With full 2011 LHC data analyzed, there is no indication for deviation from Standard Model (SM) in CP violating phase for Bs --> J/psi phi, nor in the forward-backward asymmetry for B0 --> K*0 mu+ mu-. SM sensitivity, however, has been reached for Bs --> mu+ mu- rate, and there may be some hint for a suppression. We illustrate that, if a suppressed B(Bs --> mu+ mu-) bears out with 2012 data, it would imply a lower bound on the fourth generation quark mixing product |V_{t's}^*V_{t'b}|.
@article{arxiv.1203.6896,
title = {Hints for a Low Bs --> mu+ mu- Rate and the Fourth Generation},
author = {Wei-Shu Hou and Masaya Kohda and Fanrong Xu},
journal= {arXiv preprint arXiv:1203.6896},
year = {2013}
}