Unstable Systems in Relativistic Quantum Field Theory

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.

Unstable Systems and Quantum Zeno Phenomena in Quantum Field Theory

We analyze the Zeno phenomenon in quantum field theory. The decay of an unstable system can be modified by changing the time interval between successive measurements (or by varying the coupling to an external system that plays the role of measuring apparatus). We speak of quantum Zeno effect if the decay is slowed and of inverse quantum Zeno (or Heraclitus) effect if it is accelerated. The anal...

Relativistic Quantum Field Theory

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...

Unstable Bundles in Quantum Field Theory

The relation between connections on 2-dimensional manifolds and holomorphic bundles provides a new perspective on the role of classical gauge fields in quantum field theory in two, three and four dimensions. In particular we show that there is a close relation between unstable bundles and monopoles, sphalerons and instantons. Some of these classical configurations emerge as nodes of quantum vac...