====== TTP99-03 Positronium S state spectrum: analytic results at O(m alpha^6) ======
 
 
   <hidden TTP99-03  Positronium S state spectrum: analytic results at O(m alpha^6) > We present an analytic calculation of the O(m alpha^6) recoil
 and radiative recoil corrections to energy levels of positronium 
 nS states and their hyperfine splitting. A complete analytic formula 
 valid to O(m alpha^6) is given for the spectrum of S states.
 Technical aspects of the calculation are discussed in detail. 
 Theoretical predictions are given for various energy intervals 
 and compared with experimental results. 
 </hidden>
|**Andrzej Czarnecki, Kirill Melnikov, and Alexander Yelkhovsky**  | 
|**  Phys. Rev.  A59 4316-4330 1999  **  |
| {{preprints:1999:ttp99-03.pdf|PDF}} {{preprints:1999:ttp99-03.ps|PostScript}} [[http://arxiv.org/abs/hep-ph/9901394|arXiv]]   |
| |