Polarizabilities of microparticles in relativistic field theory

Relativistic Quantum Field Theory

Quasiparticle excitations in relativistic quantum field theory

We analyze the particle-like excitations arising in relativistic field theories in states different than the vacuum. The basic properties characterizing the quasiparticle propagation are studied using two different complementary methods. First we introduce a frequency-based approach, wherein the quasiparticle properties are deduced from the spectral analysis of the twopoint propagators. Second,...

Unstable Systems in Relativistic Quantum Field Theory

We show how the state of an unstable particle can be defined in terms of stable asymptotic states. This general definition is used to discuss and to solve some old problems connected with the short-time and large-time behaviour of the non-decay amplitude. CERN-TH/97-246 September 1997 ⋆ Address from Sept 1st, 1997 to August 31st, 1998.

Relativistic Field Theory of Unstable Particles

I feel quite ashamed no t to be speaking a b o u t any indefinite metric. I a m going to confine my r emarks to the old familiar relativistic local field theory and discuss the p rob lem of creat ing a f ramework for the descript ion of uns table e lementary particles. I need n o t apologize for this. Of the sixteen k n o w n e lementary particles, only four — the p ro ton , the electron, the n...

BRST Field Theory of Relativistic Particles

A generalization of BRST field theory is presented, based on wave operators for the fields constructed out of, but different from the BRST operator. We discuss their quantization, gauge fixing and the derivation of propagators. We show, that the generalized theories are relevant to relativistic particle theories in the Brink-Di Vecchia-Howe-Polyakov (BDHP) formulation, and argue that the same p...