Related papers: Limits on Tensor Coupling from Neutron $\beta$-Dec…
Beta-decay and muon-capture experiments in nuclei are reviewed. The conserved vector current hypothesis is confirmed through the observed constancy of the vector coupling constant determined from the superallowed Fermi transitions and from…
The impact of new and highly precise neutron \b{eta} decay data is reviewed. We focus on recent results from neutron lifetime, \b{eta} asymmetry, and electron-neutrino correlation experiments. From these results, weak interaction parameters…
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…
The electroweak interaction in the Standard Model (SM) is described by a pure vector-axial-vector structure, though any Lorentz-invariant component could contribute. In this work, we present the most precise measurement of tensor currents…
$\beta$-decay rates of neutron-rich nuclei, in particular those located at neutron shell closures, play a central role in simulations of the heavy-element nucleosynthesis and resulting abundance distributions. We present $\beta$-decay…
Using the general connection between the upper limit on the neutrino mass and the upper limits on certain types of non-Standard Model interaction that can generate loop corrections to the neutrino mass, we derive constraints on some…
The two-loop contribution to the electric dipole moment (EDM) and the chromo electric dipole moment (CEDM) of an arbitrary fermion f induced by the most general renormalizable tbW coupling with complex left- and right-handed components (a_L…
The standard model weak interactions can be described by four-fermion V-A operators at low energies. New physics at the TeV scale can, however, generate the other Lorentz structures. In this talk, we review the constraints on such…
The status of tests of the standard electroweak model and of searches for new physics in allowed nuclear $\beta$ decay and neutron decay is reviewed including both theoretical and experimental developments. The sensitivity and…
We report the first measurement of angular correlation parameters in neutron $\beta$-decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for $\sim 30$ s in a Cu decay…
By extending our analysis and simulations of our $^{37}$K $\beta$-decay data set to allow the $\beta$ asymmetry with respect to nuclear spin to vary with $\beta$ energy $E_{\beta}$, we have gained sensitivity to new physics that depends on…
Data on superallowed Fermi beta decay in nuclei are compiled and electromagnetic corrections discussed. Recommended values for the weak vector coupling constant and the leading element of the Cabibbo-Kobayashi-Maskawa mixing matrix are…
The most precise value of V_{ud}, which is obtained from superallowed nuclear beta decay, leads to a violation of CKM unitarity by 2.2 sigma. Experiments are underway on two continents to test and improve this result through decay studies…
Precision measurements in allowed nuclear beta decays and neutron decay are reviewed and analyzed both within the Standard Model and looking for new physics. The analysis incorporates the most recent experimental and theoretical…
We use the present upper bound on the neutron electric dipole moment to give an estimate for the upper limit of the CP-violating couplings of the $\eta(\eta')$ meson to the neutron. Using this result, we derive constraints on the…
We provide updated bounds on non-standard neutrino interactions based on data from the Planck satellite as well as auxiliary cosmological measurements. Two types of models are studied - A Fermi-like 4-point interaction and an interaction…
Neutron beta decay is one of the most fundamental processes in nuclear physics and provides sensitive means to uncover the details of the weak interaction. Neutron beta decay can evaluate the ratio of axial-vector to vector coupling…
The Nab collaboration will study free neutron beta decay at the Spallation Neutron Source at Oak Ridge National Lab. A neutron decays into a proton, an electron and an anti-neutrino in this process, where the energy of the outgoing protons…
We use the constraints arising from primordial nucleosynthesis to bound the strength $F$ of non-standard neutrino-neutrino interactions, when the right-handed neutrinos participate in the interaction. We find $F < 3 \times 10^{-3}\ G_F$,…
We study the recently measured beta-decay of $^{70}$Kr into $^{70}$Br within the framework of the large-scale shell model. The enhancement in the Gamow-Teller (GT) transition strength in $^{70}$Br compared to the $\beta$-decay of the…