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

Performance of the EM end-cap presampler in the 1999 testbeam run

Two electromagnetic end-cap presampler modules were tested together with the EM end-cap calorimeter Module 0 on H6 SPS electron beam at CERN in September-October 1999. The results on energy resolution for electrons with energy in the range 20-100 GeV and various amounts of upstream dead material are presented. They are found in agreement with simulation. It is shown that using of the presampler allows one to account for the energy loss in upstream material and thus considerably recover the degradation of the energy resolution. The results of noise and crosstalk calculation and measurement in calibration as well as in data runs are also reported