First-forbidden $ \beta$ -decay rates, energy rates of $ \beta$ -delayed neutrons and probability of $ \beta$ -delayed neutron emissions for neutron-rich nickel isotopes

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...

Measuring Neutron Beta Decay “A” Parameter Using Ultracold Neutrons

The UCNA experiment is designed to measure the neutron decay beta asymmetry (the "A" parameter) to very high precision (<0.5%), using the ultracold neutron (UCN) source at the Los Alamos National Lab. After a successful commissioning run in 2007, data were taken in 2008 which will lead to a 1% measurement of A. In this talk, I will discuss major improvements we made in 2008, and report the stat...

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 ...

First - Forbidden Beta Decay near A = 40

Shell model calculations in the full sdpf model space are carried out for the known and possible lirst-forbidden beta decays for 34 < A i 44. The main purpose is to study the strong quenching of the unique (dJ = 2) decays, which results from the repulsive nature of the T= 1 particle-hole interaction, and the strong meson-exchange enhancement of the AJ = 0 decays. Procedures for calculating the ...

High Precision Neutron Beta-Decay Measurements