Weak Interaction Studies with 6He

The 6He nucleus is an ideal candidate to study the weak interaction. To this end we have built a high-intensity source of 6He delivering ~10^10 atoms/s to experiments. Taking full advantage of that available intensity we have performed a high-precision measurement of the 6He half-life that directly probes the axial part of the nuclear Hamiltonian. Currently, we are preparing a measurement of the beta-neutrino angular correlation in 6He beta decay that will allow to search for new physics beyond the Standard Model in the form of tensor currents.Comment: 5 pages, 4 figures, proceedings for the Eleventh Conference on the Intersections of Particle and Nuclear Physics (CIPANP 2012

Effects of T- and P-odd weak nucleon interaction in nuclei: renormalizations due to residual strong interaction, matrix elements between compound states and their correlations with P-violating matrix elements

Manifestations of P-,T-odd weak interaction between nucleons in nucleus are considered. Renormalization of this interaction due to residual strong interaction is studied. Mean squared matrix elements of P-,T-odd weak interaction between compound states are calculated. Correlators between P-,T-odd and P-odd, T-even weak interaction matrix elements between compound states are considered and estimates for these quantities are obtained.Comment: Submitted to Phys. Rev. C; 21 pages, REVTEX 3, no figure

Weak Interaction Contributions in Light Muonic Atoms

Weak interaction contributions to hyperfine splitting and Lamb shift in light electronic and muonic atoms are calculated. We notice that correction to hyperfine splitting turns into zero for deuterium. Weak correction to the Lamb shift in hydrogen is additionally suppressed in comparison with other cases by a small factor $(1-4\sin^2\theta_W)$.Comment: Minor editorial corrections, reference added, version to be published in Phys. Rev.

Pion, muon decays and weak interaction symmetries

We review the recent measurements of the rare pion decays: Pi+ -> Pi0 e+ Nu [pion beta, Pi_(e3), or Pi_beta decay], radiative decay Pi+ -> e+ Nu Gamma [Pi_(e2Gamma) or RPD], and Pi+ -> e+ Nu [Pi_(e2)] decay, as well as the radiative muon decay, Mu -> e Nu Nu-bar Gamma, their theoretical implications, and prospects for further improvement.Comment: 4 pages, 2 figures; talk presented at the Fourth International Symposium on Symmetries in Subatomic Physics (SSP 2009), held at the National Taiwan University, Taipei, Taiwan, 2-5 June 2009; to appear in "Symmetries in Subatomic Physics", P. Hwang, ed., North Holland

Low Energy Tests of the Weak Interaction

The study of low energy weak interactions of light quarks and leptons continues to provide important insights into both the Standard Model as well as the physics that may lie beyond it. We review the status and future prospects for low energy electroweak physics. Recent important experimental and theoretical developments are discussed and open theoretical issues are highlighted. Particular attention is paid to neutrino physics, searches for permanent electric dipole moments, neutral current tests of the running of the weak mixing angle, weak decays, and muon physics. We argue that the broad range of such studies provides an important complement to high energy collider searches for physics beyond the Standard Model. The use of low energy weak interactions to probe novel aspects of hadron structure is also discussed.Comment: 82 pages, 6 figures: published version (with some additional references and a typographical error fixed

Induced pseudoscalar coupling of the proton weak interaction

The induced pseudoscalar coupling $g_p$ is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test of quantum chromodynamics at low energies. During the past decade a large body of new data relevant to the coupling $g_p$ has been accumulated. This data includes measurements of radiative and non radiative muon capture on targets ranging from hydrogen and few--nucleon systems to complex nuclei. Herein the authors review the theoretical underpinnings of $g_p$, the experimental studies of $g_p$, and the procedures and uncertainties in extracting the coupling from data. Current puzzles are highlighted and future opportunities are discussed.Comment: 58 pages, Latex, Revtex4, prepared for Reviews of Modern Physic

Two interacting particles in a disordered chain II: Critical statistics and maximum mixing of the one body states

For two particles in a disordered chain of length $L$ with on-site interaction $U$, a duality transformation maps the behavior at weak interaction onto the behavior at strong interaction. Around the fixed point of this transformation, the interaction yields a maximum mixing of the one body states. When $L \approx L_1$ (the one particle localization length), this mixing results in weak chaos accompanied by multifractal wave functions and critical spectral statistics, as in the one particle problem at the mobility edge or in certain pseudo-integrable billiards. In one dimension, a local interaction can only yield this weak chaos but can never drive the two particle system to full chaos with Wigner-Dyson statistics.Comment: Second paper of a serie of four, to appear in Eur. Phys.