Rare decays of b-hadrons

The LHCb experiment is one of the four major experiments on the Large Hadron Collider (LHC) at CERN. It is specifically designed to study decays of charm- and beauty-hadrons that are produced in copious amounts in the large centre-of-mass energy collisions of the LHC. The ultimate goal of the experiment is to search for evidence that our Standard Model (SM) of particle physics is not a good description of nature. One particularly promising place to look is rare decays of b-hadrons where, at quark level, the b-quark changes flavour into a s- or d-quark and a photon or pair of leptons is produced. These flavour-changing-neutral-current processes can only occur via loop-order Feynman diagrams in the SM. In many extensions of the SM, new heavy particles can contribute in competing Feynman diagrams leading to measurable differences in the rate or angular distribution of the b-hadron decay. During run 1 of the LHC, the LHCb experiment has mainly focussed on processes involving b- to s-quark transitions. This project aims to extend the study of b- to d- quark level processes using the data collected during run 2 of the LHC. These processes are expected to be particularly rare due to the flavour-structure of the SM.