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A study of photon production in hadronic events from e+ e- annihilation

Research output: Contribution to journalJournal article


<mark>Journal publication date</mark>1990
<mark>Journal</mark>Zeitschrift für Physik C Particles and Fields
Issue number1
Number of pages7
Pages (from-to)1-7
<mark>Original language</mark>English


Results are presented on an investigation of photons produced in multihadronic final states frome + e − annihilation at 35 GeV and 44 GeV center of mass energies. Scalling violation between 14 and 44 GeV is observed in inclusive photon spectra. Comparing inclusive π0 spectra with charged pion spectra it is found that the average π0 multiplicity exceeds the charged pion multiplicity scaled by factor of 0.5 by (16±5)% and (21±7)% at 35 and 44 GeV respectively. The excess can be attributed to isospin violating decays of hadrons. The η multiplicity is found to be 〈n η〈=0.64±0.09±0.06 at 35 GeV. With a significance of three standard deviations a signal from quark bremsstrahlung is observed. The measured charge asymmetry in hadronic final states, due to the interference between initial and final state radiation, ofA=−0.141±0.041 is in accord with QED expectations. An interference effect in the azimuth angle distribution of charged jets around the photon direction is observed for the first time.