New physics in Bd,s- ¯ Bd,s mixings and Bd,s → µ + µ − decays

A new way of probing new physics in the B meson system is provided. We define double ratios for the observables of Bd,s- ¯ Bd,s mixings and Bd,s → μ + μ − decays,andfindsimplerelationsbetweentheobservables.By usingtherelationswepredicttheyet-to-be-measuredbranch- ing ratio of Bd → μ + μ − to be (0.809-1.03)×10 −10 ,u p to the new physics models.