Quartet S wave neutron deuteron scattering in effective field theory

The real and imaginary part of the quartet S wave phase shift in nd scatter ing (S-4(3/2)) for centre-of-mass momenta of up to 300 MeV (E-cm approximat e to 70 MeV) is presented in effective field theory, using both perturbativ e pions and a theory in which pions are integrated out. As available, the c alculation agrees with both experimental data and potential model calculati ons, but extends to a higher, so far untested momentum regime above the deu teron breakup point. A Lagrangean more feasible for numerical computations is derived. (C) 2000 Elsevier Science B.V. All rights reserved.