D ∗→Dπ and D ∗→Dγ decays: axial coupling and magnetic moment of D ∗ meson

Damir Bećirević; Benjamin Haas

doi:10.1140/epjc/s10052-011-1734-y

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2024 Impact factor 4.8

Particles and Fields

Eur. Phys. J. C (2011) 71: 1734
https://doi.org/10.1140/epjc/s10052-011-1734-y

Regular Article - Theoretical Physics

D ^∗→Dπ and D ^∗→Dγ decays: axial coupling and magnetic moment of D ^∗ meson

Damir Bećirević^* and Benjamin Haas

Laboratoire de Physique Théorique (Bât. 210), Université Paris Sud, Centre d’Orsay, 91405, Orsay-Cedex, France

^* e-mail: Damir.Becirevic@th.u-psud.fr

Received: 4 July 2011
Published online: 31 August 2011

Abstract

The axial coupling and the magnetic moment of D ^∗-meson or, more specifically, the couplings $g_{D^{\ast}D\pi}$ and $g_{D^{\ast}D\gamma }$ , encode the non-perturbative QCD effects describing the decays D ^∗→Dπ and D ^∗→Dγ. We compute these quantities by means of lattice QCD with N _f=2 dynamical quarks, by employing the Wilson (“clover”) action. On our finer lattice (a≈0.065 fm) we obtain $g_{D^{\ast}D\pi^{+}}=20\pm2$ , and $g_{D^{\ast0} D^{0}\gamma}=2.0\pm 0.6~{\rm GeV}^{-1}$ . This is the first determination of $g_{D^{\ast0} D^{0}\gamma}$ on the lattice. We also provide a short phenomenological discussion and the comparison of our result with experiment and with the results quoted in the literature.