0000000000672617
AUTHOR
Torleif Erik Oskar Ericson
Effects of the axial isoscalar neutral current for solar neutrino detection
Abstract An essential assumption in the analysis of all the large solar neutrino experiments sensitive to neutral currents has been that the axial transitions are purely isovector. The recent results on the spin structure of the proton suggest the presence of an axial isoscalar neutral-current interaction. This would modify the assumed transition strengths for the neutral-current detection of solar neutrinos. We demonstrate that in the long wavelength limit a deuterium target is insensitive to such a mechanism. Our results for the situation of the planned BOREX experiment show that the suggested isoscalar strength would increase the observed rate by 30–40%, depending on the transition.
Polarizability effects in electronic and muonic atoms
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.
Neutron polarizability and the n-e scattering length
Abstract It is shown that the neutron polarizability contribution to the n-e scattering length is within the present level of precision. The experimental result on this interaction is consistent with a value of the neutron polarizability similar to the proton one.