Foundations of Physics

, Volume 10, Issue 9–10, pp 723–730 | Cite as

On the actual measurability of the density matrix of a decaying system by means of measurements on the decay products

  • S. Bergia
  • F. Cannata
  • A. Cornia
  • R. Livi


The density matrix ρ describing a decaying system can be expressed in terms of correlations among observables belonging to the subsystems. Due to this structure and to the difficulties in measuring higher rank tensors of decay products for a single decay event, it is found that the mean value of ρ cannot be determined, in general, from measurements on the decay products. We also discuss the consequences of this conclusion as far as tests of quantum mechanics are concerned.


Quantum Mechanic Density Matrix Actual Measurability High Rank Decay Product 
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Copyright information

© Plenum Publishing Corporation 1980

Authors and Affiliations

  • S. Bergia
    • 1
  • F. Cannata
    • 1
  • A. Cornia
    • 2
  • R. Livi
    • 3
  1. 1.Bologna, Italy and Istituto Nazionale di Fisica Nucleare Sezione di BolognaIstituto di Fisica dell'UniversitàItaly
  2. 2.Istituto Nazionale di Fisica Nucleare, Sezione di Bologna, Italy and Scuola di Perfezionamento in FisciaUniversità di BolognaItaly
  3. 3.Istituto Nazionale di Fisica Nucleare, Sezione di TriesteItaly

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