B -> D tau nu Branching Ratios: Opportunity for Lattice QCD and Hadron Colliders

Understand

In the Standard Model, scalar contributions to leptonic and semileptonic decays are helicity suppressed.

• The hypothesis of additional physical neutral/charged Higgses can enhance such scalar contributions and give detectable effects especially in B physics.
• For the charged Higgs, experimental information on both Br(B -> D tau nu) and Br(B -> tau nu) has already become available and in particular the B -> D tau nu branching ratio measurements will be further improved in the coming years.
• Hadronic uncertainties of scalar contributions in semileptonic decays are already in much better shape than the ones plaguing the helicity suppressed leptonic decays B -> tau nu.