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SUMMARY:Open quantum systems approach in quantum field theory
DTSTART;VALUE=DATE-TIME:20261030T074500Z
DTEND;VALUE=DATE-TIME:20261030T080000Z
DTSTAMP;VALUE=DATE-TIME:20261102T005407Z
UID:indico-contribution-6160@cern.ch
DESCRIPTION:Speakers: Vladislav Motovilov (Lomonosov Moscow State Universi
 ty\, Faculty of Physics)\nThe standard paradigm of neutrino oscillations a
 ssumes that neutrinos propagate as a coherent superposition of mass eigens
 tates. However\, in a number\nof physical scenarios — including wave pac
 ket spreading\, quantum gravity effects\, spacetime fluctuations\, or inte
 ractions with a hot or dense medium —\nthis coherence can be violated\, 
 leading to the phenomenon of neutrino decoherence. Decoherence manifests i
 tself as an exponential damping of the interference\nterms in the oscillat
 ion probability and\, consequently\, can modify predictions\nfor oscillati
 on experiments. Searches for such effects are actively pursued using\ndata
  from reactor experiments (KamLAND\, Daya Bay\, RENO) and accelerator expe
 riments (MINOS/MINOS+\, T2K\, NOvA)\, and are also part of the\nphysics pr
 ogramme of future facilities such as JUNO and DUNE. The theoretical descri
 ption of decoherence naturally fits within the open quantum systems\nframe
 work\, where neutrinos are treated as a subsystem interacting with a quant
 um environment.\n\nIn this work\, the open quantum systems formalism is ap
 plied to the dynamics\nof neutrinos in a thermal bath of bosons at finite 
 temperature. Within the\nMarkov and secular approximations\, a reduced kin
 etic equation for the neutrino\ndensity matrix is derived from the von Neu
 mann equation for the total ”neutrino\n+ environment” system\, yieldin
 g a Lindblad-type master equation. It is shown\nthat the resulting equatio
 n naturally unifies coherent and dissipative processes:\nthe commutator te
 rm governs the unitary evolution\, including corrections to the\nHamiltoni
 an\, while the dissipative part describes incoherent processes associated\
 nwith neutrino decay and its inverse process in the medium.\n\nhttps://ind
 ico.particle.mephi.ru/event/626/contributions/6160/
LOCATION: Conference Hall 3
URL:https://indico.particle.mephi.ru/event/626/contributions/6160/
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