Related papers: V_{ud} from neutron beta decay
Precision studies of $0^{+} \rightarrow 0^{+}$ superallowed $\beta$ decays provide the necessary data to test stringently the CVC hypothesis. They will also provide a value for the weak vector coupling constant and the $V_{ud}$ quark mixing…
Radiative corrections to the lifetime and angular correlation coefficients of neutron beta-decay are evaluated in effecitive field theory. We also evaluate the lowest order nucleon recoil corrections, including weak-magnetism. Our results…
We assess the ability of future neutron beta decay measurements of up to O(10^{-4}) precision to falsify the standard model, particularly the V-A law, and to identify the dynamics beyond it. To do this, we employ a maximum likelihood…
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…
The aCORN experiment uses a novel asymmetry method to measure the electron-antineutrino correlation (a-coefficient) in free neutron decay that does not require precision proton spectroscopy. aCORN completed two physics runs at the NIST…
The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. The neutron lifetime recently obtained, 878.5 +/- 0.7stat +/- 0.3sys s, is the most accurate one to date. The new result for the…
We review the status of the Standard Model theory of neutron beta decay. Particular emphasis is put on the recent developments in the electroweak radiative corrections. Given that some existing approaches give slightly different results, we…
We calculate the lifetime of the deuteron from dimension-six quark operators that violate baryon number by one unit. We construct an effective field theory for $|\Delta B|=1$ interactions that give rise to nucleon and $\Delta B=1$ deuteron…
A systematic study of the $\beta$-decay of neutron-deficient nuclei has been carried out and has provided spectroscopic information of importance for both nuclear structure and nuclear astrophysics. Following an overview of the most…
We describe a detection system designed for precise measurements of angular correlations in neutron $\beta$ decay. The system is based on thick, large area, highly segmented silicon detectors developed in collaboration with Micron…
The proton asymmetry parameter C in neutron decay describes the correlation between neutron spin and proton momentum. In this Letter, the first measurement of this quantity is presented. The result C=-0.2377(26) agrees with the Standard…
We report on a new measurement of neutron $\beta$-decay asymmetry. From the result \linebreak $A_0$ = -0.1189(7), we derive the ratio of the axial vector to the vector coupling constant $\lambda$ = ${\it g_A/g_V}$ = -1.2739(19). When…
Detection of the neutrinoless $\beta\beta$ ($0\nu\beta\beta$) decay is of high priority in the particle- and neutrino-physics communities. The detectability of this decay mode is strongly influenced by the value of the weak axial-vector…
For many decades, the main source of information on the top-left corner element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix $V_{ud}$ were superallowed nuclear beta decays with an impressive 0.01\% precision. This precision, apart…
We present new precision measurements of angular correlation coefficients in polarized neutron decay. We have obtained values for the electron asymmetry coefficient A, the neutrino asymmetry coefficient B, and for the proton asymmetry…
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 existing experimental evidence on the vector and axial-vector coupling constants, $G_V$ and $G_A$, for neutron $\beta$-decay exhibits two prominent problems: (i) the unitarity for the first row of the CKM matrix seems violated; (ii) one…
We investigate a reliability of the hypothesis of exact conservation of the charged weak hadronic vector current in the neutron $\beta^-$-decay with polarized neutron and unpolarized proton and electron. We calculate the contributions of…
The existing calculations of the nuclear matrix elements of the neutrinoless double beta-decay differ by about a factor three. This uncertainty prevents quantative interpretation of the results of experiments searching for this process. We…
The UCNA experiment was designed to measure the neutron $\beta$-asymmetry parameter $A_0$ using polarized ultracold neutrons (UCN). UCN produced via downscattering in solid deuterium were polarized via transport through a 7 T magnetic…