Spectra of unbound electron–positron pairs (dielectrons, in brief) and photons from decays of parapositronia produced in ultraperipheral collisions of electrically charged objects are calculated. Their shapes at energies of the NICA collider are demonstrated. Soft dielectrons and photons are abundantly produced. The relevance of these processes to the astrophysical problem of cooling electron–positron pairs and the intense emission of 511 keV photons from the Galactic center is discussed.

中文翻译：

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软双电子和光子的过量

计算了带电物体的超周边碰撞中产生的未结合的电子-正电子对（简而言之为双电子）和来自正负电子的衰变的光子的光谱。展示了它们在NICA对撞机能量下的形状。大量产生软的双电子和光子。讨论了这些过程与冷却电子-正电子对的天体物理学问题以及来自银河系中心的511 keV光子的强发射的相关性。