{ "id": "2002.05499", "version": "v1", "published": "2020-02-13T14:04:04.000Z", "updated": "2020-02-13T14:04:04.000Z", "title": "Transition Probabilities for Flavor Eigenstates of Non-Hermitian Hamiltonians in the PT-Broken Phase", "authors": [ "Tommy Ohlsson", "Shun Zhou" ], "comment": "20 pages, 1 figure", "categories": [ "quant-ph", "hep-ph", "hep-th", "math-ph", "math.MP" ], "abstract": "We investigate the transition probabilities for the \"flavor\" eigenstates in the two-level quantum system, which is described by a non-Hermitian Hamiltonian with the parity and time-reversal (PT) symmetry. Particularly, we concentrate on the so-called PT-broken phase, where two eigenvalues of the non-Hermitian Hamiltonian turn out to be a complex conjugate pair. In this case, we find that the transition probabilities will be unbounded in the limit of infinite time $t \\to +\\infty$. After making a connection between the PT-broken phase and the neutral-meson system in particle physics, we observe that the infinite-time behavior of the transition probabilities can be attributed to the negative decay width of one eigenstate of the non-Hermitian Hamiltonian. We also present some brief remarks on the situation at the so-called exceptional point, where both the eigenvalues and eigenvectors of the Hamiltonian coalesce.", "revisions": [ { "version": "v1", "updated": "2020-02-13T14:04:04.000Z" } ], "analyses": { "keywords": [ "transition probabilities", "pt-broken phase", "flavor eigenstates", "two-level quantum system", "non-hermitian hamiltonian turn" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }