Measurement of the B 0 → K ∗0 e + e − branching fraction at low dilepton mass

Abstract

The branching fraction of the rare decay B 0 → K * 0 e + e − in the dilepton mass region from 30 to 1000 MeV/c 2 has been measured by the LHCb experiment, using pp collision data, corresponding to an integrated luminosity of 1.0 fb −1 , at a centre-of-mass energy of 7 TeV. The decay mode B 0 → J/ψ (e + e − )K * 0 is utilized as a normalization channel. The branching fraction B(B 0 → K * 0 e + e − ) is measured to bewhere the first error is statistical, the second is systematic, and the third comes from the uncertainties on the B 0 → J/ψ K * 0 and J/ψ → e + e − branching fractions.

Lattice QCD calculation of form factors describing the rare decaysB→K*ℓ+ℓ−

“…Due to the formulation we use, our results are most accurate when the final-state meson recoils softly, the so-called low-recoil or large q 2 regime. Corresponding experimental measurements have been reported over the past few years, mostly studying B → K Ã l þ l − [3][4][5][6][7][8][9][10][11][12], but also B s → ϕμ þ μ − [13].…”

Averages of b-hadron, c-hadron, and $$\tau $$ τ -lepton properties as of summer 2016

“…T , A Im T , A Re T in the [0.002, 1.120]GeV 2 /c 4 bin of m 2 ( ) [1026], and has also determined the branching fraction in the dilepton mass region [10,1000]MeV/c 2 [1023].…”

Towards the discovery of new physics with lepton-universality ratios of b→sℓℓ decays

“…performed by LHCb, namely of the branching fraction [61], as well as of four angular observables [48] with a reduced form-factor dependence similarly to the muonic case. A fit including the resulting 70 measurements is shown in Fig.…”