Journal of High Energy Physics
In view of the recent LHCb measurement of Delta A(CP), the difference between the time-integrated CP asymmetries in D -> K+K- and D -> pi(+)pi(-) decays, we perform a comparative study of the possible impact of New Physics degrees of freedom on the direct CP asymmetries in singly Cabibbo suppressed D meson decays. We systematically discuss scenarios with a minimal set of new degrees of freedom that have renormalizable couplings to the SM particles and that are heavy enough such that their effects on the D meson decays can be described by local operators. We take into account both constraints from low energy flavor observables, in particular D-0 - (D) over bar (0) mixing, and from direct searches. While models that explain the large measured value for Delta A(CP) with chirally enhanced chromomagnetic penguins are least constrained, we identify a few viable models that contribute to the D meson decays at tree level or through loop induced QCD penguins. We emphasize that such models motivate direct searches at the LHC.
Altmannshofer, W., Primulando, R., Yu, C. T., & Yu, F. (2012). New physics models of direct CP violation in charm decays. Journal of High Energy Physics, 2012(4), 49.