The electroweak form factor \hat{\kappa}(q^2) and the running of \sin^2 \hat{\theta}_W
Abstract
Gauge independent form factors \rho^(e; e) and \hat{\kappa}^(e; e)(q^2) for Moller scattering at s << m_W^2 are derived. It is pointed out that \hat{\kappa}^(e; e) is very different from its counterparts in other processes. The relation between the effective parameter \hat{\kappa}^(e; e)(q^2,\mu) \sin^2 \hat{\theta}_W(\mu) and \sin^2 \theta_eff is derived in a scale-independent manner. A gauge and process-independent running parameter \sin^2 \hat{\theta}_W (q^2), based on the pinch-technique self-energy a_{\gamma Z} (q^2), is discussed for all q^2 values. At q^2=0 it absorbs very accurately the Czarnecki-Marciano calculation of the Moller scattering asymmetry at low s values, and at q^2 = m^2_Z it is rather close to \sin^2 \theta_eff. The q^2 dependence of \sin^2 \hat{\theta}_W (q^2) is displayed in the space and time-like domains.
Keywords
Cite
@article{arxiv.hep-ph/0307200,
title = {The electroweak form factor \hat{\kappa}(q^2) and the running of \sin^2 \hat{\theta}_W},
author = {A. Ferroglia and G. Ossola and A. Sirlin},
journal= {arXiv preprint arXiv:hep-ph/0307200},
year = {2009}
}
Comments
A new paragraph has been inserted at the beginning of the discussion in Section 4