Search results for "force"
showing 10 items of 3423 documents
Neutrinoless double beta decays of 106Cd revisited
2011
Abstract Neutrinoless double beta ( 0 ν 2 β ) decays of 106 Cd are studied for the transitions to the ground state, 0 gs + , and 0 + excited states in 106 Pd by using realistic many-body wave functions calculated in the framework of the quasiparticle random-phase approximation and its extensions. Effective, G-matrix-based nuclear forces are used in large single-particle model spaces. Both the β + β + and β + EC channels of the 0 ν 2 β decay are discussed and half-lives are computed. Particular attention is devoted to the study of the detectability of the resonant neutrinoless double electron capture ( R 0 ν ECEC ) process in 106 Cd. The calculations of the present article constitute the thu…
Momentum partition between constituents of exotic atoms during laser-induced tunneling ionization
2015
The tunneling ionization of exotic atoms such as muonic hydrogen, muonium, and positronium in a strong laser field of circular polarization is investigated, taking into account the impact of the motion of the center of mass on the the tunneling ionization dynamics. The momentum partition between the ionization products is deduced. The effect of the center-of-mass motion for the momentum distribution of the ionization components is determined. The effect scales with the ratio of the electron (muon) to the atomic core masses and is nonnegligible for exotic atoms, while being insignificant for common atoms. It is shown that the electron (muon) momentum shift during the under-the-barrier motion…
GAP solitons in 1D asymmetric physical systems
2008
We present a general approach for studying the nonlinear transmittance and gap solitons characteristics of asymmetric and one dimensional (1 D) systems in the low amplitude or Nonlinear Schrodinger limit. Included in this approach are some novel results on naturally asymmetric systems and systems where the symmetry is broken by an external constant force.
Enhanced nuclear Schiff moment in stable and metastable nuclei
2019
Nuclei with static intrinsic octupole deformation or a soft octupole vibrational mode lead to strongly enhanced collective nuclear Schiff? moments. Interaction between electrons and these Schiff moments produce enhanced time reversal (T) and parity (P) violating electric dipole moments (EDM) in atoms and molecules. Corresponding experiments may be used to test CP-violation theories predicting T,P-violating nuclear forces and to search for axions. Nuclear octupole deformations are predicted in many short lived isotopes. This paper investigates octupole deformations in stable and very long lifetime nuclei such as 153Eu, 235U, 237Np and 227Ac, which can ease atomic experiments substantially. T…
Translationally invariant treatment of pair correlations in nuclei - II. Tensor correlations
1998
We study the extension of our translationally invariant treatment of few-body nuclear systems to include tensor forces and correlations. It is shown that a direct application of our method is not as successful for realistic V6 interactions as our previous results for V4 potentials suggested. We investigate the cause in detail for the case of $^4$He, and show that a combination of our method with that of Jastrow-correlated wave functions seems to be a lot more powerful, thereby suggesting that for mildly to strongly repulsive forces such a hybrid procedure may be an appropriate description.
Effects of orbital occupancies and spin–orbit partners on -decay rates
2010
Abstract Neutrinoless double beta ( 0 ν β β ) decay of the 76Ge, 82Se, 128Te, 130Te and 136Xe nuclei is discussed in terms of the associated nuclear matrix element (NME). The effects of the size of the single-particle model space and the occupancies of individual orbits on the NME are discussed by using the proton–neutron quasiparticle random-phase approximation (pnQRPA) with effective, G-matrix-derived nuclear forces. It is found that only in some cases the orbital occupancies play a decisive role for the size of the NME, whereas the inclusion of all the spin–orbit partners is essential to achieve a NME of reasonable quality. The obtained results are compared with published results of othe…
New experimental stopping power data of 4He, 16O, 40Ar, 48Ca and 84Kr projectiles in different solid materials
2018
Abstract New experimental data on energy loss of 4 He, 16 O, 40 Ar, 48 Ca and 84 Kr ions in thin, self-supporting foils of C, Al, Ni, Ag, Lu, Au, Pb and Th are presented. The measurements, using the TOF-E method, were done in a very broad energy range around the stopping power maximum; typically from 0.1 to 11 MeV/u. When available, the extracted stopping power values are compared with the previously published data. The overall agreement is good although a fair comparison is difficult as the covered energy range is much larger than in previous measurements. The small error bars and a broad coverage allowed us to test the predictions of theoretical codes: PASS, CasP, and semi-empirical progr…
NUCLEAR-STRUCTURE EFFECTS ON DOUBLE BETA DECAYS TO 0+ STATES IN 76Ge
2011
Neutrinoless double beta (0νββ) decay of 76 Ge to the ground state and first excited 0+ state in 76 Se is discussed in terms of the associated nuclear matrix elements. The effects arizing from the size of the single-particle model space and the occupancies of the individual orbits are discussed in the framework of the (higher) quasiparticle random-phase approximation with effective, G -matrix-derived nuclear forces. It is found that the orbital occupancies play a role for the size of the nuclear matrix element. Contrary to the ground-state transition the transition to the first excited 0+ state does not depend sensitively on the size of the model space.
Effects of orbital occupancies and spin–orbit partners II: decays of 76Ge, 82Se and 136Xe to first excited states
2011
Abstract The neutrinoless double beta ( 0 ν β β ) decays of 76Ge, 82Se and 136Xe to the first excited 0 + states ( 0 1 + ) in 76Se, 82Kr and 136Ba are studied in calculations using different sizes of the single-particle model spaces and different occupancies of the individual orbits. This is a continuation of a similar study [J. Suhonen, O. Civitarese, Effects of orbital occupancies and spin–orbit partners on 0 ν β β -decay rates, Nucl. Phys. A 847 (2010) 207–232] of the 0 ν β β decays of 76Ge, 82Se, 128Te, 130Te and 136Xe to the ground states of 76Se, 82Kr, 128Xe, 130Xe and 136Ba. The nuclear matrix elements and half-lives of the decays to the 0 1 + states are calculated by the use of the …
Neutron Fermi liquids under the presence of a strong magnetic field with effective nuclear forces
2009
Landau's Fermi liquid parameters are calculated for non-superfluid pure neutron matter in the presence of a strong magnetic field at zero temperature. The particle-hole interactions in the system, where a net magnetization may be present, are characterized by these parameters in the framework of a multipolar formalism. We use either zero- or finite-range effective nuclear forces to describe the nuclear interaction. Using the obtained Fermi liquid parameters, the contribution of a strong magnetic field on some bulk magnitudes such as isothermal compressibility and spin susceptibility is also investigated.