Radiative Corrections to Fixed Target Moller Scattering Including Hard Bremsstrahlung Effects

We present a calculation of the complete $O(\alpha)$ electroweak radiative corrections to the Moller scattering process e^-e^- -> e^-e^-, including hard bremsstrahlung contributions. We study the effects of these corrections on both the total cross section and polarization asymmetry measured in low energy fixed target experiments. Numerical results are presented for the experimental cuts relevant for E-158, a fixed target e^-e^- experiment being performed at SLAC; the effect of hard bremsstrahlung is to shift the measured polarization asymmetry by approximately +4%. We briefly discuss the remaining theoretical uncertainty in the prediction for the low energy Moller scattering polarization asymmetry.Comment: 22 pgs; minor clarifications added and typos fixe

Supercurrents through gated superconductor-normal-metal-superconductor contacts: the Josephson-transistor

We analyze the transport through a narrow ballistic superconductor-normal- metal-superconductor Josephson contact with non-ideal transmission at the superconductor-normal-metal interfaces, e.g., due to insulating layers, effective mass steps, or band misfits (SIN interfaces). The electronic spectrum in the normal wire is determined through the combination of Andreev- and normal reflection at the SIN interfaces. Strong normal scattering at the SIN interfaces introduces electron- and hole-like resonances in the normal region which show up in the quasi-particle spectrum. These resonances have strong implications for the critical supercurrent $I_c$ which we find to be determined by the lowest quasi-particle level: tuning the potential $\mu_{x0}$ to the points where electron- and hole-like resonances cross, we find sharp peaks in $I_{\rm c}$, resulting in a transitor effect. We compare the performance of this Resonant Josephson-Transistor (RJT) with that of a Superconducting Single Electron Transistor (SSET).Comment: to appear in PRB, 11 pages, 9 figure

QED Radiative Corrections in Processes of Exclusive Pion Electroproduction

Formalism for radiative correction (RC) calculation in exclusive pion electroproduction on the proton is presented. A FORTRAN code EXCLURAD is developed for the RC procedure. The numerical analysis is done in the kinematics of current Jefferson Lab experiments.Comment: 13 pages, 9 figures; requires RevTeX