Z mediated B - anti-B mixing and B meson CP violating asymmetries in the light of new FCNC bounds

Jun 17, 1991
14 pages
Published in:
  • Phys.Rev.D 45 (1992) 1800-1803
Report number:
  • UCI-TR-91-12

Citations per year

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Abstract: (APS)
We impose new limits on flavor-changing neutral currents (FCNC's) applied to the 4 ± 4 mixing matrix of the next heaviest down quark in a model with extra SU(2)L singlet down quarks, such as in E6. We find the new bounds still allow tree-level FCNC Z exchange to dominate Bd0−B¯d0 mixing, but not Bs0−B¯s0 mixing. A stronger b→d bound by a factor of 1/10 could rule out the possibility of Z mediation with FCNC accounting for Bd0−B¯d0 mixing. The unitarity "d−b triangle" may still be a quadrangle with a detectable fourth side. The CP asymmetries from Bd0 decay should show a new CP-violating phase if the Z-mediated process dominates Bd0−B¯d0 mixing.
  • B0 anti-B0: mixing
  • Z0: exchange
  • exchange: Z0
  • neutral current: flavor changing
  • quark: singlet
  • grand unified theory: E(6)
  • B0: decay modes
  • decay modes: B0
  • CP: violation
  • decay: asymmetry