484 research outputs found
Multi-photon corrections to W boson mass determination at hadron colliders
The impact of higher-order final-state photonic corrections on the precise
determination of the W-boson mass at the Tevatron and LHC colliders is
evaluated. The W-mass shift from a fit to the transverse mass distribution is
found to be about 10 MeV in the W --> mu nu channel and a few MeV in the W -->
e nu channel. The calculation, which is implemented in the Monte Carlo event
generator HORACE for data analysis, can contribute to reduce the uncertainty
associated to the W mass measurement at present and future hadron collider
experiments.Comment: 3 pages, 2 figures, to appear in the proceedings of International
Europhysics Conference on High-Energy Physics (EPS 2003), Aachen, Germany,
17-23 Jul 200
A new approach to evaluate the leading hadronic corrections to the muon g-2
We propose a novel approach to determine the leading hadronic corrections to
the muon g-2. It consists in a measurement of the effective electromagnetic
coupling in the space-like region extracted from Bhabha scattering data. We
argue that this new method may become feasible at flavor factories, resulting
in an alternative determination potentially competitive with the accuracy of
the present results obtained with the dispersive approach via time-like data.Comment: 7 pages, 3 figures. Version accepted for publication in Phys. Lett.
Status and accuracy of the Monte Carlo generators for luminosity measurements
The status and accuracy of the precision Monte Carlo generators used for
luminosity measurements at flavour factories is reviewed. It is shown that,
thanks to a considerable, long-term effort in tuned comparisons between the
predictions of independent programs, as well as in the validation of the
generators against the presently available calculations of the
next-to-next-to-leading order QED corrections to Bhabha scattering, the
theoretical accuracy reached by the most precise tools is of about one per
mille. This error estimate is valid for realistic experimental cuts, appears to
be quite robust and is already sufficient for very accurate luminosity
measurements. However, recent progress and possible advances to further improve
it are also discussed.Comment: 6 pages, 1 table. Proceedings of the PhiPsi09 workshop, Oct. 13-16,
2009, Beijing, Chin
Full one-loop electroweak corrections to e+e- to 3 jets at linear colliders
We describe the impact of the full one-loop electroweak terms of O(alpha_s
alpha_EM^3) entering the electron-positron into three-jet cross-section from
sqrt(s)=M_Z to TeV scale energies. We include both factorisable and
non-factorisable virtual corrections and photon bremsstrahlung. Their
importance for the measurement of alpha_S from jet rates and shape variables is
explained qualitatively and illustrated quantitatively, also in presence of
b-tagging.Comment: 6 pages, to appear in the proceedings of the workshop "LC09 -- e+e-
Physics at the TeV scale and the Dark Matter Connection", 21-24 September
2009, Perugia (Italy). Minor corrections, references added
- …