The $D^0 - \bar D^0$ mass difference from a dispersion relation

Abstract

We study the Standard Model prediction for the mass difference between the two neutral D meson mass eigenstates, $Δm$. We derive a dispersion relation based on heavy quark effective theory that relates $Δm$ to an integral of the width difference of heavy mesons, $ΔΓ$, over varying values of the heavy meson mass. Modeling the $m_D$-dependence of certain D decay partial widths, we investigate the effects of SU(3) breaking from phase space on the mass difference. We find that $Δm$ may be comparable in magnitude to $ΔΓ$ in the Standard Model.

16 pages