LHCb CollaborationAdeva Andany, BernardoÁlvarez Cartelle, PaulaDosil Suárez, ÁlvaroFernández Albor, Víctor ManuelGallas Torreira, Abraham AntonioHernando Morata, José ÁngelPazos Álvarez, AntonioPérez Trigo, EliseoPlo Casasus, MáximoRodríguez Pérez, PabloRomero Vidal, AntonioSaborido Silva, Juan JoséSantamarina Ríos, CibránSeco Miguélez, Marcos AntonioVázquez Regueiro, PabloVázquez Sierra, Carlos2020-04-302020-04-302014Aaij, R., Adeva, B., Adinolfi, M., Adrover, C., Affolder, A., Ajaltouni, Z., ... & Alkhazov, G. (2014). Search for the decay D0→ π+ π− μ+ μ−. Physics Letters B, 728, 234-2430370-2693http://hdl.handle.net/10347/21919A search for the D0→π+π−μ+μ− decay, where the muon pair does not originate from a resonance, is performed using proton–proton collision data corresponding to an integrated luminosity of 1.0 fb−1 recorded by the LHCb experiment at a centre-of-mass energy of 7 TeV. No signal is observed and an upper limit on the relative branching fraction with respect to the resonant decay mode D0→π+π− φ(→μ+μ− ), under the assumption of a phase-space model, is found to be B D0→π + π − μ + μ − /B D0→π + π − φ →μ + μ − < 0.96 at 90% confidence level. The upper limit on the absolute branching fraction is evaluated to be B(D0→π+π−μ+μ− ) < 5.5×10−7 at 90% confidence level. This is the most stringent to date.eng© 2013 The Authors. Published by Elsevier B.V. Open access under CC BY licensehttps://creativecommons.org/licenses/by/3.0/journal article10.1016/j.physletb.2013.11.0531873-2445open access