DOI 10.1007/s100529901054
Sigma-terms in heavy baryon chiral perturbation theory revisited
B. Borasoy
Department of Physics and Astronomy,
University of Massachusetts,
Amherst, MA 01003, USA
(e-mail: borasoy@het.phast.umass.edu)
Received: 21 July 1998 / Revised version: 31 August 1998 / Published online: 25 January 1999
Abstract
The 
-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 
are used to perform a least-squares fit
to the three appearing low-energy constants and predictions for the
two KN -terms and the strange contribution to the nucleon mass
are made. The lack of convergence in the chiral expansions of
these quantities when regularized dimensionally is overcome in the
cutoff scheme.
The -term shifts to the pertinent Cheng-Dashen points are
calculated.
We also include the spin-3/2 decuplet in the effective theory.
Copyright Springer-Verlag
