Explanation of difference in one-neutron knockout cross sections between odd-odd and even-even projectiles with equal neutron and proton numbers

Experimental measurements of cross sections for knockout of one neutron from even-even and odd-odd projectiles with equal proton and neutron numbers at energies of about 600 MeV/nucleon on a hydrogen target show that the cross section for odd-odd projectiles is about three times smaller than for even-even projectiles and Monte Carlo calculations are used to explain this difference.