1,632 research outputs found
Radiative Corrections and the Universality of the Weak Interactions
We review the radiative corrections to superallowed Fermi transitions and
neutron beta decay in the Standard Model, and their relevance for the
universality of the Weak Interactions.Comment: 5 pages. Invited talk at 8th Conference on the Intersections of
Particle and Nuclear Physics (CIPANP 2003), New York, New York, 19-24 May
200
Topics in Electroweak Physics
We briefly discuss five topics in Precision Electroweak Physics: i) the
recently proposed Effective Scheme of Renormalization, ii) evidence for
electroweak bosonic corrections derived from the radiative correction
Delta_r_eff, iii) an approach to estimate the scale of new physics in a
hypothetical Higgs-less scenario, iv) simple and accurate formulae for s^2_eff,
M_W, Gamma_l, and their physical applications, v) a recent proposal concerning
the field renormalization constant for unstable particles.Comment: 5 pages, talk presented at the International Symposium Radcor 2002,
September 8-13, Kloster Banz, German
The electroweak form factor \hat{\kappa}(q^2) and the running of \sin^2 \hat{\theta}_W
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.Comment: A new paragraph has been inserted at the beginning of the discussion
in Section
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