10,764 research outputs found

    Precision Measurement of sin^2 theta_W at a Reactor

    Full text link
    This paper presents a strategy for measuring sin^2 theta_W to ~1% at a reactor-based experiment, using antineutrinos electron elastic scattering. This error is comparable to the NuTeV, SLAC E158, and APV results on sin^2 theta_W, but with substantially different contributions to the systematics. An improved method for identifying antineutrino proton events, which serve both as a background and as a normalization sample, is described. The measurement can be performed using the near detector of the presently proposed reactor-based oscillation experiments. We conclude that an absolute error of delta(sin^2 theta_W)=0.0019 may be achieved.Comment: To be Submitted to Phys. Rev.

    Using Reactors to Measure θ13\theta_{13}

    Full text link
    A next-generation neutrino oscillation experiment using reactor neutrinos could give important information on the size of mixing angle θ13\theta_{13}. The motivation and goals for a new reactor measurement are discussed in the context of other measurements using off-axis accelerator neutrino beams. The reactor measurements give a clean measure of the mixing angle without ambiguities associated with the size of the other mixing angles, matter effects, and effects due to CP violation. The key question is whether a next-generation experiment can reach the needed sensitivity goals to make a measurement for sin22θ13\sin^{2}2\theta_{13} at the 0.01 level. The limiting factors associated with a reactor disappearance measurement are described with some ideas of how sensitivities can be improved. Examples of possible experimental setups are presented and compared with respect to cost and sensitivity

    A strong ν¨ν˙\ddot{\nu} - \dot{\nu} correlation in radio pulsars with implications for torque variations

    Full text link
    We present an analysis of the spin-down parameters for 131 radio pulsars for which ν¨\ddot\nu has been well determined. These pulsars have characteristic ages ranging from 10310810^{3} - 10^{8} yr and spin periods in the range 0.4--30 s; nearly equal numbers of pulsars have ν¨>0\ddot\nu>0 as ν¨<0\ddot\nu<0. We find a strong correlation of ν¨\ddot\nu with ν˙\dot{\nu}, {\em independent of the sign of} ν¨\ddot\nu. We suggest that this trend can be accounted for by small, stochastic deviations in the spin-down torque that are directly proportional (in magnitude) to the spin-down torque.Comment: MNRAS, 4 pages, 2 figures. Minor editorial changes and typos correcte

    Differential thresholds for motions in the periphery

    Get PDF
    Differential thresholds for rotary and linear motion in the peripher

    Pentaquark searches at FOCUS

    Full text link
    We find no evidence for high-energy photoproduction of pentaquarks at 1540 MeV/c2c^2, 1862 MeV/c2c^2, or 3099 MeV/c2c^2 using decay modes pKS0pK_S^0, Ξπ\Xi^-\pi^-, and D()pD^{(*)-}p, respectively.Comment: Proceedings from talk at 2004 DPF Meeting at University of California, Riversid