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 correlations. The impact on various scenarios of ”new physics” is briefly mentioned ; leftright symmetric models are discussed in more detail and the informations...

We calculate the coupled thermal evolution and magnetic field decay in relativistic model neutron stars threaded by superstrong magnetic fields (B > 10 G). Our main goal is to evaluate how such “magnetars” evolve with time and how field decay modifies the transitions to core superfluidity and cooling dominated by surface X-ray emission. Observations of a thermal X-ray spectral component and fas...

Core collapse of massive stars and binary neutron stars or black hole-neutron star binary mergers are likely progenitors of long and short duration gamma-ray bursts respectively. Neu-tronized material in the former and neutron star material in the latter are ejected by the central engine implying a neutron-rich jet outflow. A free neutron, however, beta decays to a proton, an electron (beta) an...

We discuss how detection of gamma-ray emission from the decay of r-process nuclei can improve our understanding of r-process nucleosynthesis. We find that a gamma-ray detector with a sensitivity of ∼ 10 −7 γ cm −2 s −1 at E γ ≈ 100–700 keV may detect the emission from the decay of 194 Os produced in a future Galactic supernova. In addition, such a detector may detect the emission from the decay...

The spectrum of neutrons emitted after the B-decay of ~Li has been measured with a large time-of-flight array. The spectrum exhibits six peaks corresponding to neutron emission from known states in the l lBe daughter nucleus. The measured branching ratios indicate significant feeding to states over a broad energy range. The energies and parities of the states are in very good agreement with the...

The corrections to muon decay due to electromagnetic interactions have been recalculated. Our results differ from those of Behrends, Finkelstein, and Sirlin, because those authors used an inconsistent method for handling the infrared divergences which arise separately in the real and virtual processes. The disagreement is especially significant near the end of the electron (positron) spectrum w...

We investigate three mechanisms that promote the loss of magnetic flux from an isolated neutron star. Ohmic decay produces a diffusion of the magnetic field with respect to the charged particles. It proceeds at a rate that is inversely proportional to the electric conductivity and independent of the magnetic field strength. Ohmic decay occurs in both the fluid core and solid crust of a neutron ...

A new approach to fast-neutron dosimeq is described. It involves circulating a liquid with dissolved chemicals between a localized neutron field and a remote area where neutron-induced radioactivities are measured continuously. This approach employs reactions whch generate relatively short-lived radioactive byproducts. Sensitivity to the neutron energy spectrum is achieved by choosing several r...

Although neutron diffraction was first observed using radioactive decay sources shortly after the discovery of the neutron, it was only with the availability of higher intensity neutron beams from the first nuclear reactors, constructed as part of the Manhattan Project, that systematic investigation of Bragg scattering became possible. Remarkably, at a time when the war effort was singularly fo...