The lifetimes for each state of l=0 levels of the para-positronium

Güvendi A. , Sucu Y.

European Physical Journal Plus, sa.5, ss.1-7, 2021 (SCI İndekslerine Giren Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1140/epjp/s13360-021-01425-9
  • Dergi Adı: European Physical Journal Plus
  • Sayfa Sayıları: ss.1-7


We developed a model for a para-Positronium system by taking into account the annihilation

condition which requires l = 0. A para-Positronium system composed by an electron-antielectron pair is an

unstable system that decays predominantly into two gamma photons via self annihilation process. This is

because of the conservation of (overall) charge conjugation parity. Our 2+1 dimensional model was based

on an exact solution of a two-body Dirac-Coulomb type equation (one-time). The result non-perturbative

spectra was found to have a form of quasi normal modes that naturally give proper and damping oscillations

of the system. As a result, with a single equation, not only the binding energies and total annihilation

energy transmitted by the annihilation photons but also the life times, .., for each state

of l = 0 levels of the para-Positronium was obtained. With this unique presentation of above mentioned

characteristic of the system, we also calculated transition frequencies and transition times between differing

n level of l = 0. This also gave us an opportunity to discuss the screening effect from electronic environment

of the system. For this, the effective dielectric constant of the medium that surrounds the annihilation

point was adapted into the calculated non-perturbative spectra. This may provide an important tool for

the positron annihilation lifetime spectroscopy studies and for development of related techniques.