CP asymmetries in D→ PP^′ decays

2017/04/14 by Ulrich Nierste, Stefan Schacht, Nierste, Ulrich +1
Physics and Astronomy · #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #Black Holes and Theoretical Physics

paper · pdf · doi:10.48550/arxiv.1704.04523

Abstract

This talk addresses two topics related to CP asymmetries in D meson decays to two pseudoscalar mesons. First I discuss how new physics can be distinguished from the Standard Model through two sum rules relating three direct CP asymmetries each, using the sum rule correlating D⁰→ K⁺K^-, D⁰→ π⁺ π^-, and D⁰→ π⁰ π⁰ for illustration. The other sum rule involves a_CP^dir(D⁺→ K⁰K⁺), a_CP^dir(D_s⁺→ K⁰π⁺), and a_CP^dir(D_s⁺→ K⁺ π⁰). The second topic is the direct CP asymmetry in the decay D⁰ → K_S K_S, which is expected to be large in the Standard Model for two reasons: Flavor-SU(3) symmetry suppresses the tree amplitude which enhances the crucial "penguin-to-tree" ratio and the "penguin" amplitude is dominated by the tree-level W boson exchange between c and u quarks. We find that |a_CP^dir (D⁰ → K_S K_S)| can be as large as 1.1 % in the Standard Model. We advocate D⁰ → K_S K_S as a discovery channel for charm CP violation.

Related

• Charm decays
• \rmSU(3)_F sum rules for CP asymmetry of D_(s) decays
• Direct CP violation in charmed meson decays within the standard model
• Direct CP Violation in D Decays in view of LHCb and CDF Results
• QCD-based estimate of direct CP asymmetry in charm decays