Precision neutron polarimetry for neutron beta decay

Precision Neutron Polarimetry for Neutron Beta Decay

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...

High Precision Neutron Beta-Decay Measurements

Precision Measurements in Neutron Decay

Free neutrons decay with a mean lifetime τn of about 15 minutes in electron, proton, and electron anti-neutrino: n → e p νe. The maximal kinetic energy of the electron is Emax(e) = 782 keV. For the proton, Emax(p) = 780 eV is three orders of magnitude smaller. Neutron decay – involving all particles of the first generation – constitutes an ideally suited laboratory to do particle physics at ver...

Non-Relativistic Limit of Neutron Beta-Decay Cross-Section in the Presence of Strong Magnetic Field

One of the most important reactions of the URCA that lead to the cooling of a neutron star, is neutron beta-decay ( ). In this research, the energy spectra and wave functions of massive fermions taking into account the Anomalous Magnetic Moment (AMM) in the presence of a strong changed magnetic field are calculated. For this purpose, the Dirac-Pauli equation for charged and neutral fermions is ...

A Backscatter-Suppressed Beta Spectrometer for Neutron Decay Studies

We describe a beta electron spectrometer for use in an upcoming experiment that will measure the beta-antineutrino correlation coefficient (a coefficient) in neutron beta decay. Electron energy is measured by a thick plastic scintillator detector. A conical array of plastic scintillator veto detectors is used to suppress events where the electron backscattered. A Monte Carlo simulation of this ...