Precision Electroweak Parameters and the Higgs Mass

The status of various precisely measured electroweak parameters is reviewed. Natural relations among them are shown to constrain the Higgs mass, m_H, via quantum loop effects to relatively low values. A comparison with direct Higgs searches is made.Comment: To be published in the Proceedings of MuMu99-5th International Conference on Physics Potential and Development of Muon Colliders, San Francisco, CA, Dec. (1999). 12 pages, Late

Intense Neutrino Beams and Leptonic CP Violation

Effects of the Leptonic CP violating phase,\delta, on 3 generation neutrino oscillation rates and asymmetries are discussed. A figure of merit argument is used to show that our ability to measure the phase \delta is rather insensitive to the value of \theta_{13} (for \sin^22\theta_{13}\gsim0.01) as well as the detector distance (for very long oscillation baselines). Using a study of \nu_\mu\to\nu_e oscillations for BNL-Homestake (2540 km) we show that a conventional horn focused wide band neutrino beam generated by an intense 1-2 MW proton source combined with a very large water Cherenkov detector (250-500 kton) should be able to determine \delta to about \pm 15^\circ$in 5\times 10^7sec of running. In addition, such an effort would also measure the other oscillation parameters (\theta_{ij},\Delta m^2_{ij}) with high precision. Similar findings apply to a Fermilab-Homestake (1280 km)baseline. We also briefly discuss features of Superbeams, Neutrino Factories and Beta-Beams.Comment: 7 pages,$ Figures, to be published in Neutrino2006 Proceeding

Improved Calculation of Electroweak Radiative Corrections and the Value of V_ud

A new method for computing hadronic effects on electroweak radiative corrections to low-energy weak interaction semileptonic processes is described. It employs high order perturbative QCD results originally derived for the Bjorken sum rule along with a large N QCD-motivated interpolating function that matches long and short-distance loop contributions. Applying this approach to the extraction of the CKM matrix element V_ud from superallowed nuclear beta decays reduces the theoretical loop uncertainty by about a factor of 2 and gives V_ud = 0.97377(11)(15)(19). Implications for CKM unitarity are briefly discussed.Comment: 12 pages, no figures. Ref. [8] correcte