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Gamow-Jordan Vectors and Non-Reducible Density Operators from Higher Order S-Matrix Poles

A. Bohm·M. Loewe·S. Maxson·P. Patuleanu·C. Puntmann·M. Gadella
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Abstract

In analogy to Gamow vectors that are obtained from first order resonance poles of the S-matrix, one can also define higher order Gamow vectors which are derived from higher order poles of the S-matrix. An S-matrix pole of r-th order at z_R=E_R-iΓ/2 leads to r generalized eigenvectors of order k= 0, 1, ... , r-1, which are also Jordan vectors of degree (k+1) with generalized eigenvalue (E_R-iΓ/2). The Gamow-Jordan vectors are elements of a generalized complex eigenvector expansion, whose form suggests the definition of a state operator (density matrix) for the microphysical decaying state of this higher order pole. This microphysical state is a mixture of non-reducible components. In spite of the fact that the k-th order Gamow-Jordan vectors has the polynomial time-dependence which one always associates with higher order poles, the microphysical state obeys a purely exponential decay law.

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A. Bohm, M. Loewe, S. Maxson, P. Patuleanu, C. Puntmann, M. Gadella. 1997-05-07. Gamow-Jordan Vectors and Non-Reducible Density Operators from Higher Order S-Matrix Poles. https://doi.org/10.1063/1.532203

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