A search is reported for decays of the Z0 into pi0 gamma eta gamma and eta'(958) gamma in e+e− collisions using data collected during a scan around the Z0 mass. In order to search for pi0 gamma final states, in which the two photons from the pi0 decay are unresolved, the production of pairs of high-energy electromagnetic clusters is studied. The data are compared with the expectations from the pure QED process e+e- -> gamma gamma and a 95% confidence level upper limit on the branching ratio of the Z0 into pi0 gamma of 4.9x 10^-4 is derived. For eta' gamma the decay modes of the mesons that contain two charged particles are largely free from QED background. These modes are used to place upper limits of 4.6x10^-4 and 2.2x10^-4 on the corresponding branching ratios of the Z0.

Search For Decays of the Z0 Into A Photon and A Pseudoscalar Meson

CIOCCI, MARIA AGNESE;BATIGNANI, GIOVANNI;FERRANTE, ISIDORO;FIDECARO, FRANCESCO;FORTI, FRANCESCO;GIORGI, MARCELLO;MESSINEO, ALBERTO MARIA;TONELLI, GUIDO EMILIO;TRIGGIANI, GIUSEPPE;
1990-01-01

Abstract

A search is reported for decays of the Z0 into pi0 gamma eta gamma and eta'(958) gamma in e+e− collisions using data collected during a scan around the Z0 mass. In order to search for pi0 gamma final states, in which the two photons from the pi0 decay are unresolved, the production of pairs of high-energy electromagnetic clusters is studied. The data are compared with the expectations from the pure QED process e+e- -> gamma gamma and a 95% confidence level upper limit on the branching ratio of the Z0 into pi0 gamma of 4.9x 10^-4 is derived. For eta' gamma the decay modes of the mesons that contain two charged particles are largely free from QED background. These modes are used to place upper limits of 4.6x10^-4 and 2.2x10^-4 on the corresponding branching ratios of the Z0.
1990
D., Decamp; B., Deschizeaux; C., Goy; J. P., Lees; M. N., Minard; J. M., Crespo; M., Delfino; E., Fernandez; M., Martinez; R., Miquel; L. M., Mir; S.,...espandi
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/828851
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 10
  • ???jsp.display-item.citation.isi??? 7
social impact