A study of single and multi-photon production in e+e− collisions at centre-of-mass energies of 130 and 136 GeV

D. Buskulic, I. De Bonis, D. Decamp, P. Ghez, C. Goy, J.-P. Lees, A. Lucotte, M.-N. Minard, P. Odier, B. Pietrzyk, M.P. Casado, M. Chmeissani (+380 others)
1996 Physics Letters B  
The production of nal states involving one or more energetic photons from e + e collisions at high energies is studied using data collected by the ALEPH detector at LEP. The data consist of two samples of 2:9 p b 1 each, recorded at centre-of-mass energies of 130 GeV and 136 GeV. The data are in agreement with the predictions of the Standard Model. From an analysis of two-photon nal states new limits are placed on the parameters of models involving e + e contact interactions and excited
more » ... and excited electrons. The 95% condence level lower limits on the QED cut-o parameters + and are found to be 169 and 132 GeV respectively.
doi:10.1016/0370-2693(96)00930-6 fatcat:7tznybe5kra3rilqwebydanywm