Relativistic corrections in the ground and excited states of positronic beryllium
Tumakov D. Rzhevskii P. Shomenov T. Bubin S.
April 2024American Physical Society
Physical Review A
2024#109Issue 4
Positron binding to neutral atoms, which to this day have not been detected experimentally, is thought to be rather weak. According to a few reliable nonrelativistic calculations reported previously, the positron affinity for small atoms, even if it happens to be positive, is predicted to be very small in magnitude, of the order of just few millihartrees (<0.1eV). In this work, we used a highly accurate variational expansion in terms of explicitly correlated Gaussians to investigate how relativistic effects may affect the stability of bound states of positrons with atoms. We performed calculations of positronic beryllium, e+[Be], in its ground singlet S and excited triplet S and P states, all of which are bound. According to our findings, neither the inclusion of scalar relativistic nor spin-dependent corrections alters the predictions regarding the existence of the bound states. When leading-order relativistic effects are taken into account, positron affinities change only by 2.2% or less. Notably, this is so even for the triplet P state of positronic beryllium, where the spin-orbit correction is not at all canceled out when the energy difference with the parent system is computed.
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Department of Physics, Nazarbayev University, Astana, 010000, Kazakhstan
I. Institute for Theoretical Physics, Universität Hamburg, Hamburg, 22607, Germany
Department of Physics
I. Institute for Theoretical Physics
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026