Search for new phenomena using single photon events in the DELPHI detector at LEP

CERN-LEP. DELPHI collaboration. Study of reaction E+ E- --& gt; GAMMA + & apos;nothing& apos; at SQRT(S) = 89.48, 91.26 and 93.08 GeV and search for new phenomena. 21 single photon candidates were observed at SQRT(S) = 89.48 GeV, 148 at SQRT(S) = 91.26 GeV, and 50 at SQRT(S) = 93.08 GeV as a result of visual scan of possible candidates passed all cuts. Then calculated background ( e+ e- gamma ) was subtracted and the corrections for trigger and reconstruction efficiencies were applied to obtained cross sections. The number of light neutrinos coupled to the Z is measured to be N = 2.89 +- 0.38. No evidence was found for anomalous production forenergetic (E & gt; 22 GeV) single photons. Note: the paper was extensively revised from the original preprint to the publication stage. Many of the original numbers have changed. The new data are show in this record.