We study the
ββ decays of
76Ge,
82Se,
136Xe,
124Sn,
128Te,
130Te in the shell model framework. Bounds on the neutrino mass are obtained and it is found that, among them,
82Se and
124Sn are the most ...favoured isotopes to detect the neutrinoless mode.
.
In this article, we analyze some nuclear-structure aspects of the 0ν double-beta decay nuclear matrix elements (NME). We give results for the decays of
48
Ca ,
76
Ge ,
82
Se ,
124
Sn ,
128
Te ,
130
...Te , and
136
Xe , using improved effective interactions and valence spaces. We examine the dependence of the NMEs on the effective interaction and the valence space, and analyze the effects of the short-range correlations and the finite size of the nucleon. Finally, we study the influence of the deformation on the values of the NMEs.
In the level schemes of sd shell nuclei, there is generally at relatively low excitation energies, coexistence of normal 0
ℏω positive parity states and of intruder 1
ℏω negative parity states. The ...aim of the present work is to describe these intruder states in the full p–sd–pf model space with a
4He core allowing one nucleon jump between the major shells. To construct our PSDPF interaction, we first modified the p–sd and sd–pf cross-monopole terms and then applied a fitting procedure to adjust all PSDPF parameters by comparing an extended set of experimental and calculated excitation energies. Results obtained with the new interaction have been finally compared with experimental data for nuclei throughout the sd shell.
New poly(
p-phenylenevinylene) (PPV)-type conducting polymers containing different concentrations of thiophene and fluorene functional units were investigated in this work and the photophysical and ...electrochemical properties were evaluated. We observed a dependence of these properties on the concentration of thiophene units in the polymer backbone. The hole mobilities were estimated to be on the order of 10
−6
cm
2
V
−1
s
−1. The polymers were combined with different concentrations of a soluble fullerene derivative (PCBM) and applied in bulk-heterojunction photovoltaic cells. The effects of PCBM concentration and of annealing (post-production treatment) on these devices were investigated. The best results were obtained for the materials containing higher concentrations of thiophene units.
The shell structure of atomic nuclei is associated with 'magic numbers' and originates in the nearly independent motion of neutrons and protons in a mean potential generated by all nucleons. During ...b1-decay, a proton transforms into a neutron in a previously not fully occupied orbital, emitting a positron-neutrino pair with either parallel or antiparallel spins, in a Gamow-Teller or Fermi transition, respectively. The transition probability, or strength, of a Gamow-Teller transition depends sensitively on the underlying shell structure and is usually distributed among many states in the neighbouring nucleus. Here we report measurements of the half-life and decay energy for the decay of 100Sn, the heaviest doubly magic nucleus with equal numbers of protons and neutrons. In the b-decay of 100Sn, a large fraction of the strength is observable because of the large decay energy. We determine the largest Gamow-Teller strength so far measured in allowed nuclear b-decay, establishing the 'superallowed' nature of this Gamow-Teller transition. The large strength and the low-energy states in the daughter nucleus, 100In, are well reproduced by modern, large-scale shell model calculations.
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