We report on measurements of low-mass electron pairs in 450 GeV p-Be, p-Au, and 200 GeV/nucleon S-Au collisions at central rapidities. For the proton induced interactions, the low-mass spectra are, within the systematic errors, satisfactorily explained by electron pairs from hadron decays, whereas in the S-Au system an enhancement over the hadronic contributions by a factor of 5.0+/-0.7\(stat\)+/-2.0\(syst\) in the invariant mass range 0.2<m<1.5 GeV/c2 is observed. The properties of the excess suggest that it arises from two-pion annihilation ππ-->e+e-.

Enhanced Production of Low-Mass Electron Pairs in 200 GeV/Nucleon S-Au Collisions at the CERN-Super Proton Synchrotron

GATTI, EMILIO;SAMPIETRO, MARCO;
1995-01-01

Abstract

We report on measurements of low-mass electron pairs in 450 GeV p-Be, p-Au, and 200 GeV/nucleon S-Au collisions at central rapidities. For the proton induced interactions, the low-mass spectra are, within the systematic errors, satisfactorily explained by electron pairs from hadron decays, whereas in the S-Au system an enhancement over the hadronic contributions by a factor of 5.0+/-0.7\(stat\)+/-2.0\(syst\) in the invariant mass range 0.2e+e-.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/665929
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