Charm CP Violation and the Electric Dipole Moments from the Charm Scale

Abstract

The reported CP asymmetry in D->K^+K^- / pi^+pi^- is argued to be too large to naturally fit the SM. If so, a new source of CP violation is implied in the Delta C=1 sector with a milliweak strength. CP-odd interactions in the flavor-diagonal sector are strongly constrained by the EDMs placing severe limitations on the underlying theory. While the largest effects usually come from the New Physics energy scale, they are strongly model-dependent. Yet the interference of the CP-odd forces manifested in D decays with the conventional CP-even Delta C=1 weak interaction generates at the charm scale a background level. It has been argued that the d_n in the SM is largely generated via such an interference, with mild KM-specific additional suppression. The reported CP asymmetry is expected to generate d_n of 30 to 100 times larger than in the SM, or even higher in certain model yet not quite natural examples. In the SM the charm-induced loop-less |d_n| is expected around 10^{-31}e*cm. On the technical side, we present a compact Ward-identity--based derivation of the induced scalar pion-nucleon coupling in the presence of the CP-odd interactions, which appears once the latter include the right-handed light quarks.

29pages, 5 figures

References in corpus (6)

• An Improved Experimental Limit on the Electric Dipole Moment of the Neutron
• Improved limit on the permanent electric dipole moment of 199Hg
• Evidence for CP violation in time-integrated D0 -> h-h+ decay rates
• Implications of the LHCb Evidence for Charm CP Violation
• Repercussions of Flavour Symmetry Breaking on CP Violation in D-Meson Decays
• Direct CP violation in charm and flavor mixing beyond the SM

Cited by in corpus (10)

• P- and T-Violating Lagrangians in Chiral Effective Field Theory and Nuclear Electric Dipole Moments
• D-meson lifetimes within the heavy quark expansion
• On $SU(3{)}_F$ Breaking through Final State Interactions and CP Asymmetries in $D\to PP$ Decays
• A bound on the charm chromo-EDM and its implications
• Parity- and time-reversal-violating nuclear forces
• Neutron and proton electric dipole moments from $N_f=2+1$ domain-wall fermion lattice QCD
• CP violation in D meson decays: would it be a sign of new physics ?
• Time Reversal Violation in Light Nuclei
• Permanent Electric Dipole Moments of Single-, Two-, and Three-Nucleon Systems
• Colored scalars and the neutron electric dipole moment