We report the first observation of Z/γ* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e-→ e+e-Z/γ*, where one of the final state electrons is undetected. Approximately 55pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/γ* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/γ* branching ratio to hadrons to be (0.9 ± 0.3 ± 0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)eγ* production, this product is found to be (4.1 ± 1.6 ± 0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.
|Number of pages||14|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|State||Published - 22 Oct 1998|
ASJC Scopus subject areas
- Nuclear and High Energy Physics