Status of the $$B\rightarrow K^*\mu ^+\mu ^-$$ B → K ∗ μ +

Abstract

Motivated by recent results by the ATLAS and CMS collaborations on the angular distribution of the B → K * μ + μ − decay, we perform a state-of-the-art analysis of rare B meson decays based on the b → sμμ transition. Using standard estimates of hadronic uncertainties, we confirm the presence of a sizeable discrepancy between data and SM predictions. We do not find evidence for a q 2 or helicity dependence of the discrepancy. The data can be consistently described by new physics in the form of a four-fermion contact interaction (sγ α P L b)(μγ α μ). Assuming that the new physics affects decays with muons but not with electrons, we make predictions for a variety of theoretically clean observables sensitive to violation of lepton flavour universality.

Lepton-flavor universality limits in warped space

“…[14][15][16]. As experimental data favor ∆C µ 9 −∆C µ 10 , we have fixed c µ R = 0.5 which pro-vides the latter relation.…”

“…Using the recent multi-observable fit (which includes R K ( * ) ) from Refs. [14,16] we get the 2σ interval ∆C (15) …”

Two Higgs doublet models and $$b\rightarrow s$$ b → s exclusive decays

“…The spectrum of dB(B → K μ + μ − )/dq 2 has been measured [3] too and in the range of large q 2 's it appears to be larger than predicted [4][5][6][7][8][9]. A full angular analysis of B(B → K * μ + μ − ) [3,10] and B(B s → φμ + μ − ) [11] revealed discrepancies in several observables with respect to their SM predictions [12][13][14][15][16][17][18][19]. Moreover, the recent measurements of R K = B (B → K μ + μ − )/B (B → K e + e − ) [20] and R K * = B (B → K * μ + μ − )/B (B → K * e + e − ) [21] were shown to be significantly lower than predicted [22].…”

In pursuit of new physics with B s,d 0 → ℓ + ℓ −

“…[20]). Data for B → K ( * ) e + e − modes allows us also to take a possible violation of Lepton Flavour Universality into account.…”