Relativistic effects in proton-induced deuteron break-up at intermediate energies with forward emission of a fast proton pair

Abstract.Recent data of the reaction $pd \to (pp) n$ with a fast forward pp pair with small excitation energy is analyzed within a covariant approach based on the Bethe-Salpeter formalism. Relativistic effects in cross-section are extracted and found to be large. It is demonstrated that the node of the non-relativistic amplitude is shifted and masked by relativistic effects from Lorentz boost and the negative-energy P components in the 1S0 Bethe-Salpeter amplitude of the pp pair.