A search for the rare decay Σ^+→pμ^+μ^- is performed using pp collision data recorded by the LHCb experiment at center-of-mass energies sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3 fb^-1. An excess of events is observed with respect to the background expectation, with a signal significance of 4.1 standard deviations. No significant structure is observed in the dimuon invariant mass distribution, in contrast with a previous result from the HyperCP experiment. The measured Σ^+→pμ^+μ^- branching fraction is (2.2_-1.3^+1.8)×10^-8, where statistical and systematic uncertainties are included, which is consistent with the standard model prediction.
Evidence for the Rare Decay Σ^+→pμ^+μ^-
Veltri, M;
2018
Abstract
A search for the rare decay Σ^+→pμ^+μ^- is performed using pp collision data recorded by the LHCb experiment at center-of-mass energies sqrt[s]=7 and 8 TeV, corresponding to an integrated luminosity of 3 fb^-1. An excess of events is observed with respect to the background expectation, with a signal significance of 4.1 standard deviations. No significant structure is observed in the dimuon invariant mass distribution, in contrast with a previous result from the HyperCP experiment. The measured Σ^+→pμ^+μ^- branching fraction is (2.2_-1.3^+1.8)×10^-8, where statistical and systematic uncertainties are included, which is consistent with the standard model prediction.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
