Toward a QFT treatment of nonexponential decay

  • We study the properties of the survival probability of an unstable quantum state described by a Lee Hamiltonian. This theoretical approach resembles closely Quantum Field Theory (QFT): one can introduce in a rather simple framework the concept of propagator and Feynman rules, Within this context, we re-derive (in a detailed and didactical way) the well-known result according to which the amplitude of the survival probability is the Fourier transform of the energy distribution (or spectral function) of the unstable state (in turn, the energy distribution is proportional to the imaginary part of the propagator of the unstable state). Typically, the survival probability amplitude is the starting point of many studies of non-exponential decays. This work represents a further step toward the evaluation of the survival probability amplitude in genuine relativistic QFT. However, although many similarities exist, QFT presents some differences w.r.t. the Lee Hamiltonian which should be studied in the future.

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Author:Francesco GiacosaORCiDGND
Parent Title (English):EPJ Web of Conferences
Publisher:EDP Sciences
Place of publication:Les Ulis
Document Type:Conference Proceeding
Year of Completion:2018
Date of first Publication:2018/08/03
Publishing Institution:Universit├Ątsbibliothek Johann Christian Senckenberg
Contributing Corporation:6th International Conference on New Frontiers in Physics (ICNFP 2017)
Release Date:2019/04/10
Issue:Article Number 02045
Page Number:10
Institutes:Physik / Physik
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
Licence (German):License LogoCreative Commons - Namensnennung 4.0