Search results for "Hyperfine structure"

Nuclear Ground-State Properties from Laser and Mass Spectroscopy

1990

Atomic physics played an important role in establishing our present-day knowledge on the atomic nucleus. Especially mass spectrometry and optical spectroscopy were the main sources of information on nuclear properties in the early days of nuclear physics. Still now, precise information on nuclear masses (or binding energies) are obtained by mass spectrometry whereas mass differences between two isotopes are usually determined by nuclear-spectroscopy techniques via a determination of the Q-value of nuclear reactions or decay. Almost all our information on the nuclear spins I, the nuclear magnetic dipole moment μ I, the spectroscopic quadrupole moment Q, and the changes in the mean-square cha…

Precision Spectroscopy on Trapped Radioactive Ions: Ground-State Hyperfine Splittings of 133 Ba + and 131 Ba +

1987

The ground-state hyperfine splitting of radioactive Ba+ isotopes of mass 133 and 131, confined in a r.f. quadrupole trap, has been measured by laser-microwave double resonances. The results are Δν(133) = 9 925 453 554.59(10) Hz and Δν(131) = 9 107 913 698.97 (50) Hz. The experiment, including measurements of systematic shifts, was performed on quantities of about 1012 isotopes, produced by nuclear reactions and collected at the ISOLDE facility at CERN. The precision is comparable to equivalent measurements on stable isotopes and demonstrates the high-sensitivity of the stored-ion technique. The experiment can be regarded as a first step to a systematic precision study of hyperfine anomalies…

Concluding remarks application of lasers to nuclear physics

1985

Neutral currents in atomic and nuclear physics

1990

Abstract The spin structure function of the proton measured by the EMC collaboration suggests an axial isoscalar neutral current for the nucleon. I study its implications for neutral current phenomena in atomic and nuclear physics. This includes parity-violating observables for transitions between hyperfine multiplets in light muonic atoms, selected inelastic neutrino nuclear reactions and the polarization asymmetry in electron scattering for isoscalar transitions. The neutrino-induced process 7 Li → 7 Li ∗ (0.478 MeV ) is particularly favourable for neutrino reactor experiments. I find that the axial isoscalar coupling extracted from the EMC measurement increases the neutrino cross section…

Determination of nuclear spins of short-lived Rb and Cs isotopes by β radiation detected optical pumping

1978

Precision measurement of spin-dependent interaction strengths for spin-1 and spin-2 87Rb atoms

2006

We report on precision measurements of spin-dependent interaction-strengths in the 87Rb spin-1 and spin-2 hyperfine ground states. Our method is based on the recent observation of coherence in the collisionally driven spin-dynamics of ultracold atom pairs trapped in optical lattices. Analysis of the Rabi-type oscillations between two spin states of an atom pair allows a direct determination of the coupling parameters in the interaction hamiltonian. We deduce differences in scattering lengths from our data that can directly be compared to theoretical predictions in order to test interatomic potentials. Our measurements agree with the predictions within 20%. The knowledge of these coupling pa…

Nuclear ground state properties of 99Sr by collinear laser spectroscopy with non-optical detection

1991

Abstract Collinear fast-beam laser spectroscopy, with improved sensitivity for ions with hyperfine split transitions, is performed to measure the hyperfine structure and the isotope shift of the well deformed short-lived 99Sr. The new method consists in ground state depopulation by a two-step optical pumping sequence prior to state selective neutralization and fast-atom counting. A definitive nuclear spin value I = 3 2 , the change in mean square charge radius δ〈r2〉98,99 and the nuclear moments are derived. These results are compared to nuclear spectroscopy information and are interpreted in the frame of the particle plus deformed core model.

Spins, moments and charge radii in the isotopic series181Hg-191Hg

1976

The hyperfine structure splitting and the isotope shift in the (6 s2 1S0 - 6s 6p3P1,λ=2,537 A) line of very neutron deficient Hg isotopes were determined by the β radiation detected optical pumping method (β-RADOP). In addition, nuclear magnetic resonance was observed in the atomic ground state. The results are Mean-square nuclear charge radii are calculated. Interpreting the sudden change of nuclear radius between187Hg and185Hg δ〈r2〉187,185=0.42(5)fm2 as oblate-prolate shape transition, one obtains δ〈β2〉 =0.054(5).

Precision Test of Many-Body QED in theBe+2pFine Structure Doublet Using Short-Lived Isotopes

2015

Absolute transition frequencies of the $2s\text{ }{^{2}S}_{1/2}\ensuremath{\rightarrow}2p\text{ }{^{2}P}_{1/2,3/2}$ transitions in ${\mathrm{Be}}^{+}$ were measured for the isotopes $^{7,9--12}\mathrm{Be}$. The fine structure splitting of the $2p$ state and its isotope dependence are extracted and compared to results of ab initio calculations using explicitly correlated basis functions, including relativistic and quantum electrodynamics effects at the order of $m{\ensuremath{\alpha}}^{6}$ and $m{\ensuremath{\alpha}}^{7} \mathrm{ln} \ensuremath{\alpha}$. Accuracy has been improved in both the theory and experiment by 2 orders of magnitude, and good agreement is observed. This represents on…

Relativistic corrections to the Drell-Hearn-Gerasimov sum rule in the constitutent quark model

1994

Relativistic corrections have been calculated for the Drell-Hearn-Gerasimov sum rule in the framework of the constituent-quark model. These corrections lead to additional absorption strength due to relativistic dipole currents in the case of a hyperfine interaction. The introduction of anomalous magnetic moments requires a subtraction of the dispersion integral at infinity. The additional effects of such anomalous moments, however, are numerically very small within the model.