Pion-nucleon scattering and the nucleon sigma term in an extended sigma model

Details Pion-nucleon scattering and the nucleon sigma term in an extended sigma model Pion-nucleon scattering and the nucleon sigma term in an extended sigma model

1999-11-11

arxiv.org/abs/hep-ph/9911320v1

Phys.Rev.C61:025205,2000

Physics

High Energy Physics

High Energy Physics - Phenomenology

21 pages, 1 postscript figure, submitted to Phys. Rev

Scientific paper

10.1103/PhysRevC.61.025205

A modified linear sigma model that allows for $g_A = 1.26$ by addition of vector and pseudovector $\pi N$ coupling terms was discussed by Bjorken and Nauenberg and by Lee. In this extended linear sigma model the elastic $\pi $N scattering amplitudes satisfy the relevant chiral low-energy theorems, such as the Weinberg-Tomozawa relation for the isovector scattering length and in some cases Adler's "consistency condition". The agreement of the isospin symmetric $\pi N$ scattering length with experiment is substantially improved in this extended sigma model as compared with the original one. We show that the nucleon sigma term ($\Sigma_N$) in the linear- and the extended sigma models with three different kinds of chiral symmetry breaking terms are identical. Within the tree approximation the formal operator expression for the $\Sigma_N$ term and the value extracted from the $\pi N$ scattering matrix coincide. Large values of $\Sigma_N$ are easily obtained without any $s\bar s$ content of the nucleon. Using chiral rotations the Lagrangian of this extended sigma model reproduces the lowest-order $\pi N$ chiral perturbation theory Lagrangian.

Affiliated with

Also associated with

No associations

Rating

Pion-nucleon scattering and the nucleon sigma term in an extended sigma model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Pion-nucleon scattering and the nucleon sigma term in an extended sigma model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pion-nucleon scattering and the nucleon sigma term in an extended sigma model will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-587159