Search results for "Orbital"
showing 10 items of 679 documents
Shell structure of potassium isotopes deduced from their magnetic moments
2014
\item[Background] Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \item[Purpose] Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \item[Method] High-resolution collinear laser spectroscopy on bunched atomic beams. \item[Results] From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the …
Effect of higher orbital angular momenta in the baryon spectrum
2001
We have performed a Faddeev calculation of the baryon spectrum for the chiral constituent quark model including higher orbital angular momentum states. We have found that the effect of these states is important, although a description of the baryon spectrum of the same quality as the one given by including only the lowest-order configurations can be obtained. We have studied the effect of the pseudoscalar quark-quark interaction on the relative position of the positive- and negative-parity excitations of the nucleon as well as the effect of varying the strength of the color-magnetic interaction.
Coherent pion production induced by protons and light ions
1995
Abstract We study coherent pion production by means of the (p,n) and (He,t) reactions on different nuclei and at different energies of the projectile. Energy and angular distributions are calculated. The angular distributions are rather narrow along the direction of the momentum transfer, particularly in heavy nuclei. The reaction is sensitive to the longitudinal part of the elementary NN→NΔ interaction. It also provides a new tool to obtain information on the pion-nuclear interaction, complementary to that offered by reactions with real pions.
Identification of excited states in119Ba
2000
Excited states have been identified in the very neutron-deficient ${}^{119}\mathrm{Ba}$ nucleus. Two bands have been observed, which are likely to be based on ${h}_{11/2}$ and ${(g}_{7/2}{d}_{5/2})$ neutron orbitals. Despite this being the first observation of excited states in ${}^{119}\mathrm{Ba},$ the bands extend to $(75/2)\ensuremath{\Elzxh}$ and $(79/2)\ensuremath{\Elzxh},$ respectively. The bands have been assigned to ${}^{119}\mathrm{Ba}$ using gamma-recoil and gamma--x-ray coincidences. Several quasiparticle alignments have been identified, involving neutron ${(h}_{11/2}{)}^{2}$ and proton ${(h}_{11/2}{)}^{2}$ aligned configurations. Furthermore, the bands show features which are r…
Magnetic hyperfine anomaly in muonic193Ir
1977
The nuclear decay of the 5/2+ 139 keV state to the 3/2+ ground state was observed in muonic193Ir. The hyperfine splitting of the 3/2+ state and 5/2+ state was determined to be 640±100 eV and 1280±160 eV, respectively. The ground state splitting is about twice that of a point nucleus, an anomaly never observed this large. This is mainly due to the different radial distribution of spin and orbital magnetization of a d3/2 proton configuration for which these contributions nearly cancel to zero in the magnetic moment. But calculations including configuration mixing and coupling to a vibrating or a deformed core show deviations. The groundstate anomaly is in line with that observed by the Mossba…
Nuclear stucture studies of transfermium nuclei
2007
The study of deformed nuclei in the region of 254No provides an indirect method to access the single-particle orbitals which are of relevance in determining the location of the next closed proton and neutron closed shells above 208Pb. Several of these orbitals are strongly down-sloping and are close to the Fermi surface in the deformed region. These nuclei are some of the heaviest for which detailed spectroscopy can be performed. Initial in-beam measurements in the region focussed on γ-ray spectroscopy of even-even nuclei (e.g. 252,254No, 250Fm), while more recently attention has switched to odd-mass nuclei such as 253No, 251Md and 255Lr, the latter being the heaviest nucleus so far studied…
The discovery of the serendipitous X-ray pulsar SAX J1802.7–2017 from a BeppoSAX observation of GX 9+1
2004
Abstract We have discovered a new X-ray source, SAX J1802.7–2017, ∼22′ away from the bright X-ray source GX 9+1, during a BeppoSAX observation of this latter one on 2001 September 16-20. The count rate of SAX J1802.7–2017 is comparable to the background (∼0.04 c/s) during the first 50 ks of the observation, then the count rate shows a large variability increasing up to ∼0.28 c/s. We have performed a temporal analysis finding that SAX J1802.7–2017 has a pulse period of ∼139.61 s, a projected orbital separation a x sin i of 48±5 lt-s and an orbital period of 3.7 +0.4 −0.2 days, allowing to classify the new object as an X-ray pulsar.
Spectroscopy on the proton drip-line: Probing the structure dependence of isospin nonconserving interactions
2014
J. Henderson et al. ; 4 pags. ; 4 figs. ; PACS number(s): 21.10.Re, 21.60.Cs, 23.20.Lv, 27.50.+e
The Proton-Neutron Interaction in Neutron-Rich A ≃ 100 Nuclei
1988
The possible factors responsible for the sudden onset of nuclear deformation in neutron-rich A≅100 nuclei are reviewed from the systematics of subshell occupation numbers for neutron and proton orbitals. The agreement between our results from a Nilsson model with existing selfconsistent HFB calculations strengthens the role of a cumulative neutron-proton interaction, but does not substantiate the conjecture concerning a selective involvement of the πg9/2-νg7/2 spin-orbit-partner orbitals in producing deformation as das suggested in earlier work.
High-momentum components in the 1p orbitals of 16O
1995
Abstract We have investigated that part of the proton momentum distribution of 16O that is linked through the (e, e′p) reaction to low-lying discrete states in 15N. The MAMI facility with its new generation of 100%-duty-cycle electron accelerator has allowed to cover in this experiment the previously not accessible momentum range of 265