Can Up FCNC solve the $\Delta A_{CP}$ puzzle?

Abstract

We investigate the attempt using flavor violation gauge interaction in the up sector to explain the LHCb recently observed large $\Delta A_{CP}$ ($A_{CP}(D^0\to K^{+}{K}^{-})-A_{CP}(D^0\to {\pi }^{+}{\pi }^{-})$). We study an Abelian model that only right-handed up quarks is charged under it and the 1-3 coupling is maximized. The simultaneous 1-3 2-3 mixing is realized by a quark mixing of 1-2 generation. Given the easy identification of top quark, the model can be directly tested by $\Delta F=1$ and $\Delta F=2$ processes at the hadron colliders as associated top production $gc\to t{Z}^{\prime }$ or same-sign top scattering $uu\to tt$. The direct search bounds are still consistent with the assumption that $ut$ and $ct$ couplings are equal but the same-sign top scattering bound is expected to be reached very soon. However, since there is no CKM-like suppression, the corresponding parameter space for generating $\Delta A_{CP}$ is completely excluded by the $D^0-{\bar{D}}^0$ mixing. We conclude that the up FCNC type models cannot explain the $\Delta A_{CP}$ while to be consistent with the $D^0-{\bar{D}}^0$ mixing constraint at the same time. On the other hand, a model as SM with fourth family extension has better chance to explain the large $\Delta A_{CP}$ consistently.

10 pages, 2 figures

References in corpus (2)

• New Physics and CP Violation in Singly Cabibbo Suppressed D Decays
• Top quark asymmetry from a non-Abelian horizontal symmetry

Cited by in corpus (20)

• Size of direct CP violation in singly Cabibbo-suppressed D decays
• On Partial Compositeness and the CP asymmetry in charm decays
• A consistent picture for large penguins in D -> pi+ pi-, K+ K-
• CP asymmetries in singly-Cabibbo-suppressed $D$ decays to two pseudoscalar mesons
• SU(3) symmetry breaking and CP violation in D -> PP decays
• SU(3) Sum Rules for Charm Decay
• Revisiting CP violation in $D\to PP$ and $VP$ decays
• Testing for new physics in singly Cabibbo suppressed D decays
• New Physics Models of Direct CP Violation in Charm Decays
• On $SU(3{)}_F$ Breaking through Final State Interactions and CP Asymmetries in $D\to PP$ Decays
• Direct CP violation in beauty and charm hadron decays
• CP violation in D meson decays: would it be a sign of new physics ?
• Brief Review of Charm Physics
• Direct CP Violation in D Decays in view of LHCb and CDF Results
• Asymmetric Origin for Gravitino Relic Density in the Hybrid Gravity-Gauge Mediated Supersymmetry Breaking
• Nonleptonic Charm Decays and CP Violation
• Nonuniversality of indirect CP asymmetries in $D\to \pi \pi ,KK$ decays
• A search for time-integrated CP violation in D0 -> h- h+ decays
• Direct CP Violation in D -> hh Decays
• Up-type FCNC in presence of Dark Matter