Search

Abstract: A measurement of the neutrino asymmetry is presented which represents the first search for new physics using polarized radioactive atoms initially cooled and confined in a magneto-optical trap. Optical pumping and photoionization techniques are used to generate and measure, in situ, a highly spin-polarized sample of the short-lived -emitter 37K. The angular distribution of neutrinos from this polarized decay, inferred from the daughter recoil asymmetry, is used to search for a hypothetical current in the weak interaction. We find the ν asymmetry parameter to be , in agreement with the standard model''s purely interaction. [Copyright &y& Elsevier]

Abstract: The electric-quadrupole coupling constant of the ground states of the proton drip line nucleus 20Na (, ) and the neutron-deficient nucleus 21Na (, ) in a hexagonal ZnO single crystal were precisely measured to be and , respectively, using the multi-frequency β-ray detecting nuclear magnetic resonance technique under presence of an electric-quadrupole interaction. An electric-quadrupole coupling constant of 27Na in the ZnO crystal was also measured to be . The electric-quadrupole moments were extracted as and , using the electric-coupling constant of 27Na and the known quadrupole moment of this nucleus as references. The present results are well explained by shell-model calculations in the full sd-shell model space. [Copyright &y& Elsevier]