3 research outputs found
Optical activity of neutrinos and antineutrinos
Using the one-loop helicity amplitudes for low-energy
and scattering in the standard model with
massless neutrinos, we study the optical activity of a sea of neutrinos and
antineutrinos. In particular, we estimate the values of the index of refraction
and rotary power of this medium in the absence of dispersion.Comment: Additional reference
Photons, neutrinos and optical activity
We compute the one-loop helicity amplitudes for low-energy
scattering and its crossed channels in the standard
model with massless neutrinos. In the center of mass, with , the cross sections for these channels grow roughly
as . The scattered photons in the elastic channel are circularly
polarized and the net value of the polarization is non-zero. We also present a
discussion of the optical activity of a sea of neutrinos and estimate the
values of its index of refraction and rotary power.Comment: 9 pages, ReVTeX4, 6 figures include
A geometric approach to time evolution operators of Lie quantum systems
Lie systems in Quantum Mechanics are studied from a geometric point of view.
In particular, we develop methods to obtain time evolution operators of
time-dependent Schrodinger equations of Lie type and we show how these methods
explain certain ad hoc methods used in previous papers in order to obtain exact
solutions. Finally, several instances of time-dependent quadratic Hamiltonian
are solved.Comment: Accepted for publication in the International Journal of Theoretical
Physic