Search for the lepton-flavour violating decay D0→e±μ∓

R. Aaij , Y. Amhis (1) , S. Barsuk (1) , M. Borsato (1) , O. Kochebina (1) , J. Lefrançois (1) , Y. Li (1) , F. Machefert (1) , G. Manca (1) , R. Quagliani (1) , P. Robbe (1) , M-H. Schune (1) , M. Teklishyn (1) , A. Vallier (1) , B. Viaud (1) , G. Wormser (1) , L. Beaucourt (2) , M. Chefdeville (2) , D. Decamp (2) , N. Déléage (2) , P. Ghez (2) , J.P. Lees (2) , J.F. Marchand (2) , M.N. Minard (2) , B. Pietrzyk (2) , W. Qian (2) , S. t'Jampens (2) , V. Tisserand (2) , E. Tournefier (2) , Z.J. Ajaltouni (3) , M. Baalouch (3) , E. Cogneras (3) , O. Deschamps (3) , I. El Rifai (3) , G. Gazzoni (3) , M. Grabalosa Gándara (3) , Pierre Henrard (3) , M. Hoballah (3) , M. Kozeiha (3) , R. Lefèvre (3) , J. Maratas (3) , S. Monteil (3) , V. Niess (3) , P. Perret (3) , S. Akar (4) , E. Aslanides (4) , J. Cogan (4) , K. De Bruyn (4) , W. Kanso (4) , R. Legac (4) , O. Leroy (4) , G. Mancinelli (4) , M. Martin (4) , A. Mordà (4) , J. Serrano (4) , A. Tayduganov (4) , A. Tsaregorodtsev (4)

1 LAL - Laboratoire de l'Accélérateur Linéaire
2 LAPP - Laboratoire d'Annecy de Physique des Particules
3 LPC - Laboratoire de Physique Corpusculaire - Clermont-Ferrand
4 CPPM - Centre de Physique des Particules de Marseille

A search for the lepton-flavour violating decay D0→e±μ∓ is made with a dataset corresponding to an integrated luminosity of 3.0 fb−1 of proton-proton collisions at centre-of-mass energies of 7 TeV and 8 TeV, collected by the LHCb experiment. Candidate D0 mesons are selected using the decay D∗+→D0π+ and the D0→e±μ∓ branching fraction is measured using the decay mode D0→K−π+ as a normalisation channel. No significant excess of D0→e±μ∓ candidates over the expected background is seen, and a limit is set on the branching fraction, (D0→e±μ∓)<1.3×10−8, at 90 % confidence level. This is an order of magnitude lower than the previous limit and it further constrains the parameter space in some leptoquark models and in supersymmetric models with R-parity violation.

Domaines: Physique des Hautes Energies - Expérience [hep-ex]

R. Aaij, Y. Amhis, S. Barsuk, M. Borsato, O. Kochebina, et al.. Search for the lepton-flavour violating decay D0→e±μ∓. Physics Letters B, 2016, 754, pp. 167-175. ⟨10.1016/j.physletb.2016.01.029⟩. ⟨in2p3-01236676⟩