Observation of a soft photon signal in excess of QED expectations in pp interactions

Authors :: Belogianni, A. Beusch, W. Brodbeck, T.J. Dzheparov, F.S. French, B.R. Ganoti, P. Kinson, J.B. Kirk, A. Lenti, V. Minashvili, I. Perepelitsa, V.F. Russakovich, N. Singovsky, A.V. Sonderegger, P. Spyropoulou-Stassinaki, M. Baillie, O.V.
Publication Year :: 2002
Abstract: Photons produced in pp interactions at 450 GeV/c were detected by reconstructing the e+e- pairs of photon conversions in a 1 mm thick lead sheet placed in front of the MWPCs of the OMEGA spectrometer at CERN. A soft photon signal 4.1 ± 0.8 times the inner bremsstrahlung prediction was observed in the forward rapidity region (Yc.m.s. ≥ 1.2), thus extending the domain of the anomalous soft photon effect seen already in K+p, π+p and π-p interactions. © 2002 Elsevier Science B.V. All rights reserved.

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