Work

Strong D→Dπ and B→Bπ couplings

Year: 2011

Type: article

Abstract: We compute ${g}_{{D}^{*}D\ensuremath{\pi}}$ and ${g}_{{B}^{*}B\ensuremath{\pi}}$ using a framework in which all elements are constrained by Dyson-Schwinger equation studies of QCD and therefore incorporates a consistent, direct, and simultaneous description of light and heavy quarks and the states they may constitute. We link these couplings with the heavy-light-meson leptonic decay constants and thereby obtain ${g}_{{D}^{*}D\ensuremath{\pi}}=15.{9}_{\ensuremath{-}1.0}^{+2.1}$ and ${g}_{{B}^{*}B\ensuremath{\pi}}=30.{0}_{\ensuremath{-}1.4}^{+3.2}$. From the latter, we infer ${\mathrm{g\ifmmode \hat{}\else \^{}\fi{}}}_{B}=0.{37}_{\ensuremath{-}0.02}^{+0.04}$. A comparison between ${g}_{{D}^{*}D\ensuremath{\pi}}$ and ${g}_{{B}^{*}B\ensuremath{\pi}}$ indicates that when the $c$ quark is a system's heaviest constituent, ${\ensuremath{\Lambda}}_{\mathrm{QCD}}/{m}_{c}$-corrections are not under good control.

Source: Physical Review C

DOI: 10.1103/physrevc.83.025205

Authors: Bruno El-Bennich, Mikhail A. Ivanov, Craig D. Roberts