The first search for the lepton-flavor violating decays B+→π+μ±e∓ in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of 9 fb-1. No significant signal is observed and an upper limit on the branching fraction is set at B(B+→π+μ±e∓)<1.8×10-9 at the 90% confidence level, 2 orders of magnitude more restrictive than the most stringent upper limit to date. This is the first constraint on lepton-flavor violating b→d quark transitions at the LHC and also sets the most stringent upper limits to date on b→dμ±e∓ transitions. Limits on left-handed and scalar scenarios beyond the standard model are also reported.

Aaij, R., Abdelfatah, M., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., et al. (2026). Search for the Lepton-Flavor Violating Decays B+ →π+μ±e∓. PHYSICAL REVIEW LETTERS, 137(6) [10.1103/ln8k-mlhr].

Search for the Lepton-Flavor Violating Decays B+ →π+μ±e∓

Anelli A.;Arnone L.;Borsato M.;Calvi M.;Capelli S.;Carniti P.;Falcao L. N.;Fazzini D.;Gotti C.;Kirsebom V. S.;Malentacca L.;Martinazzoli L.;Martinelli M.;Minotti A.;Moro A.;Pizzichemi M.;Salomoni M.;
2026

Abstract

The first search for the lepton-flavor violating decays B+→π+μ±e∓ in proton-proton collisions is presented, using data collected by the LHCb experiment between 2011 and 2018, corresponding to an integrated luminosity of 9 fb-1. No significant signal is observed and an upper limit on the branching fraction is set at B(B+→π+μ±e∓)<1.8×10-9 at the 90% confidence level, 2 orders of magnitude more restrictive than the most stringent upper limit to date. This is the first constraint on lepton-flavor violating b→d quark transitions at the LHC and also sets the most stringent upper limits to date on b→dμ±e∓ transitions. Limits on left-handed and scalar scenarios beyond the standard model are also reported.
Articolo in rivista - Articolo scientifico
Branching fractions; Confidence levels; Integrated luminosity; Lefthanded; Lepton-flavor; Level 2; Orders of magnitude; Proton proton collisions; Stringents; Upper limits
English
4-ago-2026
2026
137
6
061802
none
Aaij, R., Abdelfatah, M., Abdelmotteleb, A., Abellan Beteta, C., Abudinen, F., Ackernley, T., et al. (2026). Search for the Lepton-Flavor Violating Decays B+ →π+μ±e∓. PHYSICAL REVIEW LETTERS, 137(6) [10.1103/ln8k-mlhr].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/625045
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