A novel method to measure the isotope shifts and hyperfine splittings of all ytterbium isotopes for a 399-nm transition

We report the experimental results on measuring the isotope shifts and hyperfine splittings of all ytterbium isotopes for a 399-nm transition by using a quite simple and novel method. It benefits from the advantages of the modulation transfer spectroscopy in an ytterbium hollow cathode lamp and the Doppler-free spectroscopy in a collimated ytterbium atomic beam. The key technique in this experiment is simultaneously measuring the frequency separations of the two spectra twice, and the separation difference between two measurements is solely determined by the well-defined frequency of an acousto-optics modulator. Compared with the most of previously reported experimental results, ours are more accurate and completed, which will provide the useful information for developing a more accurate theoretical model to describe the interaction inside an ytterbium atom.

Saturated absorption spectrum of cesium micrometric-thin cell with suppressed crossover spectral lines

Micrometric-thin cells(MCs)with alkali vapor atoms have been valuable for research and applications of hyperfine Zeeman splitting and atomic magnetometers under strong magnetic fields.We theoretically and experimentally study the saturated absorption spectra using a 100-μm cesium MC,where the pump and probe beams are linearly polarized with mutually perpendicular polarizations,and the magnetic field is along the pump beam.Because of the distinctive thin chamber of the MC,crossover spectral lines in saturated absorption spectra are largely suppressed leading to clear splittings of hyperfine Zeeman transitions in experiments,and the effect of spatial magnetic field gradient is expected to be reduced.A calculation method is proposed to achieve good agreements between theoretical calculations and experimental results.This method successfully explains the suppression of crossover lines in MCs,as well as the effects of magnetic field direction,propagation and polarization directions of the pump/probe beam on saturated absorption spectrum.The saturated absorption spectrum with suppressed crossover lines is used for laser frequency stabilization,which may provide the potential value of MCs for high spatial resolution strong-field magnetometry with high sensitivity.

Annihilation diagram contribution to charmonium masses

In this work,we generate gauge configurations with N_(f)=2 dynamical charm quarks on anisotropic lattices.The mass shift of 1S and 1P charmonia due to the charm quark annihilation effect can be investigated directly in a manner of unitary theory.The distillation method is adopted to treat the charm quark annihilation diagrams at a very precise level.For 1S charmonia,the charm quark annihilation effect barely changes the J/ψmass,but lifts theη_(c) mass by approximately 3-4 MeV.For 1P charmonia,this effect results in positive mass shifts of approximately 1 MeV for χ_(c)1 and h_(c),but decreases the χ_(c)2 mass by approximately 3 MeV.We did not obtain a reliable result for the mass shift of χ_(c)0.In addition,we observed that the spin averaged mass of the spin-triplet 1P charmonia is in good agreement with h_(c),as expected by the non-relativistic quark model and measured by experiments.