Theo

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.

[db update] delay

Dear friends and colleagues,

just a short note to let you know that the delay in releasing the scheduled update of the nuclear moments database is due to backend technical problems.
Next target date is 31.01.2017. I apologize for the inconvenience.

As always, if you have spotted something missing from the DB, please let me know asap. I can be reached by email.

Regards, Theo

[paper] Addenda to general spin precession and betatron oscillation in storage ring

Addenda to general spin precession and betatron oscillation in storage ring

T. Fukuyama

doi: 10.1142/S0217732317910011

We give the generalized expression of spin precession of extended bunch particles having both anomalous magnetic and electric dipole moments (EDMs) in storage ring in higher order than the previous work and in the presence of E field as well as B field. These addenda are essential since some experiments consider the focusing field in the second-order of the beam extent and in the presence of both B and E fields.

[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] Hyperfine fields in the BaFe2As2 family and their relation to the magnetic moment

Hyperfine fields in the BaFe2As2 family and their relation to the magnetic moment

G. Derondeau et al.

doi: 10.1103/PhysRevB.94.214508

The hyperfine field Bhf and the magnetic properties of the BaFe2As2 family are studied using the fully relativistic Dirac formalism for different types of substitution. The study covers electron doped Ba(Fe1−xCox)2As2 and Ba(Fe1−xNix)2As2, hole doped (Ba1−xKx)Fe2As2, and also isovalently doped Ba(Fe1−xRux)2As2 and BaFe2(As1−xPx)2 for a wide range of the concentration x. For the substituted compounds the hyperfine fields show a very strong dependence on the dopant type and its concentration x. Relativistic contributions were found to have a significantly stronger impact for the iron pnictides when compared to bulk Fe. As an important finding, we demonstrate that it is not sensible to relate the hyperfine field Bhf to the average magnetic moment μ of the compound, as it was done in earlier literature.

[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.