Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Measurement of B -> D* Form Factors in the Semileptonic Decay B -> D* l nu

Technical Report ·
DOI:https://doi.org/10.2172/833017· OSTI ID:833017
The authors present a preliminary measurement of R{sub 1}, and R{sub 2}, and {rho}{sup 2}, which are the three parameters used to characterize the B {yields} D*{ell}{bar {nu}}{sub e} form factors (A{sub 1}, V, and A{sub 2}). They use 85 x 10{sup 6} B{bar B}-pairs accumulated on the {Upsilon}(4S) resonance at PEP-II. In this analysis they use the decay mode {bar B}{sup 0} {yields} D{sup +}*e{sup -}{bar {nu}} and its charge conjugate. The D*{sup +} is reconstructed in the channel D*{sup +} {yields} D{sup 0}{pi}{sup +} and the D{sup 0} in the channel D{sup 0} {yields} K{sup -}{pi}{sup +}. They parameterize the form factors in terms of their ratios (determined by the parameters R{sub 1} and R{sub 2}) and the common slope {rho}{sup 2} in the variable w (a quantity related to the momentum transfer in the decay process). These parameters are determined via an unbinned maximum likelihood fit to the distributions in four kinematic variables (three decay angles and w). The results are R{sub 1} = 1.328 {+-} 0.055 {+-} 0.025 {+-} 0.025 and R{sub 2} = 0.920 {+-} 0.044 {+-} 0.020 {+-} 0.013 for the ratios and {rho}{sup 2} = 0.769 {+-} 0.l039 {+-} 0.019 {+-} 0.032 for the slope. The stated errors are the statistical uncertainty from the data, statistical uncertainty from the size of the Monte Carlo sample and the systematic uncertainty, respectively.
Research Organization:
Stanford Linear Accelerator Center, Menlo Park, CA (US)
Sponsoring Organization:
USDOE Office of Science (US)
DOE Contract Number:
AC03-76SF00515;
OSTI ID:
833017
Report Number(s):
SLAC-PUB-10612
Country of Publication:
United States
Language:
English