[en] In this paper, we present methodology for investigating theoretically parity violation in both the elastic and break-up channels of electron--deuteron scattering, restricting ourselves to energies in which non-relativistic expansions are allowed for nucleons. The deficiency in the standard impulse approximation related to gauge invariance is remedied by relating it to the ''elementary particle'' treatment. Results for parity violation in elastic electron--deuteron scattering are presented and discussed

[en] Formulas for angular correlations and capture rates in muon-capture transitions between initial and final nuclear states characterized by spin an isospin [1/2^+-,1/2]/sub ini/ and [1/2^+-,1/2]/sub fin/, and [1⁺,0]/sub tin/ and [0⁺,1]/sub ini/, are derived and applied to μ^-P → ν/sub μ/N, μ^-3He → ν/sub μ/ ³H, and μ^-6Li → ν/sub μ/ ⁶He in a model-independent (elementary-particle) approach. The results indicate that the angular correlations between the momenta of the recoiling final nuclei and the polarizations of the μ^- and/or the initial nuclei are sensitive to the value of the nuclear pseudoscalar form factors F/sub P/(q²). The analysis also indicates that inconsistencies among the available data on μ^-6Li → ν/sub μ/ ⁶He are most likely of experimental origin

[en] It is shown in a model-independent fashion that, even without the conserved vector current test by extracting the shape factors from the observed e^-+ energy spectra in the beta decays of ¹²B and ¹²N, the validity of conservation of vector current and partial conservation of axial vector current and the absence of second-class axial currents have now been individually confirmed by the combination of the muon capture data and the results of the recent asymmetry measurements. On the other hand, it is found that the presence of appreciable meson-exchange corrections does not cause a serious discrepancy between the asymmetry data and the Cohen-Kurath nuclear model after the spin-quadrupole-moment term (from the L = 2 component of the lepton wave functions) and all the theoretical uncertainties are also taken into account

[en] A fairly detailed analysis is given of the available experimental data on ¹²B → ¹²Ce^-anti ν/sub e/, ¹²N → ¹²Ce⁺ν/sub e/, and μ^-12C → ν/sub μ/ ¹²B making use of the ''elementary-particle'' treatment. Our results indicate that the variation with energy of the asymmetry coefficients obtained by Sugimoto et al. cannot be reconciled with the observed value of the muon capture rate on the hypothesis (A) of gross violation of (''strong'') conserved vector current and absence of second-class axial currents and can be reconciled only with great difficulty on the alternative hypothesis (B) of validity of (strong) conserved vector current and presence of relatively large second-class axial currents. On the other hand, a good fit to the observed muon capture rate can be obtained on the hypothesis (C) of (strong) conserved vector current, (''suitably corrected'') partially conserved axial vector current, and absence of second-class axial currents. This last hypothesis leads, of course, to a prediction for the variation with energy of the asymmetry coefficients in contradiction to the results of Sugimoto et al. We also find that the magnitude of the recoil ¹²B polarization obtained by Possoz et al. agrees with that calculated on hypothesis (C) but not with those calculated on hypotheses (A) or

[en] It is shown, in the ''elementary-particle'' treatment, that, if the source to produce the background ¹²B(g.s.) comes only from the cascade processes μ^-12C(g.s.) → ν/sub μ/ ¹²B*(2.62) → ν/sub μ/ ¹²B(g.s.) γ, the average polarization of the recoil ¹²B(g.s.) produced by the direct polarized-muon capture μ^-12C(g.s.) → ν/sub μ/ ¹²B(g.s.) can be extracted reliably from the observed angular distribution of the electrons in the subsequent beta decays of ¹²B(g.s.). Using the recent data of Possoz et al., our result for the average polarization P/sub av/ of the recoil ¹²B(g.s.) from the direct polarized-muon capture is P/sub av/ =0.47 +- 0.05, which agrees very well with the prediction of the standard picture, namely, conservation of vector current, partial conservation of axial vector current, and absence of second-class axial currents

[en] A formalism for investigating the positron-capture reaction e⁺+d→nu-bar/sub e/+p+p at medium positron energy (i.e., 0.5--2.0 GeV) and small p-p excitation energies (i.e., E/sub rel/< or =10 MeV) is described. In view of the small p-p excitation energy E/sub rel/ being considered, we take into account only the ¹S₀ and ³P/sub J/ p-p final states (J = 0, 1, 2). For the polar vector current, an impulse approximation, modified to incorporate current conservation, is employed and additional meson-exchange currents are included in the dominant channel. For the axial vector current, the nucleon-only impulse approximation is used. Numerical results are presented to highlight the prospect of measuring the q² dependence of the nucleon axial form factor f/sub A/(q²). The proposed precision measurement of the nucleon axial form factor may be feasible at the upcoming Continuous Electron Beam Accelerator Facility if the proposed positron ring can actually be constructed

[en] The prospect of using a precision measurement of parity violation in elastic electron-proton scattering in the GeV range to detect manifestations of the nonstandard neutral weak boson Z'⁰ is investigated in some detail. The numerical results indicate that, for an assumed Z'⁰ mass of about 300 GeV, the deviation of the predicted parity-violating beam and target asymmetries from those given by the standard Glashow-Weinberg-Salam electroweak theory can be in the vicinity of several percent. Thus, confirmation of the standard model to within an accuracy of a couple of percent in such measurement should yield a severe constraint on the possible existence of the nonstandard neutral weak boson

[en] A theory of radiative muon capture, with applications to nuclear spin and isospin doublets, is formulated on the basis of the conservation of the hadronic electromagnetic current, the conservation of the hadronic weak polar currents, the partial conservation of the hadronic weak axial-vector current, the SU(2) x SU(2) current algebra for the various hadronic current, and a simplifying dynamical approximation for the hadron-radiating part of the transition amplitude: the ''linearity hypothesis''. The resultant total transition amplitude, which also includes the muon-radiating part, is worked out explicitly and applied to treat the processes μ^-p → ν/sub μ/nγ and μ^-3He → ν/sub μ/ ³Hγ

[en] The possibility of probing parity mixing in ¹⁸F by polarized low-energy inelastic electron scattering is analyzed making use of the ''elementary-particle'' treatment. The nuclear form factors are determined by the γ transition rates, gauge invariance, and certain general features abstracted from nuclear-model calculations. It is found that the effects due to the exchange of the neutral weak boson between the electron and the nucleus are completely negligible as compared with those due to the mixing of the two adjacent nuclear states of opposite parity. It is also found that the enhancement of the asymmetry at backward electron scattering angles rises linearly with the incident electron energy

[en] The theory of radiative muon capture, as formulated in a previous paper on the basis of the conservation of the hadronic electromagnetic current, the conservation of the hadronic weak polar current, the partial conservation of the hadronic weak axial-vector current, the SU(2) x SU(2) current algebra for the various hadronic currents, and the ''linearity hypothesis,'' is applied to the process μ^-12C → ν/sub μ/ ¹²Bγ. The resultant total transition amplitude is worked out explicitly and used to calculate various observable quantities