The result of a search for high mass photon pairs from the processes e+ e- -> f fbar gamma gamma(f = e, mu, tau, nu and q) with the ALEPH detector is reported. The result for f = e, mu and tau is to be compared with the observation of 4 events by the L3 Collaboration with invariant masses, M(gamma gamma), of the two photons near 60 GeV. From a data sample approximately twice as large taken from 1990 to 1992, 6 events are found with M(gamma gamma) distributed between 50 GeV and 72 GeV, while 4.9 events are expected from a QED calculation. There is no evidence for a mass peak; only one event (mu+ mu- gamma gamma) at M(gamma gamma) = 59.4 +/- 0.2 GeV is compatible with the L3 observation. In addition, for M(gamma gamma) > 50 GeV, no event is found for e+e- -> q qbar gamma gamma and only one event is found consistent with e+e- -> nu nubar gamma gamma; this event has M(gamma gamma) = 58.5 +/- 1.9 GeV. High mass photon pair events have also been searched for in gamma gamma collisions. This allows one to set an upper limit of 50 MeV for the width of an assumed resonance decaying to photon pairs.

D., B., I., D., D., D., P., G., C., G., J. P., L., et al. (1993). Search For High-mass Photon Pairs In e+e->f fbar gamma-gamma (f = e, mu,tau, nu, q) At Lep. PHYSICS LETTERS. SECTION B, 308(3-4), 425-434 [10.1016/0370-2693(93)91308-A].

Search For High-mass Photon Pairs In e+e->f fbar gamma-gamma (f = e, mu,tau, nu, q) At Lep

BOTTIGLI, UBALDO;CIOCCI, MARIA AGNESE;MARROCCHESI, PIER SIMONE;
1993-01-01

Abstract

The result of a search for high mass photon pairs from the processes e+ e- -> f fbar gamma gamma(f = e, mu, tau, nu and q) with the ALEPH detector is reported. The result for f = e, mu and tau is to be compared with the observation of 4 events by the L3 Collaboration with invariant masses, M(gamma gamma), of the two photons near 60 GeV. From a data sample approximately twice as large taken from 1990 to 1992, 6 events are found with M(gamma gamma) distributed between 50 GeV and 72 GeV, while 4.9 events are expected from a QED calculation. There is no evidence for a mass peak; only one event (mu+ mu- gamma gamma) at M(gamma gamma) = 59.4 +/- 0.2 GeV is compatible with the L3 observation. In addition, for M(gamma gamma) > 50 GeV, no event is found for e+e- -> q qbar gamma gamma and only one event is found consistent with e+e- -> nu nubar gamma gamma; this event has M(gamma gamma) = 58.5 +/- 1.9 GeV. High mass photon pair events have also been searched for in gamma gamma collisions. This allows one to set an upper limit of 50 MeV for the width of an assumed resonance decaying to photon pairs.
1993
D., B., I., D., D., D., P., G., C., G., J. P., L., et al. (1993). Search For High-mass Photon Pairs In e+e->f fbar gamma-gamma (f = e, mu,tau, nu, q) At Lep. PHYSICS LETTERS. SECTION B, 308(3-4), 425-434 [10.1016/0370-2693(93)91308-A].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/36530
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