2,179 research outputs found
Precision Electroweak Parameters and the Higgs Mass
The status of various precisely measured electroweak parameters is reviewed.
Natural relations among them are shown to constrain the Higgs mass, m_H, via
quantum loop effects to relatively low values. A comparison with direct Higgs
searches is made.Comment: To be published in the Proceedings of MuMu99-5th International
Conference on Physics Potential and Development of Muon Colliders, San
Francisco, CA, Dec. (1999). 12 pages, Late
Electroweak Radiative Corrections To Polarized M{\o}ller Scattering Asymmetries
One loop electroweak radiative corrections to left-right parity violating
M{\o}ller scattering () asymmetries are presented. They
reduce the standard model (tree level) prediction by 40 \% where the
main shift and uncertainty stem from hadronic vacuum polarization loops. A
similar reduction also occurs for the electron-electron atomic parity violating
interaction. That effect can be attributed to an increase of
by in running from to 0. The
sensitivity of the asymmetry to ``new physics'' is also discussed.Comment: 14 pages, Revtex, postscript file including figures is available at
ftp://ttpux2.physik.uni-karlsruhe.de/ttp95-14/ttp95-14.ps or via WWW at
http://ttpux2.physik.uni-karlsruhe.de/cgi-bin/preprints/ (129.13.102.139
Improved Calculation of Electroweak Radiative Corrections and the Value of V_ud
A new method for computing hadronic effects on electroweak radiative
corrections to low-energy weak interaction semileptonic processes is described.
It employs high order perturbative QCD results originally derived for the
Bjorken sum rule along with a large N QCD-motivated interpolating function that
matches long and short-distance loop contributions. Applying this approach to
the extraction of the CKM matrix element V_ud from superallowed nuclear beta
decays reduces the theoretical loop uncertainty by about a factor of 2 and
gives V_ud = 0.97377(11)(15)(19). Implications for CKM unitarity are briefly
discussed.Comment: 12 pages, no figures. Ref. [8] correcte
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