New physics in b ! s transitions after LHC run 1 Wolfgang Altmannshofera and David M. Straubb a Perimeter Institute for Theoretical Physics, 31 Caroline St. N, Waterloo, Ontario, Canada N2L 2Y5 b Excellence Cluster Universe, TUM, Boltzmannstr. 2, 85748 Garching, Germany E-mail:
[email protected],
[email protected] We present results of global fits of all relevant experimental data on rare b s decays. We observe significant tensions between the Standard Model predictions! and the data. After critically reviewing the possible sources of theoretical uncer- tainties, we find that within the Standard Model, the tensions could be explained if there are unaccounted hadronic effects much larger than our estimates. Assuming hadronic uncertainties are estimated in a sufficiently conservative way, we discuss the implications of the experimental results on new physics, both model indepen- dently as well as in the context of the minimal supersymmetric standard model and models with flavour-changing Z0 bosons. We discuss in detail the violation of lepton flavour universality as hinted by the current data and make predictions for additional lepton flavour universality tests that can be performed in the future. We find that the ratio of the forward-backward asymmetries in B K∗µ+µ− and B K∗e+e− at low dilepton invariant mass is a particularly sensitive! probe of lepton! flavour universality and allows to distinguish between different new physics scenarios that give the best description of the current data. Contents 1. Introduction2 2. Observables and uncertainties3 2.1. Effective Hamiltonian . .4 2.2. B Kµ+µ− .....................................4 2.3. B ! K∗µ+µ− and B K∗γ ............................6 ! + − ! 2.4.