Semileptonic $B$ Meson Decays Into A Highly Excited Charmed Meson Doublet

TL;DR

This paper predicts the decay rates and branching ratios of semileptonic B meson decays into highly excited charmed meson doublets using heavy quark effective theory and QCD sum rules.

Contribution

It provides the first estimation of decay rates and branching ratios for B decays into the ($2^{+}$, $3^{+}$) excited charmed mesons at leading order.

Findings

Decay rates are approximately 1.85 and 1.78 x 10^{-19} GeV.

Branching ratios are around 4.6 and 4.4 x 10^{-7}.

Predictions are based on heavy quark expansion and QCD sum rules.

Abstract

We study the heavy quark effective theory prediction for semileptonic $B$ decays into an orbital excited $F$-wave charmed doublet, the ($2^{+}$, $3^{+}$) states ($D^{*'}_{2}$, $D_{3}$), at the leading order of heavy quark expansion. The corresponding universal form factor is estimated by using the QCD sum rule method. The decay rates we predict are $\Gamma_{B\to D^{*'}_{2}\ell\overline{\nu}}=1.85\times10^{-19} {GeV}$ and $\Gamma_{B\to D_{3}\ell\overline{\nu}}=1.78\times10^{-19} {GeV}$. The branching ratios are $\mathcal {B}(B\to D_{2}^{*'}\ell\overline{\nu})=4.6\times10^{-7}$ and $\mathcal {B}(B\to D_{3}\ell\overline{\nu})=4.4\times10^{-7}$, respectively.