11 research outputs found
Photonic SUSY Two-Loop Corrections to the Muon Magnetic Moment
Photonic SUSY two-loop corrections to the muon magnetic moment are
contributions from diagrams where an additional photon loop is attached to a
SUSY one-loop diagram. These photonic corrections are evaluated exactly,
extending a leading-log calculation by Degrassi and Giudice. Compact analytical
expressions are provided and the numerical behaviour is discussed. The photonic
corrections reduce the SUSY one-loop result by 7...9%. The new terms are
typically around ten times smaller than the leading logarithms, but they can be
larger and have either sign in cases with large SUSY mass splittings. We also
provide details on renormalization and regularization and on how to incorporate
the photonic corrections into a full SUSY two-loop calculation.Comment: 25 page
The MSSM confronts the precision electroweak data and the muon g-2
We update the electroweak study of the predictions of the Minimal
Supersymmetric Standard Model (MSSM) including the recent results on the muon
anomalous magnetic moment, the weak boson masses, and the final precision data
on the Z boson parameters from LEP and SLC. We find that the region of the
parameter space where the slepton masses are a few hundred GeV is favored from
the muon g-2 for \tan\beta \ltsim 10, whereas for \tan\beta \simeq 50 heavier
slepton mass up to \sim 1000 GeV can account for the reported 3.2 \sigma
difference between its experimental value and the Standard Model (SM)
prediction. As for the electroweak measurements, the SM gives a good
description, and the sfermions lighter than 200 GeV tend to make the fit worse.
We find, however, that sleptons as light as 100 to 200 GeV are favored also
from the electroweak data, if we leave out the jet asymmetry data that do not
agree with the leptonic asymmetry data. We extend the survey of the preferred
MSSM parameters by including the constraints from the b \to s \gamma
transition, and find favorable scenarios in the minimal supergravity, gauge-,
and mirage-mediation models of supersymmetry breaking.Comment: 40 pages, 12 figures. v2: minor changes, references added, version to
appear in JHE