$Ï$N and strangeness sigma terms at the physical point with chiral fermions

Yi-Bo Yang; Andrei Alexandru; Terrence Draper; Jian Liang; Keh-Fei Liu

doi:10.1103/PhysRevD.94.054503

paper

$I ¨ $ N and strangeness sigma terms at the physical point with chiral fermions

arXiv:1511.09089 · doi:10.1103/PhysRevD.94.054503

Abstract

Lattice QCD calculations with chiral fermions of the $I ¨ $ N sigma term $I ¨ _{I ¨ N}$ and strangeness sigma term $I ¨ _{s N}$ including chiral interpolation with continuum and volume corrections are provided in this work, with the excited-state contaminations subtracted properly. We calculate the scalar matrix element for the light/strange quark directly and find $I ¨ _{I ¨ N} = 45.9 (7.4) (2.8)$ MeV, with the disconnected insertion part contributing 20(12)(4)\%, and $I ¨ _{s N} = 40.2 (11.7) (3.5)$ MeV, which is somewhat smaller than $I ¨ _{I ¨ N}$ . The ratio of the strange/light scalar matrix elements is $y$ = 0.09(3)(1).

7 pages, 5 figures, expanded version accepted for publication in PRD

I¨N and strangeness sigma terms at the physical point with chiral fermions

Abstract

$I ¨ $ N and strangeness sigma terms at the physical point with chiral fermions