5 research outputs found
The Effective Weak Mixing Angle in the MSSM
The predictions of the MSSM are discussed in the light of recent LEP and SLD
precision data. The full supersymmetric one loop corrections to the effective
weak mixing angle, experimentally determined in LEP and SLD experiments, are
considered. It is demonstrated, both analytically and numerically, that,
potentially dangerous, large logarithmic sparticle corrections are cancelled.
The relative difference factor \Delta k between the mixing angle defined as a
ratio of couplings and the experimentally obtained angle is discussed. It is
found that \Delta k is dominated by the oblique corrections, while the
non-oblique overall supersymmetric EW and SQCD corrections are negligible. The
comparison of the MSSM with radiative electroweak symmetry breaking to the
LEP+SLD precision data indicates that rather large values of the soft breaking
parameter M_{1/2} in the region greater than 500 GeV are preferred.Comment: 36 pages, 9 figures, references adde
Search for excited taus from Z\u3csup\u3e0\u3c/sup\u3e decays
\u3cp\u3eWe have searched for excited taus from Z\u3csup\u3e0\u3c/sup\u3e decay in the channels e\u3csup\u3e+\u3c/sup\u3ee\u3csup\u3e-\u3c/sup\u3e → τ\u3csup\u3e*+\u3c/sup\u3eτ\u3csup\u3e*-\u3c/sup\u3e → τ\u3csup\u3e+\u3c/sup\u3eτ\u3csup\u3e-\u3c/sup\u3eγ γ and e\u3csup\u3e+\u3c/sup\u3ee\u3csup\u3e-\u3c/sup\u3e → ττ\u3csup\u3e*\u3c/sup\u3e → τ\u3csup\u3e+\u3c/sup\u3eτ\u3csup\u3e-\u3c/sup\u3eγ, using the L3 detector at LEP. Using the τ\u3csup\u3e*\u3c/sup\u3e pair production channel, we can exclude a τ\u3csup\u3e*\u3c/sup\u3e up to a mass of 45.5 geV at 95% confidence level. We have also determined upper limits on the ττ\u3csup\u3e*\u3c/sup\u3eZ\u3csup\u3e0\u3c/sup\u3e and ττ\u3csup\u3e*\u3c/sup\u3eγ couplings as a function of m\u3csub\u3eτ*\u3c/sub\u3e up to 89.3 GeV.\u3c/p\u3