Paschen-Back Effect of Hyperfine Structure and Polarization of Resonance Radiation: Sodium

Preliminary measurements on the polarization of resonance radiation of the second doublet of sodium when a magnetic field is applied with its direction parallel to the incident light beam shows that the polarization changes from a value of about 10 per cent in zero magnetic field to a value of 34 per cent in fields less than 100 gausses. In order that a Paschen-Back effect of the hyperfine structure of the 52P 1/2 , 3/2 levels should occur in field strengths of this order of magnitude the hyperfine separation constant for these levels must be of the order.0005 x 10-3 cm-1

Paschen-Back Effect of Hyperfine Structure and Polarization of Resonance Radiation: Cadmium (61P1-51S1)

Because of the Paschen-Back effect of the hyperfine structure of the odd isotopes, the polarization of cadmium λ2288A resonance radiation excited by plane polarized incident light changes from 76.7 per cent in zero field to 100 per cent in a strong field parallel to the electric vector of the exciting light

Ab initio alpha-alpha scattering

Processes involving alpha particles and alpha-like nuclei comprise a major part of stellar nucleosynthesis and hypothesized mechanisms for thermonuclear supernovae. In an effort towards understanding alpha processes from first principles, we describe in this letter the first ab initio calculation of alpha-alpha scattering. We use lattice effective field theory to describe the low-energy interactions of nucleons and apply a technique called the adiabatic projection method to reduce the eight-body system to an effective two-cluster system. We find good agreement between lattice results and experimental phase shifts for S-wave and D-wave scattering. The computational scaling with particle number suggests that alpha processes involving heavier nuclei are also within reach in the near future.Comment: 6 pages, 6 figure