The production of final 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 pb(-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 final states new limits are placed on the parameters of models involving e(+)e(-)gamma gamma contact interactions and excited electrons. The 95% confidence level lower limits on the QED cut-off parameters Lambda(+) and Lambda(-) are found to be 169 and 132 GeV respectively.
A study of single and multi-photon production in e(+)e(-) collisions at centre-of-mass energies of 130 and 136 GeV
SELVAGGI, Giovanna;NUZZO, Salvatore Vitale;DE PALMA, Mauro
1996-01-01
Abstract
The production of final 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 pb(-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 final states new limits are placed on the parameters of models involving e(+)e(-)gamma gamma contact interactions and excited electrons. The 95% confidence level lower limits on the QED cut-off parameters Lambda(+) and Lambda(-) are found to be 169 and 132 GeV respectively.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.