Related papers: Nab: Measurement Principles, Apparatus and Uncerta…
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…
Measurements of the beta-neutrino correlation coefficient (a$_{\beta\nu}$) in nuclear beta decay, together with the Fierz interference term (b$_F$), provide a robust test for the existence of exotic interactions beyond the Standard Model of…
The Nab experiment at Oak Ridge National Laboratory, USA, aims to measure the beta-antineutrino angular correlation following neutron $\beta$ decay to an anticipated precision of approximately 0.1\%. The proton momentum is reconstructed…
The aCORN experiment measures the neutron decay electron-antineutrino correlation ($a$-coefficient) using a novel method based on an asymmetry in proton time-of-flight for events where the beta electron and recoil proton are detected in…
We review the current status of precision measurements in allowed nuclear beta decay, including neutron decay, with emphasis on their potential to look for new physics beyond the standard electroweak model. The experimental results are…
Spectrum shape measurements in nuclear $\beta$ decay can be used to test physics beyond the Standard Model with results being complementary to high-energy collider experiments. In particular, Beyond Standard Model sensitivity of the weak…
Measurements of neutron beta decay observables required to determine $|V_{ud}|$ are reaching the 0.1% accuracy. In this paper we review the calculation of the decay rate of this process, discuss its relevant uncertainties, and obtain an…
Limits on parameters describing physics beyond the Standard Model are presented. The most general Lorentz invariant effective Hamiltonian at the quark-lepton level involving vector, scalar and tensor operators has been used. The fits have…
Precision measurements in nuclear beta decay offer a sensitive window to search for new physics beyond the standard electroweak model and allow also the determination of the fundamental weak vector coupling in processes involving the…
With more intense sources of cold and ultracold neutrons becoming available and with improved experimental techniques being developed, determination of |Vud| from neutron beta decay with a similar precision to that from from superallowed…
The neutron $\beta$-decay asymmetry parameter $A_0$ defines the correlation between the spin of the neutron and the momentum of the emitted electron, which determines $\lambda=\frac{g_{A}}{g_{V}}$, the ratio of the axial-vector to vector…
The current most stringent constraints on exotic scalar or tensor couplings in neutron and nuclear $\beta$ decay, involving left-handed neutrinos, are obtained from the Fierz interference term. The sensitivity to this term in a correlation…
A new measurement of the neutrino asymmetry parameter B in neutron decay, the angular correlation between neutron spin and anti-neutrino momentum, is presented. The result, B=0.9802(50), agrees with the Standard Model expectation and…
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…
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…
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…
The beta decay of the free neutron provides several probes to test the Standard Model of particle physics as well as to search for extensions thereof. Hence, multiple experiments investigating the decay have already been performed, are…
The NA61/SHINE strong interaction programme aims to explore the phase diagram of the strongly interacting matter. The main physics goals are the study of the onset of deconfinement and the search for the critical point of the strongly…
Precision experiments at low energies probing weak interaction are a very promising and complementary tool for investigating the structure of the electro-weak sector of the standard model, and for searching for new phenomena revealing signs…
We present a precision measurement of the axial-vector coupling constant $g_A$ in the decay of polarized free neutrons. For the first time, a pulsed cold neutron beam was used for this purpose. By this method, leading sources of systematic…