相关论文: Neutron beta decay and the current determination o…
The experimental determination of V_{ud} from neutron beta decay requires accurate values of the neutron lifetime and the ratio of the weak axial-vector to vector coupling constants of the nucleon. The latter is derived from measurements of…
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…
Some recent work in nuclear beta decay related to the value of |Vud| is described along with some near-term goals for future measurements.
Precision measurements in neutron beta decay serve to determine the coupling constants of beta decay and allow for several stringent tests of the standard model. This paper discusses the design and the expected performance of the Nab…
We discuss the effect of the recent change of $V_{\rm us}$ by three standard deviations on the standard model predictions for neutron beta decay observables. We also discuss the effect the experimental error bars of $V_{\rm us}$ have on…
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…
The best value for Vud comes from superallowed 0+ to 0+ nuclear beta transitions, of which thirteen have now been measured with high precision. The current status of these measurements is described, and the result compared with that of…
In the Standard Model (SM) we calculate the decay rate of the neutron radiative beta decay to order "O(\alpha^2/\pi^2 ~ 10^{-5})", where "\alpha$"is the fine--structure constant, and radiative corrections to order "O(\alpha/\pi ~ 10^{-3})".…
Precision measurements in free neutron beta decay serve to determine the coupling constants of beta decay, and offer several stringent tests of the Standard Model. This paper describes the free neutron beta decay program planned for the…
The matrix element Vud of the CKM matrix can be determined by two independent measurements on neutron decay: the neutron lifetime tau and the ratio of coupling constants lambda, which is most precisely determined by measurements of the beta…
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…
A new measurement of the neutron $\beta$-decay asymmetry $A_0$ has been carried out by the UCNA collaboration using polarized ultracold neutrons (UCN) from the solid deuterium UCN source at the Los Alamos Neutron Science Center (LANSCE).…
The value of the $V_{ud}$ matrix element of the Cabibbo-Kobayashi-Maskawa (CKM) matrix can be derived from nuclear superallowed beta decays, neutron decay, and pion beta decay. We survey current world data for all three. Today, the most…
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…
Although well studied, the neutron still offers a unique laboratory for precise tests of Standard Model (SM) predictions. Neutron decay is free of nuclear structure corrections present in nuclear beta decays, and, with a $10^8$ times larger…
Present status, and future plans for Double Beta Decay searches are reviewed. Given the recent observations of neutrino oscillations, a possibility to observe $\beta\beta(0\nu)$~ at a neutrino mass scale suggested by present experimental…
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…
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…
In the framework of the Standard Model (SM) a theoretical description of the neutron beta decay is given at the level of 10^{-5}. The neutron lifetime and correlation coefficients of the neutron beta decay for a polarized neutron, a…
We improve the current predictions of the standard model for neutron beta decay observables and compare them with the currently available ones. Next we study their implications in the possible detection of new physics. We discuss where the…