arXiv subjects

C. W. Winhart

Publications and source records attributed to C. W. Winhart.

2 recordsLinked to original sources

arXiv2000

Predictions on $B \to π\bar{l} ν_l$, $D \to π\bar{l} ν_l$ and $D\to K \bar{l} ν_l$ from QCD Light-Cone Sum Rules

The $f^+$ form factors of the $B\to π$, $D\to π$ and $D\to K$ transitions are calculated from QCD light-cone sum rules (LCSR) and used to predict the widths and differential distributions of the exclusive semileptonic decays $B\to π\bar{l}ν_l$, $D \toπ\bar{l}ν_l$ and $D \to K \bar{l}ν_l$, where $l=e,μ$. The current theoretical uncertainties are estimated. The LCSR results are found to agree with the results of lattice QCD calculations and with experimental data on exclusive semileptonic D decays. Comparison of the LCSR prediction on $B\to π\bar{l} ν_l$ with the CLEO measurement yields a value of |V_{ub}| in agreement with other determinations.

hep-ph↗

arXiv1998

The Scalar $B\to π$ and $D \to π$ Form Factors in QCD

QCD sum rules on the light-cone are derived for the sum $f^+ + f^-$ of the $B\to π$ and $D\to π$ form factors taking into account contributions up to twist four. Combining the results with the corresponding $f^+$ form factors calculated previously by the same method, we obtain the scalar form factors $f^0$. Our sum rule predictions are compared with lattice results, current-algebra constraints, and quark-model calculations. Furthermore, we calculate decay distributions and the integrated width for the semileptonic decay $B \to π\barτν_τ$ which is sensitive to $f^0$. Finally, the dependence of the sum rules on the heavy quark mass and the asymptotic scaling laws are discussed.

hep-ph↗