Search results for "decay [meson]"

Note on the decay of200Au

1972

Gamma and beta rays from the decay of200Au (48.4 min) were studied employing Ge(Li) and plastic detectors in various singles and coincidence arrangements. The intensity of the β-branch to the ground state of200Hg was determined as 79%, and the disintegration energy of200Au to be asQβ=2.26 ± 0.06 MeV. A tentative spin and parity assignment of (1,2)+ is proposed for levels at 1515.2 and 1972.5 keV in 200Hg

Directional correlations of some γ-ray cascades in200Hg

1971

Directional correlation functions of 10 γ-ray cascades in200Hg have been measured using a200Tl source and a Ge(Li)-NaI(Tl) coincidence spectrometer arrangement. Values of the mixing parameter δ for several transitions are determined, and the spin assignments for the following levels in200Hg are established (level energies are given in keV): 1029.4 (0+), 1254.2 (2+), 1573.7 (2+), 1593.4 (2+), 1641.5 (2+), 1730.9 (2+) and 1775.6 (3+).

Decay of 14.6 h90Nb

1975

The disintegration of 14.6 h90Nb produced by bombarding natural Zr with 13 MeV protons was investigated by methods of γ-ray spectrometry. Results from singles, coincidence and anti-Compton spectrometer measurements are reported. A decay scheme is proposed including excited states in90Zr at 1761, 2186.4, 2319.1, 2739.4, 2747.9, 3077.0, 3448.2, 3589.5, 3977.1, 4232.4, 4319.5, 4375.4, 4541.6, 5060.0, 5164.6 and 5432.9 keV. Over 10 γ-ray transitions and several levels proposed in an earlier investigation are shown to be in error.

Decay of the heaviest isotope of neodymium:154Nd

1985

The neutron-rich isotope154Nd has been separated from235U fission products with the HELIum-jet On-line mass Separator HELIOS and investigated by γ-singles, γγ- and γX-coincidence measurements. The Z- and A-assignment have been confirmed by the observation of promethium KX-rays and by the genetic relationship to the daughter product 1.7-min154Pm. A half-life of 26±2 s has been obtained for154Nd, and a partial decay scheme is proposed. A 40 s activity previously assigned to154Nd could not be confirmed.

High-precision mass measurement ofS31with the double Penning trap JYFLTRAP improves the mass value forCl32

2010

The decay of 0.57 s114Cs

1980

Fusion reactions between58Ni projectiles and58Ni target nuclei were used to produce114Cs activity, which was studied by on-line mass separation and decay spectroscopy. The obtained half-life of 0.57±0.02 s and the probability ratio of 44±3 between betadelayed proton and beta-delayed alpha emission represent data with improved precision. The absolute branching ratios for both particle decay modes were determined to be (7 ±2)×10−2 and (1.6±0.6)×10−3, respectively. These branching ratios and the shapes of particle spectra are discussed with reference to the statistical model calculations. Groundstate alpha decay of114Cs was observed with an alpha energy of 3,226±30 keV and a branching ratio of…

Neutrinoless double beta decay to excited collective 0+ states

2000

Abstract The many recently performed experiments to study the two-neutrino double beta (2 νββ ) decay to the first excited 0 + final state encourage similar experiments to be done for the neutrinoless double beta (0 νββ ) decay. Based on the accumulated theoretical and experimental information on the 2 νββ decays one could hope that the 0 νββ decay to the excited 0 + state would be very efficient in restricting the parameter space of modern particle-physics theories. In this article the 0 νββ decays of 76 Ge and 82 Se to excited collective 0 + states are studied within a realistic nuclear model. It is found that the lower limits for the half-lives of these decays are of the order of 10 27 y…

Λ Decay Induced by Two Nucleons

1995

The decay of Λ hypernuclei induced by two nucleons is revised, along with its implications in the experimental determination of the ratio of neutron- to proton-stimulated Λ decay.

Structure And Decay Of Neutron-Rich Nuclides In The 115 ≤ A ≤ 138 Mass Range And r-Process Nucleosynthesis

2005

The structure and decay of neutron‐rich r‐process nuclides has been studied by a variety of means that take advantage of enhanced selectivity to permit identification of exotic nuclides. New level structures are presented for 134,135Sb along with data for Ag isomers and Cd yrast structures. Some of the properties measured play an important role in calculations of the yields of elements and isotopes produced in r‐process nucleosynthesis that takes place at high temperature in the presence of large densities of neutrons.

Mass measurements on stable nuclides in the rare-earth region with the Penning-trap mass spectrometer RIGA-TRAP

2011

The masses of 15 stable nuclides in the rare-earth region have been measured with the Penning-trap mass spectrometer TRIGA-TRAP. This is the first series of absolute mass measurements linking these nuclides to the atomic-mass standard $^{12}\mathrm{C}$. Previously, nuclear reaction studies almost exclusively determined the literature values of these masses in the Atomic-Mass Evaluation. The TRIGA-TRAP results show deviations on the order of 3--4 standard deviations from the latest published values of the Atomic-Mass Evaluation 2003 for some cases. However, the binding-energy differences that are important for nuclear structure studies have been confirmed and improved. The new masses are dis…