Implication of possible observation of enhanced Bd0 --> mu+ mu- decay

Understand

The very rare Bd0 --> mu+ mu- decay may be the last chance for New Physics in flavor sector at the LHC, before the 13 TeV run in 2015.

• Partially motivated by the known tension in sin(2beta/phi_1), enhancement beyond (3-4) x 10^-10 would likely imply the effect of a fourth generation of quarks.
• If observed at this level, the 126 GeV boson may not be the actual Higgs boson, while the b --> d quadrangle (modulo m_t') would jump out.
• The 2011-2012 data is likely not sensitive to values below 3 x 10^-10, and the mode should continue to be pursued with the 13 TeV run.