SU(3)-Flavor Anatomy of Non-Leptonic Charm Decays

TL;DR

This paper performs an SU(3)-flavor analysis of non-leptonic charm decays, revealing significant SU(3)-breaking effects and suggesting possible new physics contributions to CP violation, with implications for future measurements.

Contribution

It provides a comprehensive SU(3)-flavor framework including symmetry-breaking effects and explores correlations in CP asymmetries to distinguish between different theoretical scenarios.

Findings

SU(3)-breaking effects are around 30% in charm decays.

Enhanced penguin contributions may indicate physics beyond the standard model.

Correlations in CP asymmetries can differentiate underlying dynamics.

Abstract

We perform a comprehensive SU(3)-flavor analysis of charmed mesons decaying to two pseudoscalar SU(3)-octet mesons. Taking into account SU(3)-breaking effects induced by the splitting of the quark masses, m_s != m_{u,d}, we find that existing data can be described by SU(3)-breaking of the order 30%. The requisite penguin enhancement to accomodate all data on CP violation tends to be even larger than the one extracted from Delta a_{CP}^{dir}(K^+K^-,pi^+pi^-) alone, strengthening explanations beyond the standard model. Despite the large number of matrix elements, correlations between CP asymmetries allow potentially to differentiate between different scenarios for the underlying dynamics, as well as between the standard model and various extensions characterized by SU(3) symmetry and its subgroups. We investigate how improved measurements of the direct CP asymmetries in singly-Cabibbo-suppressed decays can further substantiate the interpretation of the data. We show that particularly informative are the asymmetries in D->pi^+pi^- versus D->K^+K^-, D_s->K_S pi^+ versus D^+->K_S K^+, D^+->pi^+ pi^0, D->pi^0pi^0, and D->K_S K_S.