Speaker
Dr
Alexander Kaloshin
(Irkutsk State University)
Description
Standard calculation of polarization of final electron for pure initial state may be reformulated as a problem of looking for the complete polarization axis of produced state. In this problem the scattering amplitude is used (instead of its square in standard approach) and it gives method for calculation of polarization applicable for both final and intermediate state fermions. For this purpose it is convenient to use fermion propagator (bare or dressed) in form of spectral representation, which is based on eigenvalue problem and gives the system of orthogonal off-shell energy projectors.
These two poins together: (i) problem of looking for the complete polarization axis and (ii) spectral representation of fermion propagator allow to give a corrrect definition for polarization of intermediate fermion.
Most interesting is the case of fermion resonance (i.e. dressed propagator) in theory with P-parity violation. Corresponding the energy projection operators differ from the standard off-shell projectors and also contain $\gamma^{5}$. Moreover, in such theory the standard spin projectors do not commute with propagator and also should be modified.
The obtained projectors are used to give the most accurate parametrization of t-quark resonance curve and simultaneously for its off-shell polarization.
Primary author
Dr
Alexander Kaloshin
(Irkutsk State University)
Co-author
Dr
Vladimir Lomov
(Institute for System Dynamics and Control Theory of SB RAS)
Peer reviewing
Paper
Paper files:
