The beta spectrum of tritium has been studied with a pi square root (13)/2-spectrometer. The source consisted of tritium in the atomic form embedded in a metal-dioxide lattice. The measured spectrum was analysed down to 14 keV. All fitting parameters used, in addition to the mass parameter mnu , could be checked by independently determined physical values. No evidence for a non-vanishing antineutrino mass or a mixed state with a heavy antineutrino admixture in the mass region from 0.010 to 4 keV/c2 was found. Typical upper limits for the amplitude were 1.8*10-3 for a 3 keV/c2 and 16*10-3 for a 0.6 keV/c2 heavy neutrino branch at 95% confidence. The value of the electron antineutrino mass was determined to be mnu =15-15+32 eV/c2. The mass difference Delta M(3H-3He) was found to be 18597+or-14 eV/c2. Experimental effects influencing the determination of the rest mass are discussed and considered in the results.
The distributions of residual nuclei after annihilation of stopped antiprotons in 92M0, 95M0, 98M0 and 165H0 targets have been measured by means of the induced radioactivity. In the case of the 165H0 target the residual nucleus ~ 16Te was observed thus indicating that about 50 nucleons may be emitted after annihilation. The distributions have also been calculated with two versions of an intranuclear cascade model. The agreement between theory and experiment is satisfactory. The effects of heavy mesons in the annihilation process, of local reduction of the nuclear density during the intranuclear cascade and of multifragmentation are discussed.
We report our investigations of x rays emitted during the muonic cascade in hydrogen employing charge coupled devices as x-ray detectors. The density dependence of the relative x-ray yields for the muonic hydrogen lines (K a , K b , and K g ) has been measured at densities between 0.001 15 and 0.97 of liquid hydrogen density. In this density region collisional processes dominate the cascade down to low energy levels. A comparison with recent calculations is given in order to demonstrate the influence of Coulomb deexcitation. [S0031-9007 (98)05692-0]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.