The twonucleon system at nexttonexttonexttoleading order
Abstract
We consider the twonucleon system at nexttonexttonexttoleading order (N ^{3}LO) in chiral effective field theory. The twonucleon potential at N ^{3}LO consists of one, two and threepion exchanges and a set of contact interactions with zero, two and four derivatives. In addition, one has to take into account various isospinbreaking and relativistic corrections. We employ spectral function regularization for the multipion exchanges. Within this framework, it is shown that the threepion exchange contribution is negligibly small. The lowenergy constants (LECs) related to pionnucleon vertices are taken consistently from studies of pionnucleon scattering in chiral perturbation theory. The total of 26 fournucleon LECs has been determined by a combined fit to some np and pp phase shifts from the Nijmegen analysis together with the nn scattering length. The description of nucleonnucleon scattering and the deuteron observables at N ^{3}LO is improved compared to the one at NLO and NNLO. The theoretical uncertainties in observables are estimated based on the variation of the cutoffs in the spectral function representation of the potential and in the regulator utilized in the LippmannSchwinger equation.
 Publication:

Nuclear Physics A
 Pub Date:
 January 2005
 DOI:
 10.1016/j.nuclphysa.2004.09.107
 arXiv:
 arXiv:nuclth/0405048
 Bibcode:
 2005NuPhA.747..362E
 Keywords:

 Nuclear Theory;
 High Energy Physics  Phenomenology;
 Nuclear Experiment
 EPrint:
 62 pp, 13 figs