6 research outputs found

    Measurement of the Proton Asymmetry Parameter C in Neutron Beta Decay

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    The proton asymmetry parameter C in neutron decay describes the correlation between neutron spin and proton momentum. In this Letter, the first measurement of this quantity is presented. The result C=-0.2377(26) agrees with the Standard Model expectation. The coefficient C provides an additional parameter for new and improved Standard Model tests. From a differential analysis of the same data (assuming the Standard Model), we obtain lambda=-1.275(16) as ratio of axial-vector and vector coupling constant.Comment: 4 pages, 2 figure

    gamma gamma angular-correlation analysis of Hg-200 after cold-neutron capture

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    We report on a gamma gamma angular-correlation experiment investigating Hg-200 after cold-neutron capture. The experiment was performed using eight high-purity germanium detectors mounted on an array installed at the PF1B neutron beam line of the research reactor of the Institut Laue-Langevin in Grenoble, France. The geometry of the array allows gamma gamma angular-correlation analyses that can be used for the determination of level spins and multipole mixing ratios in Hg-200. We present multipole mixing ratios for secondary gamma rays and investigate the nature of the Hg-200 neutron-capture state by analyzing the observed primary gamma rays of this nucleus

    Precise measurement of energies in Sn-115 following the (n,gamma) reaction

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    The first measurement of. rays from the Sn-114(n,gamma) reaction using cold neutrons, performed with an array of Ge detectors at the PF1B facility of the Institute Laue-Langevin in Grenoble, has provided the most accurate energy, Q(beta) = 173(12) eV, of beta(-) decay of the In-115 ground state to the first excited state in Sn-115. This is the lowest of all such energies in the known nuclear landscape. The accuracy of the neutron binding energy of Sn-115 and the mass of Sn-114 have been improved
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