Implications of the LHCb Evidence for Charm CP Violation

Understand

The LHCb collaboration recently announced preliminary evidence for CP violation in D meson decays.

• We discuss this result in the context of the standard model (SM), as well as its extensions.
• In the absence of reliable methods to evaluate the hadronic matrix elements involved, we can only estimate qualitatively the magnitude of the non-SM tree level operators required to generate the observed central value.
• In the context of an effective theory, we list the operators that can give rise to the measured CP violation and investigate constraints on them from other processes.