Nuclear Moments

Neugart, R.; Neyens, G.

doi:10.1007/3-540-33787-3_4

Cited by 39 publications

(48 citation statements)

References 112 publications

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“…spin. This proton particle configuration explains the negative sign for the 75,77 Ga quadrupole moments [1,23,24]. In 79 Ga, which also has a g.s.…”

Section: Disucssionmentioning

confidence: 89%

Ground-state spins and moments of72,74,76,78Ga nuclei

et al. 2011

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Laser spectroscopy was performed on the 72,74,76,78 Ga isotopes at On-Line Isotope Mass Separator (ISOLDE) facility, CERN. Ground-state nuclear spins and moments were extracted from the measured hyperfine spectra. The results are compared to shell-model calculations, which provide a detailed probe of the nuclear wave function. The spin is established from the shape of the hyperfine structure and the parity inferred from a comparison of shell-model calculations with the measured nuclear moments. The ground states of 76,78 Ga are both assigned a spin and parity of I π = 2 − , while 74 Ga is tentatively assigned as I π = 3 − . For 72 Ga, the results are consistent with the previous I = 3 assignment.

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“…spin. This proton particle configuration explains the negative sign for the 75,77 Ga quadrupole moments [1,23,24]. In 79 Ga, which also has a g.s.…”

Section: Disucssionmentioning

confidence: 89%

Ground-state spins and moments of72,74,76,78Ga nuclei

et al. 2011

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“…The frequency ν rf of an additionally applied radio-frequency (rf) magnetic field is scanned over the resonances between adjacent m I quantum states. Whenever ν rf matches one of the transition frequencies, a reduction of the spin polarization shows up as a drop in the β-decay asymmetry [14]. The resonances are equidistant and symmetric with respect to the Larmor frequency ν L , with the spacing given by…”

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confidence: 98%

Precision Measurement ofLi11Moments: Influence of Halo Neutrons on theLi9Core

et al. 2008

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The electric quadrupole moment and the magnetic moment of the 11 Li halo nucleus have been measured with more than an order of magnitude higher precision than before, |Q| = 33.3(5) mb and µ = 3.6712(3) µN , revealing a 8.8(1.5)% increase of the quadrupole moment relative to that of 9 Li. This result is compared to various models that aim at describing the halo properties. In the shell model an increased quadrupole moment points to a significant occupation of the 1d orbits, whereas in a simple halo picture this can be explained by relating the quadrupole moments of the proton distribution to the charge radii. Advanced models so far fail to reproduce simultaneously the trends observed in the radii and quadrupole moments of the lithium isotopes.PACS numbers: 21.10. Ky, 27.30.+t, 21.60.Cs Since nuclear physicists could produce and investigate bound systems of nucleons in many possible combinations, a wealth of isotopes with unexpected properties have been discovered. For example, some neutron-rich isotopes of light elements, such as 11 Li, were found to have exceptionally large radii [1]. Upon discovery in 1985, this phenomenon was attributed to either large deformation or to a long tail in the matter distribution [2]. Deformation was soon excluded by the spin and magnetic moment of 11 Li belonging to a spherical πp 3/2 state [3]. Considering the weak binding of the last two neutrons [4], one could conclude that such a nuclear system consists of a core with two loosely bound neutrons around it [5]. This is the concept of 'halo' nuclei which has been related to similar phenomena in atomic and molecular physics [6], showing the universality of the concept. To fully unravel the mechanisms leading to the existence of halo nuclei, many types of experiments have been devoted to the investigation of their properties. An observable that gives information on the nuclear charge deformation is the spectroscopic quadrupole moment. By comparing the quadrupole moment of 11 Li to that of 9 Li, one can investigate how the two halo neutrons modify the deformation of the core which contains the three protons. Already fifteen years ago, a first attempt to do so giving Q( 11 Li)/Q( 9 Li) = 1.14(16), suggested just a slight increase in agreement with the halo concept [7]. Unbiasedly, for a nucleus with a neutron magic number of N = 8 one would expect a minimum value of the quadrupole such as for 13 B [8]. If 11 Li has a larger quadrupole moment than 9 Li, it can not be considered as semi-magic, and the two halo neutrons have to be responsible for an expansion or polarization of the proton distribution in the core. The latter, in terms of the shell model, must be understood by an excitation of halo neutrons to the 1d orbits, and a precise value of the 11 Li quadrupole moment may provide evidence for this. The effect of a more extended charge distribution can be estimated on the basis of a recent laser spectroscopy measurement of the charge radius [9]. The increase of the charge radius for 11 Li, as well as other properties of Li isoto...

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“…It is virtually impossible to show a representative choice of experimental approaches [7] and results [8]. Spins provide basic information for the classification of nuclei, while magnetic moments serve as a probe of the nuclear wave functions within a particular model.…”

Section: Nuclide Production and Laser Spectroscopymentioning

confidence: 99%

“…Relativistic formulas then yield the rest-frame atomic transition frequency ν 0 = √ -ν c ν α . In this way the absolute transition frequencies as well as the isotope shifts for 7 Be to 12 Be were measured to about 0.1 MHz [10]. The determination of radii changes from the total isotope shifts then depends on accurate mass shift calculations for the atomic 3-electron system of Be+ [11].…”

Section: About the Authormentioning

confidence: 99%

Properties of nuclei probed by laser light

Neugart

2017

Europhysics News

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FEATURES 12E arly in the past century it was discovered that basic properties of nuclei influence the atomic spectra. Energy levels of atoms with an odd number of protons or neutrons exhibit hyperfine structure [1]. This was found to arise from a nuclear magnetic moment interacting with the magnetic field produced by the shell electrons. The magnetic moment is associated with a characteristic angular momentum quantum number, called nuclear spin. Both these quantities characterize a nucleus and are related to the orbital of an unpaired nucleon. PROPERTIES OF NUCLEI PROBED BY LASER LIGHT

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Nuclear Moments

Cited by 39 publications

References 112 publications

Ground-state spins and moments of72,74,76,78Ga nuclei

Ground-state spins and moments of72,74,76,78Ga nuclei

Precision Measurement ofLi11Moments: Influence of Halo Neutrons on theLi9Core

Properties of nuclei probed by laser light

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