Abstract
Flavor SU(3) symmetry, including 30% first-order SU(3) breaking, has been shown to describe adequately a vast amount of data for charmed meson decays to two pseudoscalar mesons and to a vector and a pseudoscalar meson. We review a recent dramatic progress achieved by applying a high-order perturbation expansion in flavor SU(3) breaking and treating carefully isospin breaking. We identify a class of U-spin related decays to pairs involving charged pseudoscalar or vector mesons, for which high-precision nonlinear amplitude relations are predicted. Symmetry-breaking terms affecting these relations are fourth-order U-spin breaking and terms which are first order in isospin breaking and second order in U-spin breaking. The predicted relations are shown to hold within experimental errors at a precision varying between and , in agreement with estimates of high-order terms. Improved branching ratio measurements for and for decay modes involving three other pairs of charged pseudoscalar and vector mesons could further sharpen two of these precision tests. We also obtain amplitude relations for decays to pairs of neutral pseudoscalar mesons, and relations for rate asymmetries between decays involving and , which hold up to second-order U-spin breaking at a level of several percent.
- Received 19 January 2015
DOI:https://doi.org/10.1103/PhysRevD.91.076007
© 2015 American Physical Society