Which is the quantum decay law of relativistic particles?

Alavi, S. A.; Giunti, C.

doi:10.1209/0295-5075/109/60001

Cited by 15 publications

(25 citation statements)

References 15 publications

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“…These important aspects of the early and late time evolution of unstable states in quantum field theory continue to be studied at a deeper level [13,[16][17][18][19][20][21][22][23][24].…”

mentioning

confidence: 99%

Quantum decay in renormalizable field theories: Quasiparticle formation, Zeno and anti-Zeno effects

Boyanovsky

2019

Annals of Physics

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In a renormalizable theory the survival probability of an unstable quantum state features divergences as a consequence of the rapid growth of the density of states with energy. Introducing a high energy cutoff Λ, the transient dynamics during a time scale ≃ 1/Λ describes the renormalization of the bare into a "quasiparticle" state which decays on longer time scales. During this early transient the decay law features Zeno behavior e −(t/tZ ) 2 with the Zeno time-scale t Z ∝ 1/Λ 3/2 . We introduce a dynamical renormalization framework that allows to separate consistently the dynamics of formation of the quasiparticle state and its decay on longer time scales by introducing a renormalization time scale along with alternative "schemes". The survival probability obeys a renormalization group equation with respect to this scale. We find a transient suppression of the decay law for large Lorentz factor as a consequence of the narrowing of the phase space for decay different from the usual time dilation. In presence of higher mass thresholds, the energy uncertainty associated with transient dynamics leads to an anti Zeno enhancement with a transient acceleration of the decay into heavier particles. There remains memory of the transient effects in the survival probability even at long time. We discuss possible consequences of these effects in cosmology.

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“…These important aspects of the early and late time evolution of unstable states in quantum field theory continue to be studied at a deeper level [13,[16][17][18][19][20][21][22][23][24].…”

mentioning

confidence: 99%

Quantum decay in renormalizable field theories: Quasiparticle formation, Zeno and anti-Zeno effects

Boyanovsky

2019

Annals of Physics

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“…A further interesting topic for the future is the study of the decay of a particle with a nonzero momentum [29][30][31][32][33][34]. Contrary to naive expectations, the usual relativistic time dilatation formula does not hold (even in the exponential limit, a different analytical result is obtained, see details in Ref.…”

Section: Discussionmentioning

confidence: 99%

Toward a QFT treatment of nonexponential decay

Giacosa

2018

EPJ Web Conf.

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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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“…They use the definition (2) of the survival probability mentioned earlier: P 0 (t) = |a 0 (t)| 2 of the unstable system in rest. The final result is obtained in [12] for states connected with the "reference frame in which the system is in motion with velocity v". In this new reference frame the momentum of the particle equals k m and k m = p, where p is the momentum of the same particle but in the rest frame of the observer.…”

Section: Moving Unstable Systemsmentioning

confidence: 99%

“…φ( p) is the momentum distribution such that d 3 p |φ( p)| 2 = 1. The energy E m ( k m ) and momentum k m in the new reference frame mentioned are connected with E m ( p) and p in the rest frame by Lorentz transformations (see (33) -(35) in [12]),…”

Section: Moving Unstable Systemsmentioning

confidence: 99%