Measurement of the {bar B}{sup 0} --> D*{sup +} {ell}{sup -} {bar {nu}}{sub {ell}} Decay Rate and |V{sub cb}|

Abstract

The authors present a measurement of the Cabibbo-Kobayashi-Maskawa matrix element |V{sub cb}| based on a sample of about 53,700 {bar B}{sup 0} --> D*{sup +}{ell}{sup -}{bar {nu}}{sub {ell}} = (4.90 {+-} 0.07(stat.){sub -0.35}{sup +0.36}(syst.))%. They measure the differential decay rate as a function of w, the relativistic boost {gamma} of the D*{sup +} in the {bar B}{sup 0} rest frame. By extrapolating d{Gamma}/dw to the kinematic limit w {yields} 1, the authors extract the product of |V{sub cb}| and the axial form factor A{sub 1}(w = 1) to determine |V{sub cb}| = (38.7 {+-} 0.3(stat.) {+-} 1.7(syst.){sub -1.3}{sup +1.5}(theory)) x 10{sup -3}.