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Positronium in physics, biology and medicine Paweł Moskal (Jagiellonian Univeristy in Kraków)

The first PET tomograph based on plastic scintillators was designed and built at the Institute of Physics of the Jagiellonian University.

Jagiellonian PET (J-PET) is a unique research device on a global scale that allows not only to visualize the metabolism of selected substances in living organisms, but also for imaging tissue pathology in-vivo by measuring the properties of positronium (an atom made of electron and positron).

Tissue pathology imaging is a unique feature of the J-PET tomograph based on the fact that during PET diagnosis positronium atoms are formed in human tissues in intramolecular spaces (atoms composed of an electron from tissue and a positron emitted by a radioisotope).

This phenomenon, not used so far in medicine, may create new possibilities for medical diagnostics.

For example, the average lifetime of positronium within tissues depends on the size of free space between atoms and on the concentration of free radicals in cells and can serve as a new indicator (bio-marker) for determining the degree of malignancy in tumors in vivo.

A positronium atom, being a system built of electron and positron bound by electromagnetic interaction, is both an atom and an anti-atom. As an atom made of electron and anti-electron, unlike ordinary atoms, is symmetrical when exchanging particles for antiparticles.

That is why positronium is an ideal system for studying symmetry between matter and antimatter in nature.

In particular, it enables tests of invariance of physical phenomena due to discrete transformations (symmetries) such as: conversion of particles into antiparticles (C), reversal of time (T), spatial reflection (P) and combinations of these symmetries, such as CP or CPT. Discrete symmetry tests touch upon fundamental questions such as:

Why stars exist? Why do we exist? Why does the universe exist? Are there other particles and forces unknown to us that are responsible for the survival of matter to our times?

The survival of matter in the universe remains an unexplained mystery, given the far too small measured asymmetry between matter and antimatter, so far observed only in processes of weak interaction. To date, no signs of similar asymmetries have been observed in gravitational, electromagnetic and strong interactions.

The lecture will discuss the principle of the J-PET tomograph and its possible applications for studying metabolism throughout the whole human body simultaneously. Also discussed will be the principle of positronium imaging, the principle of testing discrete symmetry with a J-PET tomograph, as well as the principle of measuring the polarization and quantum entanglement of photons formed as a result of positronium annihilation.

J-PET as a tomograph made of plastic detectors is currently a unique device that allows the study of quantum entanglement of photons arising from positronium annihilation. The first positronium images and the results of discrete symmetry tests in positronium atom decays obtained with J-PET tomograph will also be presented.

They are so far the most precise tests in the world in electrically charged leptons

J-PET technology makes it possible to build a PET tomograph for the entire human body – the total-body PET. Access to such a device would open up new research opportunities in medicine, including, for example:

  • pharmacokinetic studies of new compounds or drug binding at the tissue level in vivo,
  • in-vivo detection of malignancy,
  • research on metabolic and chronic diseases at the cellular and tissue level.

The lecture will also discuss the prospects of building such a total-body PET in Poland.

The subject of scientific interest and research work of prof. Paweł Moskal is nuclear physics, particle physics and the application of physics in medicine and public security.

He leads an interdiciplinary team of over fourty researchers studying phenomena in which the energy turns into matter and the phenomenon of the annihilations of particles into photons. He is searching for new types of matter as well as natural phenomena that may break fundamental symmetries, such as the reflection in space or the reversal in time. He developed a new method of non-invasive imaging of the human interior based on plastic detectors and in-vivo imaging of the positronium properties in the living organisms, opening new possibilities for cancer diagnosis.

Pawel Moskal, Ph.D. is an inventor of positron emission tomography based on plastic scintillators and method of in-vivo pathology based on positronium imaging.

He is Professor of physics and the head of the Cluster of Nuclear Physics Departments and the Department of Particle Physics and Applications at the Jagiellonian University in Cracow, Poland. He won the Prime Minister’s award for his doctoral dissertation in 1999 and a Gold Medal for the invention of the matrix device for Positron Emission Tomography at The World Exhibition on Innovation, Research and New Technologies at Brussels Innova 2009.

Prof. Moskal has co-authored 18 patent in Europe, USA and Japan, and more than 300 scientific articles in the field of nuclear and particle physics and positron emission tomography. In the years 2015-2017 he was a member of the SPSC Scientific Committee at CERN. At present he is leading the J-PET collaboration: an international and interdisciplinary research team at the Jagiellonian University conducting research and development of a new imaging device based on plastic scintillators. This research aims at the construction of a cost effective portable and modular total-body PET for experiments with positronium in basic physics, biophysics and medical diagnostics, e.g. for studies of discrete symmetries in the decays of positronium, the development and tests of multi-photon imaging, and the study of properties of positronium atoms in living organisms, opening new perspectives to study the dynamics of metabolism and tissue pathology in-vivo in the whole human body simultaneously.

Prof. Moskal was coordinator of the COSY-11 international collaboration conducting experiments on meson production at the Cooler Synchrotron COSY at FZ-Jülich in Germany and deputy-coordinator of the WASA-at-COSY experiment, which comprises about 150 physicists testing fundamental symmetries in nature by means of the decays of mesons. He is also a member of the KLOE-2 collaboration conducting experiments at the electron-positron collider DAFNE in Italy. The KLOE-2 experiments include tests of quantum mechanics and searching for phenomena beyond the standard model of particle physics. Prof. Moskal chaired the scientific and organizing committees of fifteen international symposia and workshops devoted to fundamental and applied physics and served as the (co-)editor of the proceedings books.

The most important papers:

  1. P. Moskal, B. Jasińska, E. Stępień, S. Bass, Nature Reviews Physics 1 (2019) 527
  2. P. Moskal et al., Physics in Medicine and Biology 64 (2019) 055017
  3. B. Hiesmayr, P. Moskal, Scientific Reports 9 (2019) 8166

October 17, 2020 at 5:00pm

Auditorium of the Faculty of Physics, Univeristy of Warsaw

Credits:

Photos by Paweł Moskal.