Sigma-terms in heavy baryon chiral perturbation theory revisited

B. Borasoy
1999 European Physical Journal C: Particles and Fields  
The σ-terms are calculated at next-to-leading order in heavy baryon chiral perturbation theory by employing a cutoff regularization. The results do not depend on the cutoff value to the order we are working . The baryon masses and σ πN (0) are used to perform a least-squares fit to the three appearing low-energy constants and predictions for the two KN σ-terms and the strange contribution to the nucleon mass are made. The lack of convergence in the chiral expansions of these quantities when
more » ... quantities when regularized dimensionally is overcome in the cutoff scheme. The σ-term shifts to the pertinent Cheng-Dashen points are calculated. We also include the spin-3/2 decuplet in the effective theory. 1
doi:10.1007/s100529901054 fatcat:dr6xk2j2zbbqlhhnwy4hzksnsi