Search results for "MAGNETIC DIPOLE"
showing 10 items of 217 documents
Study of the discovery potential for hidden photon emission at future electron scattering fixed target experiments
2013
Electron scattering fixed target experiments are a versatile tool to explore various physics phenomena. Recently these experiments came into focus to search for $U(1)$ extensions of the Standard Model of particle physics at low energies. These extensions are motivated from anomalies in astrophysical observations as well as from deviations from Standard Model predictions, such as the discrepancy between the experimental and theoretical determination of the anomalous magnetic moment of the muon. They also arise naturally when the Standard Model is embedded into a more general theory. In the considered $U(1)$ extensions a new, light messenger particle $\gamma^\prime$, the hidden photon, couple…
Searching for new physics in leptonic decays of bottomonium
2002
New Physics can show up in various well-known processes already studied in the Standard Model, in particular by modifying decay rates to some extent. In this work, I examine leptonic decays of $\Upsilon$ vector resonances of bottomonium below $B\bar{B}$ production, subsequent to a magnetic dipole radiative structural transition of the vector resonance yielding a pseudoscalar continuum state, searching for the existence of a light Higgs-like neutral boson that would imply a slight but experimentally measurable breaking of lepton universality.
Nuclear moments of neon isotopes in the range fromNe17at the proton drip line to neutron-richNe25
2005
Nuclear moments of odd-A neon isotopes in the range 17 ≤ A ≤ 25 have been determined from optical hyperfine structures measured by collinear fast-beam laser spectroscopy. The magnetic dipole moments of 17 Ne, 23 Ne and 25 Ne, as well as the electric quadrupole moment of 23 Ne are either reported for the first time or improved considerably. The measurements also decide for a 1/2 + ground state of 25 Ne. The behavior of the magnetic moments of the proton drip-line nucleus 17 Ne and its mirror partner 17 N suggests isospin symmetry. Thus, no clear indication of an anomalous nuclear structure is found for 17 Ne. The magnetic moments of the investigated nuclei are discussed in a shell-model appr…
Spectroscopy ofAt201including the observation of a shears band and the29/2+isomeric state
2015
The excited states of $^{201}\mathrm{At}$ were studied and an isomeric $29/{2}^{+}$ state $[{T}_{\textonehalf{}}=3.39(9)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}]$ was identified by using a fusion-evaporation reaction, a gas-filled recoil separator, and recoil gating techniques. The $29/{2}^{+}$ state is suggested to originate from the $\ensuremath{\pi}({h}_{9/2})\ensuremath{\bigotimes}|^{200}\mathrm{Po};{11}^{\ensuremath{-}}\ensuremath{\rangle}$ configuration, and it decays through the 269- and 339-keV $E2$- and $E3$-type transitions, respectively. Moreover, a cascade of magnetic dipole transitions that is suggested to originate from a shears band was observed by using recoil-…
Nuclear spins, moments and charge radii of108?111Sn
1987
The hyperfine structure splittings (hfs) and isotope shifts (IS) in the atomic transitions 5s2 5p21S0 → 5s2 5p6s1,3P1 have been measured for the radioactive isotopes108−111Sn and all stable ones. The tin isotopes were prepared as fast atomic beams for collinear laser spectroscopy at the GSI online mass separator following a fusion reaction. Nuclear spins, magnetic dipole, electric quadrupole moments and changes in mean square charge radii have been determined. In109Sn the spinI=5/2 was measured for the nuclear ground state (T1/2=18 min) in contradiction to the literature value. The mean square charge radii show a parabolic behaviour with a maximum at N=66. This is interpreted by collective …
Nuclear spins, moments, and changes of the mean square charge radii of sup.(140-153)Eu
1985
The hyperfine structures and isotope shifts of 14 isotopes of Eu (Z=63) in the mass range 140≦A≦153, partly with isomeric states, have been measured in the atomic transitions at 4,594 A and 4,627 A, using the technique of collinear fast-beam laser spectroscopy at the ISOLDE facility at CERN. The nuclear spins, the magnetic dipole and electric quadrupole moments, and the changes in the mean square charge radii have been evaluated. These nuclear parameters clearly reflect the effects of theN=82 neutron-shell closure in the single-proton hole states with respect to the semi-magic gadolinium (Z=64), and theN=88−90 shape transition.
Continuous Stern–Gerlach effect and the magnetic moment of the antiproton
2004
Abstract The measurement of the magnetic moment (or g-factor ) of the antiproton and of the proton is a sensitive test of CPT invariance. We discuss the possibility of applying the continuous Stern–Gerlach effect to detect quantum jumps between the two spin states (spin up and spin down) of the antiproton. The measurement will be performed on a single antiproton stored in a Penning trap. The g -factor of the antiproton is determined by measuring its cyclotron frequency and its spin precession frequency in the magnetic field of the trap. With the double Penning trap method the g -factor of the antiproton can be determined with an accuracy of 1 ppb.
Nuclear charge radii and electromagnetic moments of radioactive scandium isotopes and isomers
2011
International audience; Collinear laser spectroscopy experiments with the Sc + transition 3d4s 3 D 2 → 3d4p 3 F 3 at λ = 363.1 nm were performed on the 42−46 Sc isotopic chain using an ion guide isotope separator with a cooler-buncher. Nuclear magnetic dipole and electric quadrupole moments as well as isotope shifts were determined from the hyperfine structure for five ground states and two isomers. Extensive multi-configurational Dirac-Fock calculations were performed in order to evaluate the specific mass-shift, M SMS, and field-shift, F, parameters which allowed evaluation of the charge radii trend of the Sc isotopic sequence. The charge radii obtained show systematics more like the Ti r…
Spin and magnetic moment of25Na by ?-radiation detected optical pumping
1975
25Na (T1/2 = 60 sec) has been produced in a22Ne target by the (α,p) reaction and polarized by means of spin-exchange scattering with optically pumped87Rb. The asymmetry in the β decay of polarized nuclei served to detect rf transitions between hfs Zeeman levels of the atomic ground state, yielding spinI = 5/2 and hyperfine splitting ΔW= 2648.5(3.0) MHz, from which the magnetic moment μI = 3.683(4)nm (corrected for diamagnetism) was deduced.
Role of Chiral Two-Body Currents in Li6 Magnetic Properties in Light of a New Precision Measurement with the Relative Self-Absorption Technique
2021
A direct measurement of the decay width of the excited ${0}_{1}^{+}$ state of $^{6}\mathrm{Li}$ using the relative self-absorption technique is reported. Our value of ${\mathrm{\ensuremath{\Gamma}}}_{\ensuremath{\gamma},{0}_{1}^{+}\ensuremath{\rightarrow}{1}_{1}^{+}}=8.17(14{)}_{\mathrm{stat}.}(11{)}_{\mathrm{syst}.}\text{ }\text{ }\mathrm{eV}$ provides sufficiently low experimental uncertainties to test modern theories of nuclear forces. The corresponding transition rate is compared to the results of ab initio calculations based on chiral effective field theory that take into account contributions to the magnetic dipole operator beyond leading order. This enables a precision test of the im…