|
Title
|
|
|
|
Measurement of the cross-section at LEP energies
|
|
|
Author
|
|
|
|
|
|
|
Abstract
|
|
|
|
| The total and the differential cross sections for the reaction e+e- --> gammagamma(gamma) have been measured with the DELPHI detector at LEP using an integrated luminosity of 36.9 pb-1. The results agree with the QED predictions and consequently there is no evidence for non-standard channels with the same experimental signature. The lower limits obtained on the QED cutoff parameters are LAMBDA+ > 143 GeV and LAMBDA- > 120 GeV, and the lower bound on the mass of an excited electron with an effective coupling constant lambda(gamma) = 1 is 132 GeV/c2. Upper limits on the branching ratios for the decays Z0 --> gammagamma, Z0 --> pi0gamma, Z0 --> etagamma and Z0 --> gammagammagamma have been determined to be 5.5 x 10(-5), 5.5 x 10(-5), 8.0 x 10(-5), and 1.7 x 10-5 respectively. All the limits are at the 95% confidence level. |
|
|
|
Language
|
|
|
|
English
|
|
|
Source (journal)
|
|
|
|
Physics letters : B. - Amsterdam, 1967, currens
|
|
|
Publication
|
|
|
|
Amsterdam
:
North-Holland
,
1994
|
|
|
ISSN
|
|
|
|
0370-2693
|
|
|
DOI
|
|
|
|
10.1016/0370-2693(94)90745-5
|
|
|
Volume/pages
|
|
|
|
327
:3-4
(1994)
, p. 386-396
|
|
|
ISI
|
|
|
|
A1994NP23100032
|
|
|
Full text (Publisher's DOI)
|
|
|
|
|
|
|
Full text (publisher's version - intranet only)
|
|
|
|
|
|