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

Nov, 2011
4 pages
Published in:
  • Phys.Lett.B 709 (2012) 362-365
  • Published: Mar 23, 2012
e-Print:

Citations per year

20112013201520172019051015
Abstract: (Elsevier)
We investigate the attempt using flavor violation gauge interaction in the up sector to explain the LHCb recently observed large ΔACP ( ACP(D0→K+K−)−ACP(D0→π+π−) ). 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 ΔF=1 and ΔF=2 processes at the hadron colliders as associated top production gc→tZ′ or same-sign top scattering uu→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 ΔACP is completely excluded by the D0–D¯0 mixing. We conclude that the up FCNC type models cannot explain the ΔACP while to be consistent with the D0–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 ΔACP consistently.
Note:
  • 10 pages, 2 figures
  • neutral current: flavor changing
  • up: coupling
  • quark: mixing
  • top: associated production
  • quark: flavor: violation
  • D0 anti-D0: mixing
  • abelian
  • LHC-B