Orthopositronium: "On the possible relation of gravity to electricity"
  The resolve of the 'orthopositronium-lifetime puzzle' needs study of the "isotope anomaly" in gaseous neon and also of the contribution ~ 0.002 of nonperturbative mode into orthopositronium annihilation. The Michigan results (2003) are considered as the first supervision of relation between gravitation and electricity. For the decision of alternative in interpretation of new and former results it is necessary to execute the program of additional measurements. 
B.A. Kotov, B.M. Levin, and V.I. Sokolov