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 β < ∼ 10, whereas for tan β ≃ 50 heavier slepton mass up to ∼ 1000 GeV can account for the reported 3.2 σ 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 → sγ transition, and find favorable scenarios in the minimal supergravity, gauge-, and mirage-mediation models of supersymmetry breaking.

We estimate the accuracy with which the coefficient of the CP even dimension six operators involving Higgs and two vector bosons (HV V ) can be measured at linear e + e − colliders. Using the optimal observables method for the kinematic distributions, our analysis is based on the five different processes.First is the W W fusion process in the t-channel (e + e − →ν e ν e H), where we use the rapidity y and the transverse momentum p T of the Higgs boson as observables. Second is the ZH pair production process in the s-channel, where we use the scattering angle of the Z and the Z decay angular distributions, reproducing the results of the previous studies. Third is the t-channel ZZ, fusion processes (e + e − → e + e − H), where we use the energy and angular distributions of the tagged e + and e − . In the fourth, we consider the rapidity distribution of the untagged e + e − H events, which can be approximated well as the γγ fusion of the bremsstrahlung photons from e + and e − beams. As the last process, we consider the single tagged e + e − H events, which probe the γe ± → He ± process. All the results are presented in such a way that statistical errors of the constraints on the effective couplings and their correlations are read off when all of them are allowed to vary simultaneously, for each of the above processes, for m H = 120 GeV, at √ s = 250 GeV, 350 GeV 500 GeV and 1 TeV, with and without e − beam polarization of 80%. We find for instance that the HZZ and HW W couplings can be measured with 0.6% and 0.9% accuracy, respectively, for the integrated luminosity of L = 100 fb −1 at √ s = 250 GeV, 350 GeV and L = 500 fb −1 at √ s = 500 GeV, 1 TeV, for the luminosity uncertainty of 1% at each energy. We find that the luminosity uncertainty affects only one combination of the non-standard couplings which are proportional to the standard HW W and HZZ couplings, while it does not affect the errors of the other independent combinations of the couplings. As a consequence, we observe that a few combinations of the eight dimension six operators can be constrained as accurately as the two operators which have been constrained by the precision measurements of the Z and W boson properties.

Abstract.In order to test theoretical frameworks of the baryon-baryon interactions and to confirm the "Pauli effect between quarks" for the first time, we propose an experiment to measure low-energy hyperon proton scattering cross sections in the following channels with high statistics, 1. Σ − p elastic scattering, 2. Σ − p → Λn inelastic scattering, 3. Σ + p elastic scattering. According to theoretical models based on quark-gluon picture for the short range part of the baryon-baryon interactions, the Σ + p channel is expected to have an extremely repulsive core due to the Pauli effect between quarks, which leads a Σ + p cross section twice as large as that predicted by conventional meson exchange models with a phenomenologically treated short range repulsive core. In addition, measurement of the Σ − p channel where the quark Pauli effect is not effective is also necessary to test the present theoretical models based on meson exchange picture with the flavor SU(3) symmetry. Thus this experiment will provide essential data to test the frameworks of the theoretical models of the baryon-baryon interactions and to investigate the nature of the repulsive core which has not been understood yet. In order to overcome the experimental difficulties in measuring low-energy hyperon proton scattering, we will use a new experimental technique in which a liquid H 2 target is used as hyperon production and hyperon scattering targets with a detector system surrounding the LH 2 target for detection of a scattered proton and a decay product from a hyperon. The hyperon scattering event is kinematically identified. Because imaging detectors used in past experiments are not employed, high intensity π beam can be used, allowing us to take high statistics data of 100 times more than the previous experiments. We have proposed an experiment of Σ p scattering at the K1.8 beam line by utilizing the K1.8 beam line spectrometer and the SKS spectrometer. A high intensity π beams of 2×10 7 /spill at 1.32 GeV/c and 1.42 GeV/c for the Σ − and Σ + productions, respectively, are used to produce as many hyperon beam as possible. With 16×10 6 Σ − beam and 55×10 6 Σ + beam around 500 MeV/c which are tagged by the spectrometers, we will detect ∼10,000 Σ − p and Σ + p scattering events and ∼6,000 Σ − p → Λn inelastic reaction events in 60 days beam time in total. In this proceedings, we will present the experimental plan of the scattering experiment and results of the detailed simulation studies.