2008/05/05 by N. G. Kelkar, M. Nowakowski · 21 citations
Mathematics · Physics and Astronomy · #Channel (broadcasting) #Computer science #Hermitian matrix #Laser-Matter Interactions and Applications #Mathematical analysis #Mathematics #Matrix (chemical analysis) #Physics #Quantum chaos and dynamical systems #Quantum mechanics #Quantum optics and atomic interactions #Telecommunications #hep-ph #nucl-th #quant-ph
paper · pdf · doi:10.1103/physreva.78.012709
published in Physical Review A 78(1) (American Physical Society) · 15 pages, LaTex
arxiv created 2008/05/05 · openalex publication_date 2008/07/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The physical significances and the pros and cons involved in the usage of different time-delay formalisms are discussed. The delay-time matrix introduced by Eisenbud, where only s waves participate in a reaction, is in general related to the definition of an angular time delay which is shown not to be equivalent to the so-called phase time delay of Eisenbud and Wigner even for single channel scattering. Whereas the expression due to Smith which is derived from a time-delayed radial wave packet is consistent with a lifetime matrix which is Hermitian, this is not true for any Eisenbud-type lifetime matrix which violates time-reversal invariance. Extending the angular time delay of Nussenzveig to multiple channels, we show that if one performs an average over the directions and subtracts the forward angle contribution containing an interference of the incident and scattered waves, the multichannel angle-dependent average time delay reduces to the one given by Smith. The present work also rectifies a recently misinterpreted misnomer of the relation due to Smith.