W ANOMALOUS MOMENTS AND THE POLARIZATION ASYMMETRY ZERO IN GAMMA-E-]W-NU

Citation
Sj. Brodsky et al., W ANOMALOUS MOMENTS AND THE POLARIZATION ASYMMETRY ZERO IN GAMMA-E-]W-NU, Physical review. D. Particles and fields, 52(9), 1995, pp. 4929-4935
Citations number
52
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics, Particles & Fields
ISSN journal
0556-2821
Volume
52
Issue
9
Year of publication
1995
Pages
4929 - 4935
Database
ISI
SICI code
0556-2821(1995)52:9<4929:WAMATP>2.0.ZU;2-3
Abstract
We show from general principles that there must be a center-of-mass en ergy root s(0) where the polarization asymmetry A = Delta sigma(gamma e --> Wv)/sigma(gamma e --> Wv) for circularly polarized photon and el ectron beams vanishes. In the case of the standard model, the crossing point where the asymmetry changes sign occurs in Born approximation a t root s(gamma e) = 3.1583 ... Mw similar or equal to 254 GeV. We demo nstrate the sensitivity of the position of the polarization asymmetry zero to modification of the SM trilinear gamma WW coupling. Given reas onable assumptions for the luminosity and energy range for the Next Li near Collider with a backscattered laser beam, we show that the zero p oint, root s(0), of the polarization asymmetry may be determined with sufficient precision to constrain the anomalous couplings of the W to better than the 1% level at 95% C.L. In addition to the fact that only a limited range of energy is required, the polarization asymmetry mea surements have the important advantage that many of the systematic err ors cancel in taking cross section ratios. The position of the zero th us provides an additional weapon in the arsenal used to probe anomalou s trilinear gauge couplings.