g factor

[paper] Spin and magnetic moment of 23Mg

Spin and magnetic moment of 23Mg

D. Yordanov et al.

doi: 10.1088/1361-6471/aa718b

A negative magnetic moment of 23Mg has been determined by high-resolution laser spectroscopy at CERN-ISOLDE. The absolute value is in agreement with previous measurements by nuclear magnetic resonance while the sign points at high-seniority configurations. The result is consistent with shell-model predictions for nuclei with valence nucleons in the sd shell.

[paper] Onset of deformation in neutron-deficient Bi isotopes studied by laser spectroscopy

Onset of deformation in neutron-deficient Bi isotopes studied by laser spectroscopy

A.E. Barzakh et al.

doi: 10.1103/PhysRevC.95.044324

In-source laser spectroscopy experiments for bismuth isotopes at the 306.77-nm atomic transition has been carried out at the Investigation of Radioactive Isotopes on Synchrocyclotron facility of Petersburg Nuclear Physics Institute. New data on isotope shifts and hyperfine structure for Bi ground states and isomers (189,190m1,190m2,191,192,192m,194,194m,198mBi) have been obtained. The changes in the mean-square charge radii δ⟨r2⟩ and magnetic-moment values have been deduced. For Bi nuclei a marked deviation from the isotopic trend of δ⟨r2⟩ in lead and thallium isotopic chains has been demonstrated at N<111. This has been interpreted as an indication of the onset of quadrupole deformation. Analysis of the magnetic moments for odd-odd Bi isotopes also points to the possible increase in deformation at N<111.

LNS report 2013-14

The Laboratorio Nazionale del Sud (LNS) has just made their Activity Report for 2013-14 available online.

You may download this file (~115 MB) following link

[paper] Relativistic description of second-order correction to nuclear magnetic moments with point-coupling residual interaction

Relativistic description of second-order correction to nuclear magnetic moments with point-coupling residual interaction

Jian Li et al.

doi: 10.1007/s11433-010-4215-7

Using the single particle states and the residual interaction derived from the relativistic point-coupling model with the PC-F1 parameter set, the second-order core polarization corrections to nuclear magnetic moments of LS closed shell nuclei ±1 nucleon with A = 15, 17, 39 and 41 are studied and compared with previous non-relativistic results. It is found that the second-order corrections are significant. With these corrections, the isovector magnetic moments of the concerned nuclei are well reproduced, especially those for A = 17 and A = 41.

[paper] g factors of nuclear low-lying states: A covariant description

g factors of nuclear low-lying states: A covariant description

JangMing Yao et al.

doi: 10.1007/s11433-010-4214-8

The g factors and spectroscopic quadrupole moments of low-lying excited states 2+1 , … , 8+1 in 24Mg are studied in a covariant density functional theory. The wave functions are constructed by configuration mixing of axially deformed mean-field states projected on good angular momentum. The mean-field states are obtained from the constraint relativistic point-coupling model plus BCS calculations using the PC-F1 parametrization for the particle-hole channel and a density-independent delta-force for the particle-particle channel. The available experimental g factor and spectroscopic quadrupole moment of 2+1 state are reproduced quite well. The angular momentum dependence of g factors and spectroscopic quadrupole moments, as well as the effects of pairing correlations are investigated.

[paper] The orbital g-factor and related sum rules

The orbital g-factor and related sum rules

Wolfgang Bentz and Akito Arima

doi: 10.1007/s11433-010-4224-6

The renormalization of the orbital g-factor in nuclei is discussed on the basis of gauge invariance. The relation of the orbital g-factor to the integrated E1 photoabsorption cross section is reviewed, and its relation to the M1 sum rule for the scissors mode of deformed nuclei is examined.

[paper] Sixfold improved single particle measurement of the magnetic moment of the antiproton

Sixfold improved single particle measurement of the magnetic moment of the antiproton

H. Nagahama et al.

doi: 10.1038/ncomms14084

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value g(antiproton)=2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement g(proton)=2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

[paper] Prediction and evaluation of magnetic moments in T=1/2, 3/2, and 5/2 mirror nuclei

Prediction and evaluation of magnetic moments in T=1/2, 3/2, and 5/2 mirror nuclei

Theo J. Mertzimekis

doi: 10.1103/PhysRevC.94.064313

The Buck-Perez analysis of mirror nuclei magnetic moments has been applied on an updated set of data for T=1/2,3/2 mirror pairs and attempted for the first time for T=5/2 nuclei. The spin expectation value for mirror nuclei up to mass A=63 has been reexamined. The main purpose is to test Buck-Perez analysis effectiveness as a prediction and—more importantly—an evaluation tool of magnetic moments in mirror nuclei. In this scheme, ambiguous signs of magnetic moments are resolved, evaluations of moments with multiple existing measurements have been performed, and a set of predicted values for missing moments, especially for several neutron-deficient nuclei is produced. A resolution for the case of the 57Cu ground-state magnetic moment is proposed. Overall, the method seems to be promising for future evaluations and planning future measurements.

1228 isotopes, 5800 entries later

Last Friday, 28.10, was a National Holiday here in Greece, our OXI! day (“No!” day in english), the 76th anniversary of the beginning of WWII in Greece, after Italy’s attack on the NW border with Albania. It is always a nice holiday as kids and grown ups don’t go to school and people grab the opportunty to do something nice, weather permitted, which is more or less the truth since October has been generous with sunlight and medium temperatures the recent years.

For my account, I chose to revisit a favorite land, an exciting land, the land of isotopes. You might know already or have concluded from visiting this page that I maintain a database of nuclear electromagnetic moments, which is rather unique worldwide and has been an integral part of the IAEA Nuclear Data Section for over a year now (this is the moment you should appllaud people!). I spent my OXI break updating the database, which at the beginning of the week seemed easy, but in the end resulted in a very difficult task as I have found several typos, mistakes in the values and losses of format integrity inherited from previous printed compilations. The proofing is a very difficult job and one has to do it carefully at the very beginning, else there is always the risk to transmit -eternally- wrong information. And I wouldn’t like to think I have the wrong value of the proton magnetic moment when I get my next MRI exam…

All in all, the database has now 1228 isotopes spanning a set of 5800 entries of magnetic dipole and electric quadrupole moments. Both numbers are larger if you include the nuclear charge radii that now exist only in the development server together with nuclear masses and X-ray data. This version will be updated fully after the AME2016 will be published, word says some time in this coming December.

Despite the “self-confinement” on a chair inside a room with tons of tea and coffee, my OXI day weekend has been both fruitful and joyous. But next time I will pick a different destination 😉

An update to the nuclear moments database

The nuclear moments database is sponsored and hosted by the IAEA Nuclear Data Section.
See the latest official release here:
http://www-nds.iaea.org/nuclearmoments

This is a major update with cutoff date 30.06.2016. The next is scheduled for 30.09.2016.

On the parallel, on the development server (always on beta status) http://data.magneticmoments.info
a new database is being tested that additionally includes nuclear charge radii and nuclear masses (in fact mass excess values).
This database is currently in sync with the IAEA servers, but will eventually branch out (early next year).

My recommendation is to follow the official releases on IAEA web if you want to use it in a paper (please cite the database using the citations listed in the server). If you can’t wait for the official release, try the development server, where more features are and will be available as the site expands.

Typos, comments or missing values? PLEASE let me know about it (thanks in advance!)
The blog is also there for more resources http://magneticmoments.info/wp