Branching fractions and CP asymmetries in charm meson decays

Abstract

I present a consistent way to include $\eta$-${\eta }^{\prime }$ mixing in global analyses of two-body decays of heavy hadrons employing the approximate flavour-SU(3) symmetry of QCD. The framework is applied to $D\to P{\eta }^{\prime }$ decays, where $P$ denotes a pseudoscalar meson. The result shows that flavour-SU(3) symmetry holds in the decay rates of these modes to better than 30%. With future data we expect the branching ratios of $D_s\to K^{+}{\eta }^{\prime }$ and $D\to K^{+}{\eta }^{\prime }$ to move upward and downward by $\sim 1\sigma$, respectively. Subsequently I discuss the implications of the LHCb measurements of the CP asymmetries in $D\to K^{+}{K}^{-}$ and $D\to {\pi }^{+}{\pi }^{-}$ for generic scenarios of new physics. New-physics contributions should have imprints on other CP asymmetries as well and can be tested through sum rules. Promising decays are $D_s^{+}\to K^0{\pi }^{+}$, $D^{+}\to {\bar{K}}^0{K}^{+}$, $D^0\to K^0{\bar{K}}^{\ast 0}$, $D^0\to {\bar{K}}^0{K}^{\ast 0}$, $D_s^{+}\to K^{\ast 0}{\pi }^{+}$, and $D^{+}\to {\bar{K}}^{\ast 0}{K}^{+}$.

Comments: plenary talk at DISCRETE 2024 in Ljubljana, 13 pages, 6 figures, submitted to PoS