Abstract
We have recently seen new upper bounds for , a key decay to search for physics beyond the standard model. Furthermore a nonvanishing decay width difference of the system has been measured. We show that affects the extraction of the branching ratio and the resulting constraints on the new physics parameter space and give formulas for including this effect. Moreover, we point out that provides a new observable, the effective lifetime , which offers a theoretically clean probe for new physics searches that is complementary to the branching ratio. Should the branching ratio agree with the standard model, the measurement of , which appears feasible at upgrades of the Large Hadron Collider experiments, may still reveal large new physics effects.
- Received 12 April 2012
DOI:https://doi.org/10.1103/PhysRevLett.109.041801
© 2012 American Physical Society