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 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- / Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 120:22(2018), p. 221803. [10.1103/PhysRevLett.120.221803]

Evidence for the Rare Decay Σ+ →pμ+μ-

Capriotti L.;Casse G.;Sarti A.;Sciubba A.;
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 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.
2018
Spectroscopy Quarkonium Hadron-Hadron Scattering QCD Hard scattering
01 Pubblicazione su rivista::01a Articolo in rivista
Evidence for the Rare Decay Σ+ →pμ+μ- / Aaij, R., Adeva, B., Adinolfi, M., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Alfonso Albero, A., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Andreassi, G., Andreotti, M., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 120:22(2018), p. 221803. [10.1103/PhysRevLett.120.221803]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1310906
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