Positronium is the simplest bound state, built of an electron and a positron. Studies of positronium in vacuum and its decays in medium tell us about quantum electrodynamics (QED) and about the structure of matter and biological processes of living organisms at the nanoscale, respectively. Spectroscopic measurements constrain our understanding of QED bound state theory. Searches for rare decays and measurements of the effect of gravitation on positronium are used to look for new physics phenomena. In biological materials positronium decays are sensitive to the intermolecular and intramolecular structure and to the metabolism of living organisms ranging from single cells to human beings. This leads to new ideas of positronium imaging in medicine using the fact that during positron emission tomography (PET) as much as 40% of positron annihilation occurs through the production of positronium atoms inside the patient’s body. A new generation of the high sensitivity and multiphoton total-body PET systems opens perspectives for clinical applications of positronium as a biomarker of tissue pathology and the degree of tissue oxidation.

中文翻译：

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座谈会：正电子物理和生物医学应用

正电子是最简单的束缚态，由电子和正电子组成。对真空中的正电子及其在介质中的衰变的研究分别告诉我们量子电动力学（QED）以及纳米尺度的物质结构和生物体的生物过程。光谱测量限制了我们对 QED 束缚态理论的理解。寻找罕见的衰变和测量引力对正电子素的影响被用来寻找新的物理现象。在生物材料中，正电子衰变对分子间和分子内结构以及从单细胞到人类的生物体的新陈代谢敏感。这引发了医学中正电子成像的新想法，利用以下事实：在正电子发射断层扫描 (PET) 过程中，多达 40% 的正电子湮灭是通过患者体内产生正电子原子而发生的。新一代高灵敏度多光子全身 PET 系统为正电子素作为组织病理学和组织氧化程度的生物标志物的临床应用开辟了前景。