https://doi.org/10.1140/epjc/s2004-01872-7
theoretical physics
CP asymmetry in 
in a general two-Higgs-doublet model with fourth-generation quarks
1
Institute of Theoretical Physics, Chinese Academy of Sciences, P.O. Box 2735, 100080, Beijng, P.R. China
2
Institute for Physics, Dortmund University, 4221, Dortmund, Germany
* e-mail: ylwu@itp.ac.cn
We discuss the time-dependent CP asymmetry of the decay 
in an extension of the standard model with both a two Higgs doublet and additional fourth-generation quarks. We show that, although the standard model with a two Higgs doublet and the standard model with fourth-generation quarks alone are not likely to largely change the effective 
from the decay , the model with both an additional Higgs doublet and fourth-generation quarks can easily account for the possible large negative value of without conflicting with other experimental constraints. In this model, additional large CP violating effects may arise from the flavor-changing Yukawa interactions between neutral Higgs bosons and the heavy fourth-generation down type quark, which can modify the QCD penguin contributions. With the constraints obtained from 
processes such as 
and 
, this model can lead to an effective as large as - 0.4 in the CP asymmetry of 
.
© Springer-Verlag, 2004
