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Related papers: Neutron Lifetime and Axial Coupling Connection

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The neutron lifetime has been measured by comparing the decay rate with the reaction rate of $^3$He nuclei of a pulsed neutron beam from the spallation neutron source at the Japan Proton Accelerator Research Complex (J-PARC). The decay rate…

We present the first and complete dispersion relation analysis of the inner radiative corrections to the axial coupling constant $g_A$ in the neutron $\beta$-decay. Using experimental inputs from the elastic form factors and the…

High Energy Physics - Phenomenology · Physics 2021-10-14 Mikhail Gorchtein , Chien-Yeah Seng

The current knowledge of the neutron $\beta$-decay lifetime has come under scrutiny as of late due to large disagreements between recent precise measurements. Measurements using magnetically trapped Ultra-Cold Neutrons (UCNs) offer the…

Nuclear Experiment · Physics 2009-02-05 Kent Leung , Oliver Zimmer

It is noted that, but for one missing piece -- proton decay -- the evidence in support of grand unification is now strong. It includes: (i) the observed family-structure, (ii) the meeting of the gauge couplings, (iii) neutrino-oscillations,…

High Energy Physics - Phenomenology · Physics 2014-11-17 Jogesh C. Pati

In this paper, $\beta^-$ and $\beta$-delayed neutron decays of $^{46,47}$Cl are reported from an experiment carried out at the National Superconducting Cyclotron Laboratory using the Beta Counting System. The half-lives of both $^{46}$Cl…

The correlations of the decay products following the beta decay of nuclei have a long history of providing a low-energy probe of the fundamental symmetries of our universe. Over half a century ago, the correlation of the electrons following…

Instrumentation and Detectors · Physics 2014-08-08 D. Melconian , R. S. Behling , B. Fenker , M. Mehlman , P. D. Shidling , M. Anholm , D. Ashery , J. A. Behr , A. Gorelov , G. Gwinner , K. Olchankski , S. Smale

The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST…

The $\textit{axial coupling of the nucleon}$, $g_A$, is the strength of its coupling to the $\textit{weak}$ axial current of the Standard Model of particle physics, in much the same way as the electric charge is the strength of the coupling…

We report the results of an improved determination of the triple correlation $D P \cdot(p_{e}\times p_{\nu})$ that can be used to limit possible time-reversal invariance in the beta decay of polarized neutrons and constrain extensions to…

A number of nuclear decay anomalies have been reported in the literature, which purport to show periodic variations in the decay rates of certain radioisotopes. If these reports reflect reality, they would necessitate a seismic shift in our…

High Energy Physics - Phenomenology · Physics 2023-11-23 Xin Zhang , Nick Houston , Tianjun Li

The neutron $\beta$-decay asymmetry parameter $A_0$ defines the correlation between the spin of the neutron and the momentum of the emitted electron, which determines $\lambda=\frac{g_{A}}{g_{V}}$, the ratio of the axial-vector to vector…

A new method of measurements of angular correlations in neutron decay is proposed. It excludes the need of precise spectroscopy of decay products and thus promises to make the systematic uncertainties of the results much lower than in…

Nuclear Experiment · Physics 2007-05-23 B. Yerozolimsky

We consider the possibility of solar neutrino decay as a sub-leading effect on their propagation between production and detection. Using current oscillation data, we set a new lower bound to the $\nu_2$ neutrino lifetime at $\tau_2\, /\,…

High Energy Physics - Phenomenology · Physics 2016-08-10 R. Picoreti , M. M. Guzzo , P. C. de Holanda , O. L. G. Peres

It was recently suggested that the discrepancy between two methods of measuring the lifetime of the neutron may be a result of an unseen decay mode into a dark matter particle which is almost degenerate with the neutron. We explore the…

Nuclear Theory · Physics 2018-05-09 T. F. Motta , P. A. M. Guichon , A. W. Thomas

The UCN$\tau$ experiment is designed to measure the lifetime $\tau_{n}$ of the free neutron by trapping ultracold neutrons (UCN) in a magneto-gravitational trap. An asymmetric bowl-shaped NdFeB magnet Halbach array confines…

A complete analysis of proton recoil asymmetry in neutron decay in the first order of radiative and recoil corrections is presented. The possible contributions from new physics are calculated in terms of low energy coupling constants, and…

High Energy Physics - Phenomenology · Physics 2008-11-26 V. Gudkov

Neutrons study a number of hot topics from the field of particle physics and cosmology: Recent measurements of various mixed American-British-French-German-Hungarian-Japan-Russian groups of researchers determine the strength of the weak…

High Energy Physics - Experiment · Physics 2007-05-23 Hartmut Abele

We estimate the values of Yukawa couplings of a light pseudoscalar A with a mass of about 17 MeV, which would explain the $^8Be$ anomaly observed in the Atomki pair spectrometer experiment. The resulting couplings of A to up and down type…

High Energy Physics - Phenomenology · Physics 2016-10-31 Ulrich Ellwanger , Stefano Moretti

Neutron-antineutron ($n-\bar n$) oscillations in the deuteron are considered. Specifically, the deuteron lifetime is calculated in terms of the free-space $n-\bar n$ oscillation time $\tau_{n-\bar n}$ based on $NN$ and $\bar NN$…

High Energy Physics - Phenomenology · Physics 2020-02-27 Johann Haidenbauer , Ulf-G. Meißner