%0 Generic
%A Mitzel, Dominik
%D 2019
%F heidok:25790
%R 10.11588/heidok.00025790
%T Search for new physics in rare four-body charm decays
%U https://archiv.ub.uni-heidelberg.de/volltextserver/25790/
%X This dissertation presents a search for physics beyond the Standard Model in D0->π+π-μ+μ−und D0->K+K−μ+μ− decays at the LHCb experiment. These rare four-body decays of neutral charm mesons receive contributions from electroweak flavour-changing neutral current c->ul+l− transitions and are unique probes for potential new heavy degrees of freedom and for additional sources of CP violation in the up-type quark sector. Using a sample of proton-proton collisions corresponding to an integrated luminosity of 2 fb−1 recorded at a center-of-mass energy of 8TeV in 2012, the first observation of D0->π+π-μ+μ−und D0->K+K−μ+μ− decays is reported. Furthermore, their branching fractions are measured. With an increased data set, corresponding to an integrated luminosity of 5 fb−1 and recorded at center-of-mass energies of 7, 8 and 13TeV in the years 2011-2016, the first measurement of the CP asymmetry ACP , the forward-backward asymmetry in the lepton system AFB and the triple-product asymmetry A2ϕ in these decays is presented. All observables are also investigated as functions of the dimuon mass. The results are consistent with Standard Model predictions.