Search results for " DIP"
showing 10 items of 1273 documents
Collinear laser spectroscopy on108g, 108m In using an ion source with bunched beam release
1986
The hyperfine structure and isotope shift of108gIn and108mIn have been investigated by means of collinear fast-beam laser spectroscopy in the resonance line atλ=451 nm. The indium isotopes were prepared at the GSI on-line mass separator following a fusion evaporation reaction. For the first time, a FEBIAD ion source with bunched release of indium was used. Magnetic dipole moments, electric quadrupole moments and isotope shifts were determined. The present results lead us to assign the spinI=2 to the108In (T 1/2=40 min) state. Spins and moments are discussed in the framework of thejj-coupling model.
Magnetic dipole moments near 132Sn: new measurement on 135I by NMR/ON
1998
Abstract On-line low temperature nuclear orientation (OLNO) experiments have been performed on the isotope 135 I using the technique of nuclear magnetic resonance on oriented nuclei (NMR/ON). The magnetic moment of the 7 2 + ground state has been measured to be μ( 7 2 + 135 I ) = 2.940(2) μ N , thereby extending the known data on these states in odd- A I isotopes up to the neutron shell closure at N = 82. Shell-model calculations have been performed for the magnetic moments of 7 2 + states in the N = 82 isotones using free-nucleon and effective g -factors. The effective g -factors are obtained from a perturbation calculation that includes corrections for core polarisation and meson-exchange…
Meson exchange and isobar admixture contributions to elastic electron-deuteron scattering
1974
The deuteron structure functions for elastic electron scattering and the deuteron static properties have been calculated with the inclusion of isobar admixtures to the deuteron wave function and meson exchange currents. At higher momentum transfers the structure functions are increased significantly because of the strong enhancement of the deuteron magnetic dipole form factor. Roughly 15–35% of this enhancement depending on the momentum transfer arise from the meson exchange currents.
Polarizability effects in electronic and muonic atoms
1983
TheS state polarizability shifts are derived from the virtual forward Compton scattering in the unretarded dipole approximation. In the non-relativistic limit ω N /2m≪1, the shift is proportional to the photonuclear sum rule σ−3/2, while in the relativistic limit ω N /2m≫1 it is proportional to a logarithmically weighted σ−2 sum rule. In both cases, the characteristic momentum transfer is (2mω N )1/2. The non-locality from the intermediate lepton propagation removes the divergence typical of the static limit. Explicit formulas for the shifts are given for both the relativistic and non-relativistic limits.
The hadronic light-by-light contribution to the muon's anomalous magnetic moment
2019
In view of the current 3 - 4 $\sigma$ deviation between theoretical and experimental values for the muon's anomalous magnetic moment, we review the ongoing efforts in constraining the hadronic light-by-light contribution to $a_\mu$ by using dispersive techniques combined with a dedicated experimental program to obtain the required hadronic input.
Laser spectroscopy of francium isotopes at the borders of the region of reflection asymmetry
2014
The magnetic dipole moments and changes in mean-square charge radii of the neutron-rich $^{218m,219,229,231}\text{Fr}$ isotopes were measured with the newly-installed Collinear Resonance Ionization Spectroscopy (CRIS) beam line at ISOLDE, CERN, probing the $7s~^{2}S_{1/2}$ to $8p~^{2}P_{3/2}$ atomic transition. The $\delta\langle r^{2}\rangle^{A,221}$ values for $^{218m,219}\text{Fr}$ and $^{229,231}\text{Fr}$ follow the observed increasing slope of the charge radii beyond $N~=~126$. The charge radii odd-even staggering in this neutron-rich region is discussed, showing that $^{220}\text{Fr}$ has a weakly inverted odd-even staggering while $^{228}\text{Fr}$ has normal staggering. This sugges…
The axial isoscalar neutral current from inelastic electron-nuclear scattering
1978
Abstract Parity violating effects due to neutral currents in isoscalar 0+→1+ nuclear transitions induced by electron scattering are enhanced owing to the small isoscalar magnetic dipole strength. A polarization asymmetry of the order 10−4 is expected at q ∼ 100 MeV for the 12C transition to the 1+(T = 0) state at 12.71 MeV. It would allow to single out the (electron vector current) × (hardonic axial isoscalar current) quantum numbers and couplings of the neutral current interaction.
The generalized Gerasimov–Drell–Hearn sum rule for deuteron electrodisintegration
2004
The generalized Gerasimov-Drell-Hearn sum rule $I^{GDH}_{\gamma^*d}(Q^2)$ for deuteron electrodisintegration $d(e,e')np$ as function of the squared four-momentum transfer $Q^2$ is evaluated by explicit integration. The calculation is based on a conventional nonrelativistic framework using a realistic $NN$-potential and including contributions from meson exchange currents, isobar configurations and leading order relativistic terms. Good convergence is achieved. The prominent feature is a deep negative minimum, $I_{\gamma^* d}^{GDH}=-9.5$ mb, at low $Q^2\approx 0.2$ fm$^{-2}$ which is almost exclusively driven by the nucleon isovector anomalous magnetic moment contribution to the magnetic dip…
Nuclear moments and charge radii of argon isotopes between the neutron-shell closures and
2008
We report the measurement of optical isotope shifts for 40−44 Ar relative to 38 Ar from which changes in the mean square nuclear charge radii across the 1f7/2 neutron shell are deduced. In addition, the hyperfine structure of 41 Ar and 43 Ar yields the spins, magnetic dipole and electric quadrupole moments, in particular the spin I = 5/2 for 43 Ar. The investigations were carried out by fast-beam collinear laser spectroscopy using highly sensitive detection based on optical pumping and state-selective collisional ionization. Mean square charge radii are now known from 32 Ar to 46 Ar, covering sd-shell as well as f7/2-shell nuclei. They are discussed in the framework of spherical SGII Skyrme…
Elastic electron deuteron scattering with consistent meson exchange and relativistic contributions of leading order
1999
The influence of relativistic contributions to elastic electron deuteron scattering is studied systematically at low and intermediate momentum transfers ($Q^2\leq 30$ fm$^{-2}$). In a $(p/M)$-expansion, all leading order relativistic $\pi$-exchange contributions consistent with the Bonn OBEPQ models are included. In addition, static heavy meson exchange currents including boost terms and lowest order $\rho\pi\gamma$-currents are considered. Sizeable effects from the various relativistic two-body contributions, mainly from $\pi$-exchange, have been found in form factors, structure functions and the tensor polarization $T_{20}$. Furthermore, static properties, viz. magnetic dipole and charge …