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Related papers: The Fermi function and the neutron's lifetime

200 papers

The radiative decay of the massive neutrino $\nu_i \rightarrow \nu_j \gamma$ is investigated in the framework of the Standard Model in external electromagnetic fields of various configurations: constant crossed field, constant uniform…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. A. Gvozdev , N. V. Mikheev , L. A. Vassilevskaya

In this work, the contributions from $\gamma W$-exchange in neutron $\beta$ decay are estimated at the amplitude level. Using a general form for the electromagnetic (EM) form factors (FFs) of the proton, the EM FFs of the neutron, and the…

Nuclear Theory · Physics 2025-03-18 Hui-Yun Cao , Hai-Qing Zhou

For the bound-muon decay process, the study of atomic effects on the electron spectrum near its endpoint is performed within the framework of the Fermi effective theory. The analysis takes into account for corrections due to…

Atomic Physics · Physics 2025-06-04 M. Y. Kaygorodov , Y. S. Kozhedub , A. V. Malyshev , A. O. Davydov , Y. Wu , S. B. Zhang

An exactly solvable model for a description of the two-neutrino double beta decay transition of the Fermi type is considered. By using perturbation theory an explicit dependence of the two-neutrino double beta decay matrix element on the…

Nuclear Theory · Physics 2015-06-16 Dusan Stefanik , Fedor Simkovic , Kazuo Muto , Amand Faessler

We review the status of the Standard Model theory of neutron beta decay. Particular emphasis is put on the recent developments in the electroweak radiative corrections. Given that some existing approaches give slightly different results, we…

High Energy Physics - Phenomenology · Physics 2023-11-01 Mikhail Gorchtein , Chien-Yeah Seng

We calculate the lifetime of the deuteron from dimension-six quark operators that violate baryon number by one unit. We construct an effective field theory for $|\Delta B|=1$ interactions that give rise to nucleon and $\Delta B=1$ deuteron…

Nuclear Theory · Physics 2021-08-02 F. Oosterhof , J. de Vries , R. G. E. Timmermans , U. van Kolck

As we have pointed out in (arXiv:1806.10107 [hep-ph]), the existence of neutron dark matter decay modes "n -> chi + anything", where "chi" is a dark matter fermion, for the solution of the neutron lifetime problem changes priorities and…

High Energy Physics - Phenomenology · Physics 2018-12-05 A. N. Ivanov , R. Höllwieser , N. I. Troitskaya , M. Wellenzohn , Ya. A. Berdnikov

We show that the electromagnetic moments of unstable particles (resonances) have an absorptive contribution which quantifies the change of the particle's lifetime in an external electromagnetic field. To give an example we compute here the…

High Energy Physics - Phenomenology · Physics 2009-09-01 Daniele Binosi , Vladimir Pascalutsa

A quantum mechanical wave of a finite size moves like a classical particle and shows a unique decay probability. Because the wave function evolves according to the Schr\"{o}dinger equation, it preserves the total energy but not the kinetic…

High Energy Physics - Phenomenology · Physics 2014-12-09 Kenzo Ishikawa , Yutaka Tobita

Upon increasing significantly the nuclear elongation, the beta-decay energy grows. This paper investigates within a simple yet partly microscopic approach, the transition rate of the beta decay of the 252Cf nucleus on the way to scission…

Nuclear Theory · Physics 2015-01-13 K. Pomorski , B. Nerlo-Pomorska , P. Quentin

Starting with the basic Lagrangian of the Standard Model, the radiative corrections to the neutron beta-decay are acquired. The electroweak interactions are consistently taken into consideration amenably to the Weinberg-Salam theory. The…

High Energy Physics - Phenomenology · Physics 2016-09-06 G. G. Bunatian

Limits on parameters describing physics beyond the Standard Model are presented. The most general Lorentz invariant effective Hamiltonian at the quark-lepton level involving vector, scalar and tensor operators has been used. The fits have…

Nuclear Experiment · Physics 2013-03-22 Jacek Holeczek , Michal Ochman , Elzbieta Stephan , Marek Zralek

New \textit{ab initio} calculations of the isotopic reactor antineutrino fluxes are provided with exact numerical calculations of the lepton wave functions, assuming all the decay branches are allowed GT transitions. We illustrate that the…

High Energy Physics - Phenomenology · Physics 2021-01-13 Dong-Liang Fang , Yu-Feng Li , Di Zhang

Nuclear $\beta$ decay is a key process to understand the origin of heavy elements in the universe, while the accuracy is far from satisfactory for the predictions of $\beta$-decay half-lives by nuclear models up to date. In this letter, we…

Nuclear Theory · Physics 2019-06-12 Z. M. Niu , H. Z. Liang , B. H. Sun , W. H. Long , Y. F. Niu

The influence of the electron environment on the alpha decay is elucidated. Within the frame of a simple model based on the generalized Thomas-Fermi theory of the atom, it is shown that the increase of the electron density around the parent…

Nuclear Theory · Physics 2017-04-03 Fabio Belloni

We consider interacting Fermi systems close to the unitary regime and compute the corrections to the energy density that are due to a large scattering length and a small effective range. Our approach exploits the universality of the density…

Nuclear Theory · Physics 2009-02-05 Anirban Bhattacharyya , T. Papenbrock

There is a well known anomaly between the value of the Fermi decay constant extracted from super-allowed Fermi beta-decay of nuclear isotriplets and that required by unitarity of the Cabibbo-Kobayashi-Maskawa matrix. This discrepancy…

Nuclear Theory · Physics 2010-02-17 Koichi Saito , Anthony W. Thomas

Prompted by the level of accuracy now being achieved in tests of the unitarity of the CKM matrix, we consider the possible modification of the Fermi matrix element for the $\beta$-decay of a neutron, including possible in-medium and isospin…

Nuclear Theory · Physics 2011-02-16 P. A. M. Guichon , A. W. Thomas , K. Saito

We propose formulas of the nuclear beta-decay rate that are useful in a practical calculation. The decay rate is determined by the product of the lepton and hadron current densities. A widely used formula relies upon the fact that the…

Nuclear Theory · Physics 2021-04-01 W. Horiuchi , T. Sato , Y. Uesaka , K. Yoshida

The neutron lifetime is determined for now most accurately by two methods --the so-called "beam method" and the method of neutron storage in a trap. The goal of this research is to obtain the neutron lifetime with a higher precision by…

Nuclear Experiment · Physics 2020-01-23 Valerius V. Vasiliev