Rare beauty and charm decays at LHCb

TL;DR

This paper reviews the latest results from LHCb on rare heavy flavor decays, including measurements of decay rates, angular distributions, and searches for new physics, based on data from 2011-2012.

Contribution

It presents the most precise measurements of certain rare decay processes and reports the first evidence for the decay B_s^0 → μ^+ μ^-, advancing the search for new physics.

Findings

First evidence for B_s^0 → μ^+ μ^- decay

Most stringent upper limits on B^0, D^0, K_s^0 decays to muons

Precise measurements of angular structures in B decays

Abstract

Rare heavy flavor decays are an ideal place to search for the effects of potential new particles that modify the decay rates or the Lorentz structure of the decay vertices. The LHCb experiment, a dedicated heavy flavour experiment at the LHC at CERN. It has recorded the worlds largest sample of heavy meson and lepton decays. The status of the rare decay analyses with 1\,fb$^{-1}$ of $\sqrt s = 7\,$TeV and 1.1\,fb$^{-1}$ of $\sqrt s = 8\,$TeV of $pp$--collisions collected by the LHCb experiment in 2011 and 2012 is reviewed. The worlds most precise measurements of the angular structure of $B^0\rightarrow K^{*0} \mu^+ \mu^-$ and $B^+\rightarrow K^{+} \mu^+ \mu^-$ decays is discussed, as well as the isospin asymmetry measurement in $B\rightarrow K^{(*)} \mu^+ \mu^-}$ decays. The first evidence for the very rare decay $B^0_s \rightarrow \mu^+ \mu^-$ is presented together with the most stringent upper exclusion limits on the branching fraction of decays of $B^0$, $D^0$ and $K^0_s$ mesons into two muons. This note finishes with the discussion of searches for lepton number and lepton flavor violating $\tau$ decays.