### Abstract

Differential cross sections for e^{+}e^{-}→γγ have been measured at center-of-mass energies of 55, 56, 56.5 and 57 GeV. The results are in good agreement with those predicted by QED. Possible deviations from QED are studied in terms of contact interactions, and the limits on compositeness scales are obtained. Using events with a gramma pair in the final state, a search is made for the pair production of unstable photons, {Mathematical expression}. No candidate events were found and a new limit on the photino mass is obtained.

Original language | English |
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Pages (from-to) | 175-191 |

Number of pages | 17 |

Journal | Zeitschrift für Physik C Particles and Fields |

Volume | 45 |

Issue number | 2 |

DOIs | |

Publication status | Published - Jun 1989 |

Externally published | Yes |

### ASJC Scopus subject areas

- Physics and Astronomy (miscellaneous)

## Fingerprint Dive into the research topics of 'Measurement of the differential cross sections of e<sup>+</sup>e<sup>-</sup>→γγ and e<sup>+</sup>e<sup>-</sup>→γγγ at {Mathematical expression} and 57 GeV and search for unstable photino pair production'. Together they form a unique fingerprint.

## Cite this

^{+}e

^{-}→γγ and e

^{+}e

^{-}→γγγ at {Mathematical expression} and 57 GeV and search for unstable photino pair production.

*Zeitschrift für Physik C Particles and Fields*,

*45*(2), 175-191. https://doi.org/10.1007/BF01674449