Lawrence Berkeley National Laboratory
New phases inCP-violatingBdecay asymmetries from mixing to singlet down quarks
- Author(s): Choong, Woon-Seng
- Silverman, Dennis
- et al.
Published Web Locationhttps://doi.org/10.1103/physrevd.49.2322
Groups such as E6 with extra SU(2)L singlet down quarks give rise to flavor-changing neutral currents (FCNC's) through the mixing of four or more down quarks. These currents may substantially contribute to the processes of Bd0-B̄d0 and Bs0-B̄s0 mixing, within the allowed range of nonzero values for the four quark mixing parameters. These would then introduce new angles and phases into the CP-violating B decay asymmetries. Other, negative FCNC experiments put limits on these angles. Using a maximum likelihood analysis with contributions from both the standard model and the FCNC's, we find large regions for new physics phases contributing to CP-violating B decay asymmetries. From the bound on the mixing elements, the new singlet down quark might have a mass above the 500 GeV range. © 1994 The American Physical Society.