A search for the rare decay η′→e+e- has been performed with the SND detector at the VEPP-2000 e+e- collider. The inverse reaction e+e-→η′ and η′ five decay chains have been used for this search. The upper limit Γη′→e+e-＜0.002 eV at the 90% confidence level has been set. A sensitivity of SND in a search for η→e+e- decay has been studied. For this purpose a data sample with an integrated luminosity of 108 nb-1 collected in the centerofmass energy range 520580 MeV was analyzed. No background events for the reaction e+e-→η with decay η→π0π0π0 have been found. In the absence of background, a sensitivity to B(η→e+e-) of 10-6 can be reached during two weeks of VEPP-2000 operation.
Abstract
A search for the rare decay η′→e+e- has been performed with the SND detector at the VEPP-2000 e+e- collider. The inverse reaction e+e-→η′ and η′ five decay chains have been used for this search. The upper limit Γη′→e+e-＜0.002 eV at the 90% confidence level has been set. A sensitivity of SND in a search for η→e+e- decay has been studied. For this purpose a data sample with an integrated luminosity of 108 nb-1 collected in the centerofmass energy range 520580 MeV was analyzed. No background events for the reaction e+e-→η with decay η→π0π0π0 have been found. In the absence of background, a sensitivity to B(η→e+e-) of 10-6 can be reached during two weeks of VEPP-2000 operation.
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