Abstract
Charged Higgs boson effects are not helicity suppressed in the decays , and could enhance or suppress these modes without violating lepton universality. The present limit of is more stringent than the measurement , while a factor of 2 improvement in the present limit of would be comparable. There is much room for discovery as one pushes the latter limit down to the standard model expectation of order . A value below this may be explained without requiring to be unduly small.
- Received 23 December 1992
DOI:https://doi.org/10.1103/PhysRevD.48.2342
©1993 American Physical Society