Related papers: On V_ud determination from neutron decay
The effect of the pion propagator on the $\beta$-decay of neutron is investigated to account for the ratio of the axial-vector to the vector part $g_A/g_V$ by including the pole term. A suggestion is made that the sign and the size of the…
We compute the electromagnetic corrections to neutron beta decay using a low-energy hadronic effective field theory. We identify and compute new radiative corrections arising from virtual pions that were missed in previous studies. The…
The interest, the status and the perspectives of various experiments in neutron and nuclear beta-decay, muon-decay and pion-decays are discussed. The talk is segmented into a discussion of the decay-rates and of the energy-spectra and…
Nuclear beta decays between (J^pi,T) = (0^+,1) analog states yield the best value for the Vud element of the Cabibbo-Kobayashi-Maskawa matrix. Current world data establish the corrected Ft values of 14 separate superallowed transitions to a…
After a decade of no measurements of pion and muon rare decays, PIBETA, a new experimental program is producing its first results. We report on a new experimental study of the pion beta decay, Pi(+) -> Pi(0) e(+) Nu, the Pi(e2 gamma)…
We lay out a novel formalism to connect the isospin-symmetry breaking correction to the rates of superallowed nuclear beta decays, $\delta_\text{C}$, to the isospin-breaking sensitive combinations of electroweak nuclear radii that can be…
The neutrino produced in the pion decay reveals a new diffraction phenomenon due to many-body interactions in an intermediate time region when wave functions of the parent and daughters overlap. Because of diffraction, the probability to…
We consider radiative \beta--decay of the neutron in heavy baryon chiral perturbation theory, with an extension including explicit \Delta degrees of freedom. We compute the photon energy spectrum as well as the photon polarization; both…
The most general amplitude for the radiative pion decay pi -> e nu gamma including terms beyond V-A theory is considered. The experimental constraints on the decay amplitude components are discussed. A model independent presentation of the…
We review the determination of Vud from nuclear mirror transitions and describe current experimental and theoretical efforts aimed at improving its precision.
Precision measurements of neutron decay offer complementary access to particle physics at small distance scales or high energies. In particular they allow tests of the V-A structure of the weak interaction. Among many experimental…
The consideration is presented of possible neutron experiments to search for new short-range spin-dependent forces. The spin-dependent nucleon-nucleon interaction between neutron and nuclei may cause different effects: phase shift of a…
Superallowed $0^+\rightarrow 0^+$ transitions between $T=1$ nuclei have been a perfect avenue avenue for determining the Cabibbo-Kobayashi-Maskawa matrix element $V_{ud}$, which imposes powerful constraints on physics beyond the Standard…
We review the recent measurements of the rare pion decays: Pi+ -> Pi0 e+ Nu [pion beta, Pi_(e3), or Pi_beta decay], radiative decay Pi+ -> e+ Nu Gamma [Pi_(e2Gamma) or RPD], and Pi+ -> e+ Nu [Pi_(e2)] decay, as well as the radiative muon…
Motivated by the findings of the OPERA experiment, we discuss the hypothesis that neutrino propagation does not obey Einstein special relativity. Under a minimal set of modifications of the standard model Lagrangian, we consider the…
The pure lepton decay of the polarized muon is considered, accounting for a new tensor interaction which is outside of the Michel local interactions. This interaction leads to new energy distribution and polarization of the final charged…
Nucleon spin fluctuations in a dense medium reduce the ``naive'' values of weak interaction rates (neutrino opacities, neutrino emissivities). We extend previous studies of this effect to the degenerate case which is appropriate for neutron…
Prompted by the level of accuracy now being achieved in tests of the unitarity of the CKM matrix, we consider the possible modification of the Fermi matrix element for the $\beta$-decay of a neutron, including possible in-medium and isospin…
Conventional theories of nuclear interactions predict a net increase in the distribution of virtual pions in nuclei relative to free nucleons. Analysis of data from several nuclear experiments has led to claims of evidence against such a…
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…