Relativistic effects in proton-induced deuteron break-up at intermediate   energies with forward emission of a fast proton pair
  Recent data on the reaction pD -> (pp) n with a fast forward pp pair with very small excitation energy is analyzed within a covariant approach based on the Bethe-Salpeter formalism. It is demonstrated that the minimum non-relativistic amplitude is completely masked by relativistic effects, such as Lorentz boost and the negative-energy P components in the 1S_0 Bethe-Salpeter amplitude of the pp pair. 
L.P. Kaptari, B. Kampfer, S.S. Semikh, S.M. Dorkin