Correct use of the Gordon decomposition in the calculation of nucleon magnetic dipole moments
M. Mekhfi
doi: 10.1103/PhysRevC.78.055205
We perform the calculation of the nucleon dipole magnetic moment in full detail using the Gordon decomposition of the free quark current. This calculation has become necessary because of frequent misuse of the Gordon decomposition by some authors in computing the nucleon dipole magnetic moment.
Quadrupole moments of some nuclei around the mass of A∼80: 76,78,80,82,84Kr and neighboring Se isotope
N. Turkan et al.
doi: 10.1134/S1063778809060088
The quadrupole moments of 76,78,80,82,84,88Kr and 74,76,78,80,82Se isotopes are investigated in terms of the interacting boson model (IBM), and it was found that a good description of them can also be concluded in this model. Before the quadrupole moments were calculated, the positive-parity states and electromagnetic-transition rates (B(E2)) of even-mass Kr nuclei have also been obtained within the framework of IBM. It was seen that there is a good agreement between the presented results and the previous experimental data. The quadrupole moments of the neighboring Se isotopes were also obtained and it was seen that the results are satisfactorily agree well with the previous experimental data.
g factor of the exotic N=21 isotope 34Al: probing the N=20 and N=28 shell gaps at the border of the "island of inversion"
P. Himpe et al.
doi: 10.1016/j.physletb.2007.11.017
For the first time the g factor of an isotope beyond N=20 near the "island of inversion" has been measured. A 34Al radioactive beam was produced in a one-neutron pickup reaction on a 36S primary beam at 77.5 MeV/u, providing a large spin-polarization for application of the β-Nuclear Magnetic Resonance (β-NMR) method. The measured g factor of 34Al, |g|=0.539(2), combined with results from earlier β-decay studies, allows to firmly assign a ground state spin/parity 4−. Comparison to large scale shell model calculations reveals that a dominant amount of intruder components is needed in the 34Al wave function to account for the observed large magnetic moment μ=(+)2.156(16)μN. This reveals Z=13 to be a true "transition number" between the normal Z=14 Si isotopes and the abnormal Z=12 Mg isotopes. The sensitivity of this odd–odd ground state dipole moment to the N=20, as well as the N=28 gap, reveals that both are significantly reduced, despite Z=13 being outside the conventional island of inversion.
Magnetic moments of 3013Al17 and 3213Al19
H. Ueno et al.
doi: 10.1016/j.physletb.2005.04.037
Ground-state magnetic moments of 30Al and 32Al were measured
with the β-NMR method using radioactive-isotope beams spin-polarized in the projectile-fragmentation
reaction. Polarization of sizes |P|=0.5–1% were obtained in spite of the large numbers of nucleons
that are removed from the projectile 40Ar, providing a promising prospect that
substantial polarizations are obtained even in fragment nuclei that are far removed from the projectile nucleus.
The obtained μ moments, |μexp(30Al)|=3.010(7) μN
and |μexp(32Al)|=1.959(9) μN, are in agreement with
shell model calculations within the sd valence space, although a reduction in the energy-gap between
the sd and pf states is predicted for 32Al in recent theoretical studies.