2}(1) = 0.836 {+-} 0.037 {+-} 0.022, and F(1)|V{sub cb}| = (34.7 {+-} 0.3 {+-} 1.1) x 10-3. Using lattice calculations for the axial form factor F(1), we extract |V{sub cb}| = (37.7{+-}0.3{+-}1.2{+-}{sup 1.2}{sub 1.4})x10{sup -3}, where the third error is due to the uncertainty in F(1). We also present a measurement of the exclusive branching fraction, B = (4.77 {+-} 0.04 {+-} 0.39)%.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 908568
• Report Number(s): SLAC-PUB-12511; arXiv:0705.4008
• Journal Information: Physical Review D, Journal Name: Physical Review D; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ACCURACY
DECAY
Experiment-HEP
HEPEX
FORM FACTORS
MATRIX ELEMENTS
STANFORD LINEAR ACCELERATOR CENTER