Sigma term and strangeness content of octet baryons

S. Dürr, Z. Fodor, T. Hemmert, C. Hoelbling, J. Frison, S. D. Katz, S. Krieg, T. Kurth, L. Lellouch, T. Lippert, A. Portelli, A. Ramos, A. Schäfer, K. K. Szabó

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

By using lattice QCD computations we determine the sigma terms and strangeness content of all octet baryons by means of an application of the Hellmann-Feynman theorem. In addition to polynomial and rational expressions for the quark-mass dependence of octet members, we use SU(3) covariant baryon chiral perturbation theory to perform the extrapolation to the physical up and down quark masses. Our Nf=2+1 lattice ensembles include pion masses down to about 190 MeV in large volumes (MπL≳4), and three values of the lattice spacing. Our main results are the nucleon sigma term σπN=39(4)(-7+18) and the strangeness content yN=0.20(7)(-17+13). Under the assumption of validity of covariant baryon χPT in our range of masses one finds yN=0.276(77)(-62+90).
Original languageEnglish
Pages (from-to)14509
JournalPhysical Review D, particles, fields, gravitation, and cosmology
Issue number1
Publication statusPublished - 1 Jan 2012

Keywords / Materials (for Non-textual outputs)

  • Lattice QCD calculations
  • Chiral Lagrangians
  • Protons and neutrons


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