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Title: Review of Exculsive B to D(*,**)Lnu Decays: Branching Fractions, Form-Factors And |V(Cb|

Abstract

This paper reviews semileptonic decays of B-mesons to states containing charm mesons, i.e., D, D*, D** and possible non-resonant D{sup (*)}{eta}{pi} states as well. The paper covers measurement of branching fractions, form-factors and, most importantly, the magnitude of the CKM matrix element V{sub cb}. I will not attempt a comprehensive review, but will concentrate on reasonably fresh results and consider mostly exclusive measurements. I will also comment on the consistency of the results and what needs to be done to resolve the apparent conflicts.

Authors:
;
Publication Date:
Research Org.:
Stanford Linear Accelerator Center (SLAC)
Sponsoring Org.:
USDOE
OSTI Identifier:
901843
Report Number(s):
SLAC-PUB-12431
hep-ex/0703035; TRN: US0702682
DOE Contract Number:
AC02-76SF00515
Resource Type:
Conference
Resource Relation:
Conference: Contributed to International Conference on Heavy Quarks and Leptons (HQL 06), Munich, Germany, 16-20 Oct 2006
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; B MESONS; FORM FACTORS; LEPTONS; MATRIX ELEMENTS; MESONS; QUARKS; SEMILEPTONIC DECAY; Experiment-HEP,HEPEX

Citation Formats

Snyder, A.E., and /SLAC. Review of Exculsive B to D(*,**)Lnu Decays: Branching Fractions, Form-Factors And |V(Cb|. United States: N. p., 2007. Web.
Snyder, A.E., & /SLAC. Review of Exculsive B to D(*,**)Lnu Decays: Branching Fractions, Form-Factors And |V(Cb|. United States.
Snyder, A.E., and /SLAC. Mon . "Review of Exculsive B to D(*,**)Lnu Decays: Branching Fractions, Form-Factors And |V(Cb|". United States. doi:. https://www.osti.gov/servlets/purl/901843.
@article{osti_901843,
title = {Review of Exculsive B to D(*,**)Lnu Decays: Branching Fractions, Form-Factors And |V(Cb|},
author = {Snyder, A.E. and /SLAC},
abstractNote = {This paper reviews semileptonic decays of B-mesons to states containing charm mesons, i.e., D, D*, D** and possible non-resonant D{sup (*)}{eta}{pi} states as well. The paper covers measurement of branching fractions, form-factors and, most importantly, the magnitude of the CKM matrix element V{sub cb}. I will not attempt a comprehensive review, but will concentrate on reasonably fresh results and consider mostly exclusive measurements. I will also comment on the consistency of the results and what needs to be done to resolve the apparent conflicts.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Apr 02 00:00:00 EDT 2007},
month = {Mon Apr 02 00:00:00 EDT 2007}
}

Conference:
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  • The zero recoil limit of the B{yields}Dl{nu} form factors is calculated on the lattice, which provides a model-independent determination of {vert_bar}V{sub cb}{vert_bar}. Considering a ratio of form factors, in which the bulk of statistical and systematic errors cancel, we obtain a precise result both for h{sub +}(1) and for h{sub -}(1).
  • 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*{sup -}l{sup +}{nu}{sub l} decay in the framework of heavy-quark effective field theory. The results, based on a selected sample of about 52 800 B{sup 0}{yields}D*{sup -}l{sup +}{nu}{sub l} decays, recorded by the BABAR detector, are {rho}{sup 2}=1.157{+-}0.094{+-}0.027, R{sub 1}(1)=1.327{+-}0.131{+-}0.043, R{sub 2}(1)=0.859{+-}0.077{+-}0.021, and F(1)|V{sub cb}|=(34.7{+-}0.4{+-}1.0)x10{sup -3}. The first error is the statistical and the second is the systematic uncertainty. Combining these measurements with the previous BABAR measurement ofmore » the form factors, which employs a different fit technique on a partial sample of the data, we improve the statistical precision of the result, {rho}{sup 2}=1.191{+-}0.048{+-}0.028, R{sub 1}(1)=1.429{+-}0.061{+-}0.044, R{sub 2}(1)=0.827{+-}0.038{+-}0.022, and F(1)|V{sub cb}|=(34.4{+-}0.3{+-}1.1)x10{sup -3}. Using lattice calculations for the axial form factor F(1), we extract |V{sub cb}|=(37.4{+-}0.3{+-}1.2{+-}{sub 1.4}{sup 1.2})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=(4.69{+-}0.04{+-}0.34)%.« less
  • Recent rate measurements of B{sub s}{sup 0} mesons and {Lambda}{sub b}{sup 0} baryons produced in {radical}s = 1.96 TeV proton-antiproton and {Upsilon}(5S) electron-positron collisions are reviewed, including the first observations of six new decay modes: B{sub s}{sup 0} {yields} D{sub s}{sup +} K{sup -} (CDF), B{sub s}{sup 0} {yields} D{sub s}{sup -} D{sub s}{sup +} (CDF), B{sub s}{sup 0} {yields} D{sub s1}{sup -}(2536){mu}{sup +} {nu}{sub {mu}} X (DZero), B{sub s}{sup 0} {yields} {phi}{gamma} (Belle)< {Lambda}{sub b}{sup 0} {yields} p{pi}{sup -} (CDF), and {Lambda}{sub b}{sup 0} {yields} pK{sup -} (CDF). Also examined are branching-fraction measurements or limits for the B{sub s}{supmore » 0} {yields} D{sub s}{sup (*)} D{sub s}{sup (*)} modes (Belle, CDF, and DZero), the B{sub s}{sup 0} {yields} {gamma}{gamma} radiative penguin decay (Belle), and three two-body charmless B{sub s}{sup 0} meson decay channels (CDF). Implications for the phenomenology of electroweak and QCD physics, as well as searches for physics beyond the Standard Model, are identified where applicable.« less
  • The B{sup 0} meson decay modes B{sup 0} --> D*{sup -}p{bar p}{pi}{sup +}, D{sup -}p{bar p}{sup +}, {bar D}*{sup 0}p{bar p}, and B{sup 0} --> {bar D}{sup 0}p{bar p} are studied in a sample of 124 x 10{sup 6} B{bar B} pairs collected with the BABAR detector at the PEP-II collider. The decay of B{sup 0} --> D{sup -}p{bar p}{pi}{sup +} is observed for the first time, with a measured branching fraction B(B{sup 0} --> D{sup -}p{bar p}{pi}{sup +}) = (3.80 {+-} 0.35 {+-} 0.46) x 10{sup -4}. The following branching fractions are also determined: B(B{sup 0} --> D*{sup -}p{barmore » p}{pi}{sup +}) = (5.61 {+-} 0.59 {+-} 0.73) x 10{sup -4}, B(B{sup 0} --> {bar D}*{sup 0} p{bar p}) = (0.67 {+-} 0.21 {+-} 0.09) x 10{sup -4}, and B(B{sup 0} --> {bar D}{sup 0}p{bar p}) = (1.24 {+-} 0.14 {+-} 0.12) x 10{sup -4}. In each decay mode the invariant mass spectra of the charmed mesons and the baryons are compared with a pure phase-space hypothesis in order to gain insight into the B meson decay dynamics. In particular, the Dalitz plots of {bar D}*{sup 0}p versus {bar D}*{sup 0}{bar p} for B{sup 0} --> {bar D}*{sup 0}p{bar p} and of {bar D}{sup 0}p versus {bar D}{sup 0}{bar p} for B{sup 0} --> {bar D}{sup 0}p{bar p} are presented. All results are preliminary.« less