Search results for "Ground state"
showing 10 items of 928 documents
First identification of rotational band structures inRe9175166
2015
Despite that it is more than 100 years since the atomic nucleus was first dis- covered by Ernest Rutherford and coworkers, many of its features still elude our understanding. The fact that the fundamental interactions between the nuclear constituents; nucleons, and ultimately quarks, are not yet known in detail, and the complexity of the nuclear many-body system compound the great challenges facing theoretical interpretations of experimental data. It is therefore important to focus on distinct phenomena where experimental mea- surements can be compared with theoretical predictions, providing stringent tests of theory. One such area is the nuclear phenomenology of collective excitations rela…
Beta decay of very neutron-rich110Mo studied at the new IGISOL facility
1994
The decay of the new activity110Mo (t1/2=0.30(4).s) has been observed at the new IGISOL separator. Multiscaled singles,β-γ-t and γ-y-t coincidences were recorded. The decay scheme suggests Iπ=2+ for the ground state of the daughter nucleus110Tc. Three 1+ levels are fed with logft values below 5, indicating no drastic change among Mo and Ru decays at the middle of the neutron shell. This experiment confirms the expectation that the new IGISOL facility will allow the identification of one or two new more neutron-rich isotopes per element in this region.
Systematic investigation of the drip-line nuclei 11Li and 14Be and their unbound subsystems 10Li and 13Be
2007
Fragmentation reactions in a carbon target with beams of 11Li and 14Be at relativistic energies have been studied in a kinematically complete experiment at the ALADIN-LAND setup at GSI. Excited states in 11Li and 14Be were obtained from the data in the inelastic channel. The measured cross sections with the core nucleus in the final state show that in the 14Be case core polarization plays an important role. In the one-neutron knockout channels the measured angular correlations between fragment and neutron are asymmetric, which demonstrates the presence of states with different parities in the 11Li and 14Be ground states. For 10Li a low-lying virtual s-state, a p-state and evidence for a d-s…
Electromagnetic nucleon form factors in the spacelike region
1997
Abstract Form factors for elastic electron scattering parametrise the collective response of a struck object and provide information vital for the understanding of its ground state. The quality of existing data for the neutron is much behind that for the proton; it will now benefit from coincidence experiments at modern cw accelerators. For the electric form factor the scattering of high energy polarised electrons from polarised targets or the spin transfer to the recoiling neutron from unpolarised targets now exhibits its full potential in running experiments and delivers first results.
Description of the two-neutrino ββ decay of100Mo by pnMAVA
2009
The microscopic anharmonic vibrator approach (MAVA) is a scheme where the one- and two-phonon states of an even–even nucleus are treated consistently by using a realistic microscopic nuclear Hamiltonian. This model has recently been extended to describe odd–odd nuclei by adding proton–neutron phonons in a scheme called the proton–neutron MAVA (pnMAVA). In this paper, we apply pnMAVA to compute the nuclear matrix elements corresponding to the two-neutrino double beta (2νββ) decay of 100Mo to the ground state and the first excited 0+ state of 100Ru in a realistic single-particle space. We also compute the GT− and GT+ Gamow–Teller strength functions and compare them with the plain pnQRPA (prot…
Nuclear ground state properties: Recent results and prospects at isolde
1985
The application of lasers to nuclear physics is an extremely lively and Interesting area of research in physics. In the few years that have passed since its development, a large number of beautiful experiments have been performed. Most of the experiments have been performed at ISOLDE. For the next years, optical spectroscopy will continue to play a key role for a determination of spins, moments and charge radll of nuclear ground or isomeric states.
On the nuclear structure of 229Ra
1992
14 pages, 3 tables, 6 figures.
Energy Dependence of Collective Flow of Neutrons and Charged Particles in 197AU + 197AU Collisions
1994
Collective flow of nuclear matter is one important aspect of the research performed at heavy ion accelerator laboratories. The phenomenon was predicted on the basis of hydrodynamical calculations [1], and experimental evidence was first presented for the systems 93 Nb + 93 Nb and 197 Au + 197 Au in the projectile energy range between 150 and 1050 MeV/u [2]. The comparison to microscopic calculations shows that nuclear matter is compressed to about two to three times the ground state density and that a substantial fraction of the kinetic energy in the entrance channel is converted into compressional energy [3]. In these calculations, the relation between density and compressional energy depe…
Measurement of the Be7(n,p) cross section at thermal energy
2019
The Be7(n,p) cross section was measured with an ion-implanted Be7 target at a thermal neutron beam of the research reactor LVR-15 in Řež. The cross section to the ground state of Li7 is σ(n,p0)=43800±1400b and the cross section to the first excited state of Li7 is σ(n,p1)=520±260b.
Precision Spectroscopy on Trapped Radioactive Ions: Ground-State Hyperfine Splittings of 133 Ba + and 131 Ba +
1987
The ground-state hyperfine splitting of radioactive Ba+ isotopes of mass 133 and 131, confined in a r.f. quadrupole trap, has been measured by laser-microwave double resonances. The results are Δν(133) = 9 925 453 554.59(10) Hz and Δν(131) = 9 107 913 698.97 (50) Hz. The experiment, including measurements of systematic shifts, was performed on quantities of about 1012 isotopes, produced by nuclear reactions and collected at the ISOLDE facility at CERN. The precision is comparable to equivalent measurements on stable isotopes and demonstrates the high-sensitivity of the stored-ion technique. The experiment can be regarded as a first step to a systematic precision study of hyperfine anomalies…