Closing the door on the “puzzle of decoherence” of annihilation quanta

Scientific paper - Letter

• Author: Siddharth Parashari
• Author: Damir Bosnar
• Author: Ivica Friščić
• Author: Ana Marija Kožuljević
• Author: Zdenka Kuncic
• Author: Petar Žugec
• Author: Mihael Makek
• Author's institution: University of Zagreb; Faculty of Science; (Department of Physics)
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract (english)

In positron annihilation, exploration of the polarization correlations of the emerging gamma quanta has gained interest, since they offer a possibility to improve signal-to-background in medical imaging using positron emission tomography. The annihilation quanta, which are predicted to be in an entangled state, have orthogonal polarizations and this property may be exploited to discriminate them from two uncorrelated gamma photons contributing to the background. Recent experimental studies of polarization correlations of the annihilation quanta after a prior Compton scattering of one of them, had rather different conclusions regarding the strength of the correlation after the scattering, showing its puzzling nature. The scattering was described as a decoherence process. In the present work, we perform for the first time, a study of the polarization correlations of annihilation quanta after decoherence via Compton scattering in the angular range 0° − 50° using single-layer gamma ray polarimeters. In addition, we compare the measured polarization correlations after Compton scattering at 30° with an active and a passive scatterer element. The measured azimuthal correlation of back-to-back annihilation quanta is consistent with the Pryce-Ward formulation, as confirmed by Monte Carlo simulations. Further, the results indicate that the correlation, expressed in terms of the polarimetric modulation factor, shows no significant difference at small scattering angles (0° − 30°) compared to the correlation measured for direct photons, while a moderate indication of a lower modulation is observed for 50° scattering angle. The measured modulation is larger at all scattering angles than the one expected from the simulation of orthogonally polarized, independent annihilation quanta.

• Keywords (english): Positron annihilation; Quantum entanglement; Decoherence; Gamma polarization; Positron emission tomography; Monte-Carlo simulations
• Language: english
• Publication type: Scientific paper - Letter
• Publication status: Published
• Peer review: Peer review - international
• Publication version: Published version
• Journal title: Physics Letters B
• Numbering: vol. 852, 138628
• p-ISSN: 0370-2693
• DOI: https://doi.org/10.1016/j.physletb.2024.138628
• URN:NBN: urn:nbn:hr:217:945506
• Publication: 2024-05
• Project: Number: PZS-2019-02-5829; Title (croatian): Jednoslojni polarimetar gama zračenja za primjene u medicinskom oslikavanju i za temeljna istraživanja u fizici; Title (english): Single Layer Gamma-Ray Polarimeter for Medical Imaging Applications and Fundamental Physics Research; Acronym: SiLGaP; Leader: Mihael Makek; Jurisdiction: Croatia; Funding stream: Programme Research Cooperability
• Project: Number: KK.01.1.1.01.0004; Title (croatian): Provedba vrhunskih istraživanja u sklopu Znanstvenog centra izvrsnosti za kvantne i kompleksne sustave te reprezentacije Liejevih algebri; Title (english): Implementation of top research within the Scientific Center of Excellence for Quantum and Complex Systems, and Representations of Lie Algebras; Acronym: QuantiXLie; Leader: Hrvoje Buljan; Jurisdiction: eu; Funding stream: European Regional Development Fund
• Project: Number: 101038099; Title (croatian): Raspad orto-pozitronija i potraga za slamanjem CP i CPT simetrije u leptonskom sektoru; Title (english): Ortho-positronium decay and the search for CP and CPT violation in leptonic sector; Acronym: OPSVIO; Leader: Ivica Friščić; Jurisdiction: eu; Funding stream: Horizon 2020
• Project: Number: IP-2022-10-3878; Title (croatian): Precizna digitalizirana spektroskopija u fundamentalnim istraživanjima u subatomskoj fizici i primjenama; Title (english): High-precision digitized spectroscopy in fundamental research in subatomic physics and applications; Acronym: PREDISPECT; Leader: Damir Bosnar; Jurisdiction: Croatia; Funding stream: Research Projects
• Document URL: https://linkinghub.elsevier.com/retrieve/pii/S0370269324001862
• Type of resource: Text
• Access conditions: Open access
• Public note: © 2024 The Author(s). Published by Elsevier B.V. Funded by SCOAP³. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Received 9 May 2023; Received in revised form 29 March 2024; Accepted 1 April 2024. Available online 5 April 2024. Published May 2024.
• Created on: 2024-07-31 11:41:30