Simultaneous Measurements of the Beta Neutrino Angular Correlation in $^{32}$Ar Pure Fermi and Pure Gamow-Teller Transitions using Beta-Proton Coincidences

Araujo-Escalona, V.; Atanasov, D.; Fléchard, X.; Alfaurt, P.; Ascher, P.; Blank, B.; Daudin, L.; Gerbaux, M.; Giovinazzo, J.; Grévy, S.; Kurtukian-Nieto, T.; Liénard, E.; Quéméner, G.; Severijns, N.; Vanlangendonck, S.; Versteegen, M.; Zakoucky, D.

doi:10.48550/arxiv.1906.05135

Cited by 3 publications

(3 citation statements)

References 22 publications

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“…Observing table II, and provided that systematics and theoretical corrections are under control [6], the detection of 10 6 recoil ions from 23 Ne decay already improves on the state of the art. Nevertheless, to be competitive with ongoing and planned campaigns involving pure GT branches [31,32,[82][83][84][85], roughly 10 7 events are desired. 18 Ne decays mainly to the ground state of 18 F through a pure GT transition, and to an excited state by a superallowed Fermi transition.…”

Section: Opportunities With Neon Isotopesmentioning

confidence: 99%

Decay microscope for trapped neon isotopes

et al. 2020

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We review the design, simulation, and tests, of a detection system for measuring the energy distribution of daughter nuclei recoiling from the beta-decay of laser trapped neon isotopes. This distribution is sensitive to several new physics effects in the weak sector. Our 'decay microscope' relies on imaging the velocity distribution of high energy recoil ions in coincidence with electrons shaken-off in the decay. We demonstrate by way of Monte-Carlo simulation, that the nuclear microscope increases the statistical sensitivity of kinematic measurements to the underlying energy distribution, and limits the main systematic bias caused by discrepancy in the trap position along the detection axis.

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Section: Opportunities With Neon Isotopesmentioning

confidence: 99%

Decay microscope for trapped neon isotopes

et al. 2020

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“…[38] stand to build upon the comprehensive evaluation of T = 1 superallowed 0 + → 0 + decays by Towner and Hardy [39] testing the Conserved Vector Current hypothesis and consequentially providing the most precisely known element in the quark-mixing Cabibbo-Kobayashi-Maskawa matrix. Scalar currents in the weak interaction can be probed by measuring the beta-neutrino angular correlation in the decays of T = 2 nuclei and modern programs stand to improve on earlier work done with 32 Ar [40] (TAMUTRAP [41,42], WISArD [43,44]). Additionally, one may set limits on electron-sterile neutrino mixing from precision measurements of the beta-particle energy distribution [45,46].…”

Section: B Outlookmentioning

confidence: 99%

First Penning trap mass measurement of $^{36}$Ca

Surbrook,

Bollen,

Brodeur

et al. 2020

Preprint

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Background: Isobaric quintets provide the best test of the isobaric multiplet mass equation (IMME) and can uniquely identify higher order corrections suggestive of isospin symmetry breaking effects in the nuclear Hamiltonian. The Generalized IMME (GIMME) is a novel microscopic interaction theory that predicts an extension to the quadratic form of the IMME. Only the A = 20, 32 T = 2 quintets have the exotic Tz = −2 member ground state mass determined to high-precision by Penning trap mass spectrometry.Purpose: To establish A = 36 as the third high-precision T = 2 isobaric quintet with the Tz = −2 member ground state mass measured by Penning trap mass spectrometry and provide the first test of the predictive power of the GIMME.Method: A radioactive beam of neutron-deficient 36 Ca was produced by projectile fragmentation at the National Superconducting Cyclotron Laboratory. The beam was thermalized and the mass of 36 Ca + and 36 Ca 2+ measured by the Time of Flight -Ion Cyclotron Resonance method in the LEBIT 9.4 T Penning trap.Results: We measure the mass excess of 36 Ca to be ME= −6483.6(56) keV, an improvement in precision by a factor of 6 over the literature value. The new datum is considered together with evaluated nuclear data on the A = 36, T = 2 quintet. We find agreement with the quadratic form of the IMME given by isospin symmetry, but only coarse qualitative agreement with predictions of the GIMME. Conclusion:A total of three isobaric quintets have their most exotic members measured by Penning trap mass spectrometry. The GIMME predictions in the T = 2 quintet appear to break down for A = 32 and greater.

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“…Another characteristic of T = 2 decays that can benefit standard-model tests is that the isobaric analog states of the daughters tend to be unbound to proton emission. The β − ν correlation coefficient can be kinematically extracted from precision measurements of the proton energy spectrum for comparison to the standardmodel value and this has been carried out for the case of 32 Ar [5,6] to search for scalar-current contributions. A precisely measured Q EC value for the superallowed decay has been prerequisite to an accurate extraction of the β − ν correlation [5,7].…”

Section: Introductionmentioning

confidence: 99%

Superallowed $0^+ \rightarrow 0^+$ $β$ decay of $T =2$ $^{20}$Mg: $Q_{\textrm{EC}}$ value and $βγ$ branching

Glassman,

Pérez-Loureiro,

Wrede

et al. 2019

Preprint

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Background: Superallowed 0 + → 0 + β decays are used for precision tests of the standard electro-weak model. The decays of isospin T = 2 nuclides can be used to test theoretical isospin symmetry breaking corrections applied to extract the CKM matrix element V ud from T = 0, 1 decays by measuring precise f t values and also to search for scalar currents using the β − ν angular correlation kinematically imprinted in the β delayed proton spectrum. Key ingredients include the QEC value and branching of the superallowed transition and the half life of the parent.Purpose: To determine a precise experimental QEC value for the superallowed 0 + → 0 + β decay of T = 2 20 Mg and the intensity of 20 Mg β-delayed γ rays through the isobaric analog state in 20 Na.Method: A beam of 20 Mg was produced using the in-flight method and implanted into a plastic scintillator surrounded by an array of high-purity germanium detectors used to detect β-delayed γ rays. The high-resolution γ-ray spectrum was analyzed to measure the γ-ray energies and intensities. Results:The intensity of 20 Mg β-delayed γ rays through the isobaric analog state in 20 Na was measured to be (1.60 ± 0.04stat ± 0.15syst ± 0.15 theo ) × 10 −4 , where the uncertainties are statistical, systematic, and theoretical, respectively. The QEC value for the superallowed transition was determined to be 4128.7 ± 2.2 keV based on the measured excitation energy of 6498.4 ± 0.2stat ± 0.4syst keV and literature values for the ground-state masses of 20 Na and 20 Mg. Conclusions:The β-delayed γ-decay branch and QEC value are now sufficiently precise to match or exceed the sensitivity required for current low-energy tests of the standard model. Future work on the f t value should focus on improving the precision of the β-delayed proton-decay branch and the half life to match the precision of the present measurements.

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Simultaneous Measurements of the Beta Neutrino Angular Correlation in $^{32}$Ar Pure Fermi and Pure Gamow-Teller Transitions using Beta-Proton Coincidences

Cited by 3 publications

References 22 publications

Decay microscope for trapped neon isotopes

Decay microscope for trapped neon isotopes

First Penning trap mass measurement of $^{36}$Ca

Superallowed $0^+ \rightarrow 0^+$ $β$ decay of $T =2$ $^{20}$Mg: $Q_{\textrm{EC}}$ value and $βγ$ branching

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