Matthew Redshaw

Masses of Te-130 and Xe-130 and Double-beta-Decay Q Value of Te-130

The atomic masses of 130Te and 130Xe have been obtained by measuring cyclotron frequency ratios of pairs of triply charged ions simultaneously trapped in a Penning trap. The results, with 1 standard deviation uncertainty, are M(130Te)=129.906 222 744(16) u and M(130Xe)=129.903 509 351(15) u. From the mass difference the double-beta-decay Q value of 130Te is determined to be Qbetabeta(130Te)=2527.518(13) keV. This is a factor of 150 more precise than the result of the AME2003 [G. Audi, Nucl. Phys. A729, 337 (2003)10.1016/j.nuclphysa.2003.11.003].

Masses ofTe130andXe130and Double-β-DecayQValue ofTe130

The atomic masses of 130Te and 130Xe have been obtained by measuring cyclotron frequency ratios of pairs of triply charged ions simultaneously trapped in a Penning trap. The results, with 1 standard deviation uncertainty, are M(130Te)=129.906 222 744(16) u and M(130Xe)=129.903 509 351(15) u. From the mass difference the double-beta-decay Q value of 130Te is determined to be Qbetabeta(130Te)=2527.518(13) keV. This is a factor of 150 more precise than the result of the AME2003 [G. Audi, Nucl. Phys. A729, 337 (2003)10.1016/j.nuclphysa.2003.11.003].

First direct double-β decay Q-value measurement of Se82 in support of understanding the nature of the neutrino

In anticipation of results from current and future double-β decay studies, we report a measurement resulting in a (82)Se double-β decay Q value of 2997.9(3) keV, an order of magnitude more precise than the currently accepted value. We also present preliminary results of a calculation of the (82)Se neutrinoless double-β decay nuclear matrix element that corrects in part for the small size of the shell model single-particle space. The results of this work are important for designing next generation double-β decay experiments and for the theoretical interpretations of their observations.

High Precision Determination of the β Decay Q(EC) Value of (11)C and Implications on the Tests of the Standard Model.

We report the determination of the Q(EC) value of the mirror transition of (11)C by measuring the atomic masses of (11)C and (11)B using Penning trap mass spectrometry. More than an order of magnitude improvement in precision is achieved as compared to the 2012 Atomic Mass Evaluation (Ame2012) [Chin. Phys. C 36, 1603 (2012)]. This leads to a factor of 3 improvement in the calculated Ft value. Using the new value, Q(EC)=1981.690(61)  keV, the uncertainty on Ft is no longer dominated by the uncertainty on the Q(EC) value. Based on this measurement, we provide an updated estimate of the Gamow-Teller to Fermi mixing ratio and standard model values of the correlation coefficients.

Precision mass measurements of neutron-rich Co isotopes beyond N=40

The region near Z=28, N=40 is a subject of great interest for nuclear structure studies due to spectroscopic signatures in

Electrochemical Etching and Characterization of Sharp Field Emission Points for Electron Impact Ionization.

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High precision Penning trap mass spectrometry of rare isotopes produced by projectile fragmentation

Ni suggesting a subshell closure at N=40. Trends in nuclear masses and their derivatives provide a complementary approach to shell structure investigations via separation energies. Penning trap mass spectrometry has provided precise measurements for a number of nuclei in this region, however a complete picture of the mass surfaces has so far been limited by the large uncertainty remaining for nuclei with N > 40 along the iron and cobalt chains. Here we present the first Penning trap measurements of

Double-beta-decay Q values of {sup 74}Se and {sup 76}Ge

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Atomic masses of {sup 6}Li,{sup 23}Na,{sup 39,41}K,{sup 85,87}Rb, and {sup 133}Cs

Co, performed at the Low-Energy Beam and Ion Trap facility at the National Superconducting Cyclotron Laboratory. In addition, we perform ab initio calculations of ground state and two-neutron separation energies of cobalt isotopes with the valence-space in-medium similarity renormalization group approach based on a particular set of two- and three-nucleon forces which predict saturation in infinite matter. We discuss the importance of these measurements and calculations for understanding the evolution of nuclear structure near

Mass of {sup 17}O from Penning-trap mass spectrometry and molecular spectroscopy: A precision test of the Dunham-Watson model in carbon monoxide

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