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Related papers: Neutron beta-decay, Standard Model and cosmology

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We present a new value for the neutron lifetime of 878.5 +- 0.7 stat. +- 0.3 syst. This result differs from the world average value (885.7 +- 0.8 s) by 6.5 standard deviations and by 5.6 standard deviations from the previous most precise…

The analysis of the data on measurements of the neutron lifetime is presented. A new most accurate result of the measurement of neutron lifetime [Phys. Lett. B 605 (2005) 72] 878.5 +/- 0.8 s differs from the world average value [Phys. Lett.…

Nuclear Experiment · Physics 2014-11-21 A. P. Serebrov , A. K. Fomin

The analysis of experiments on measuring neutron lifetime has been made. The latest most accurate result of measuring neutron lifetime [Phys. Lett. B 605, 72 (2005)] 878.5 \pm 0.8 s differs from the world average value [Phys. Lett. B 667, 1…

Nuclear Experiment · Physics 2011-04-22 A. P. Serebrov , A. K. Fomin

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

The article provides a theoretical substantiation for a significant increase in the level of accuracy in determining the neutron lifetime using an alternative concept of neutron beta decay. Neutrons are distributed among different subsets…

Nuclear Theory · Physics 2023-08-03 V. V. Vasiliev

The neutron lifetime, $\tau$ = 880.2 $\pm$ 1.0 sec , is an important parameter for particle physics and cosmology. There is, however, an 8.4 sec (4.0$\,\sigma$) deviation between the measured value of the neutron lifetime using two methods…

Instrumentation and Detectors · Physics 2018-12-26 Naoyuki Sumi , Hidetoshi Otono , Tamaki Yoshioka , Kenji Mishima , Yasuhiro Makida

The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A…

Nuclear Experiment · Physics 2014-11-14 F. E. Wietfeldt

We establish the feasibility of measuring the neutron lifetime via an alternative, space-based class of methods, which use neutrons generated by galactic cosmic ray spallation of planets' surfaces and atmospheres. Free neutrons decay via…

We calculated the median as well as weighted mean central estimates for the neutron lifetime, from a subset of measurements compiled in the 2019 update of the Particle Data Group (PDG). We then reconstruct the error distributions for the…

High Energy Physics - Phenomenology · Physics 2020-01-29 Ashwani Rajan , Shantanu Desai

We explore the effect of neutron lifetime and its uncertainty on standard big-bang nucleosynthesis (BBN). BBN describes the cosmic production of the light nuclides $^1{\rm H}$, ${\rm D}$, $^3{\rm H}$+$^3{\rm He}$, $^4{\rm He}$, and $^7{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-08 Tsung-Han Yeh , Keith A. Olive , Brian D. Fields

We present the status of current US experimental efforts to measure the lifetime of the free neutron by the "beam" and "bottle" methods. BBN nucleosynthesis models require accurate measurements with 1 second uncertainties, which are…

The precise value of the mean neutron lifetime, $\tau_n$, plays an important role in nuclear and particle physics and cosmology. It is a key input for predicting the ratio of protons to helium atoms in the primordial universe and is used to…

Free neutrons have a measured lifetime of 880 s, but disagreement between existing laboratory measurements of ~10 s have persisted over many years. This uncertainty has implications for multiple physics disciplines, including standard-model…

Nuclear Experiment · Physics 2020-12-30 David J. Lawrence , Jack T. Wilson , Patrick N. Peplowski

We analyse the sensitivity of all experimentally observable asymmetries and energy distributions for the neutron beta-decay with a polarised neutron and unpolarised decay proton and electron and the lifetime of the neutron to contributions…

High Energy Physics - Phenomenology · Physics 2018-11-06 A. N. Ivanov , M. Pitschmann , N. I. Troitskaya

A neutron decays into a proton, an electron, and an anti-neutrino through the beta-decay process. The decay lifetime ($\sim$880 s) is an important parameter in the weak interaction. For example, the neutron lifetime is a parameter used to…

The neutron lifetime is important in understanding the production of light nuclei in the first minutes after the big bang and it provides basic information on the charged weak current of the standard model of particle physics. Two different…

The past two decades have yielded several new measurements and reanalysis of older measurements of the neutron lifetime. These have led to a 4.4 standard deviation discrepancy between the most precise measurements of the neutron decay rate…

In this paper we review the role of the neutron lifetime and discuss the present status of measurements. In view of the large discrepancy observed by the two most precise individual measurements so far we describe the different techniques…

High Energy Physics - Experiment · Physics 2014-11-18 Stephan Paul

In the framework of the Standard Model (SM) a theoretical description of the neutron beta decay is given at the level of 10^{-5}. The neutron lifetime and correlation coefficients of the neutron beta decay for a polarized neutron, a…

High Energy Physics - Phenomenology · Physics 2021-09-08 A. N. Ivanov , R. Höllwieser , N. I. Troitskaya , M. Wellenzohn , Ya. A. Berdnkov

We summarize our recent proposal of explaining the discrepancy between the bottle and beam measurements of the neutron lifetime through the existence of a dark sector, which the neutron can decay to with a branching fraction 1%. We show…

High Energy Physics - Phenomenology · Physics 2018-11-07 Bartosz Fornal , Benjamin Grinstein
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