This article is about the interplay between the Standard Model of elementary particle physics and neutron β-decay. Since the Fermi decay constant is known from muon decay, the Standard Model describes neutron β-decay with only two additional parameters. One parameter is the first entry |Vud| of the CKMmatrix. The other one is λ, the ratio of the vector coupling constant and the axial vector con...

Simple arguments concerning power and acceleration efficiency show that ultra-high energy cosmic rays (UHECRS) with energies > ∼ 10 eV could originate from GRBs. Neutrons formed through photo-pion production processes in GRB blast waves leave the acceleration site and travel through intergalactic space, where they decay and inject a very energetic proton and electron component into intergalacti...

Modern versions of Aston’s mass spectrometer enable measurements of two quantities – isotope abundances and masses – that tell the Sun’s origin and operation. Isotope analyses of meteorites, the Earth, Moon, Mars, Jupiter, the solar wind, and solar flares over the past 45 years indicate that fresh, poorly-mixed, supernova debris formed the solar system. The iron-rich Sun formed on the collapsed...

The abBA collaboration is developing a new type of field-expansion spectrometer for a measurement of the three correlation coefficients a, A, and B and the shape parameter b. The measurement of A and B requires precision neutron polarimetry. We will polarize a pulsed cold neutron beam from the SNS using a (3)He neutron spin filter. The well-known polarizing cross section for n-(3)He has a 1/v d...

Abstract The hypothesis that neutrons might decay into dark matter is explored using neutron stars as a testing ground. It found in order to obtain with masses at the upper end of those observed, must experience relatively strong self-interaction. Conservation baryon number and energy then require star undergo some heating, decrease radius, leading an increase speed rotation over period days.

We explore the suggestion that neutron lifetime puzzle might be resolved by neutrons decaying into dark matter through process, n \rightarrow \chi\chi\chi, with \chi having a mass one third of neutron. In particular, we examine consequences such decay mode for properties stars. Unlike an earlier suggested mode, in order to satisfy constraints on star and tidal deformability, there is no need st...

In this short note we discuss the influence of power-law magnetic field decay on the evolution of old accreting isolated neutron stars. We show, that, contrary to exponential field decay (Popov & Prokhorov 2000), no additional restrictions can be made for the parameters of power-law decay from the statistics of isolated neutron star candidates in ROSAT observations. We also briefly discuss the ...

Introduction: In recent years, the use of neutrons has increased in various fields such as medicine and industry. One of the important applications of neutrons is in medical research. Neutrons have greater linear energy transfer than gamma rays and are considered more dangerous radiation. Hence, the detection and determination of neutron dose is a very important and vital issu...