Quantum jumps and electrodynamical description

Leonardo Chiatti (ASL VT Medical Physics Laboratory)
The customary description of radiation processes provided by Quantum Electrodynamics (QED) allows the quantitative derivation of many physical observables, in line with experiments. This extraordinary empirical success, however, leaves open the problem of the ontology of these processes. We identify these with the discontinuities of the evolution of the quantum state of the source, the so-called quantum jumps (QJ). Adopting a time-symmetrical view of the QJ borrowed from the transactional approach, the phenomena of radiation emission and absorption by an electron acquire an adynamic aspect, associated with their emergence from an atemporal background. The QJ activates the progressive generation of the electron timeline, along which its asymptotic state evolves. This causation process is of the formal type, and its dynamic “shadow” on the time domain is constituted by an interval during which the electron is self-interacting. Instead, in the absence of further interaction with external fields the asymptotic state is “on shell” i.e. not self-interacting. These ideas are used to constraint the value of the fine structure constant and of the cosmological constant, and to illustrate some less-known properties of electroweak decays. Full text


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