Dirac Sea Effects on Superfluidity in Nuclear Matter
  We study two kinds of Dirac sea effects on the $^1S_0$ pairing gap in nuclear matter based on the relativistic Hartree approximation to quantum hadrodynamics and the Gor'kov formalism. We show that the vacuum fluctuation effect on the nucleon effective mass is more important than the direct coupling between the Fermi sea and the Dirac sea due to the pairing interaction. The effects of the high-momentum cutoff are also discussed. 
Masayuki Matsuzaki (Fukuoka Univ. of Educ.)