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arXiv · 1511.09089

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

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

Lattice QCD calculations with chiral fermions of the $π$N sigma term $σ_{πN}$ and strangeness sigma term $σ_{sN}$ 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 $σ_{πN}=45.9(7.4)(2.8)$ MeV, with the disconnected insertion part contributing 20(12)(4)\%, and $σ_{sN}=40.2(11.7)(3.5)$ MeV, which is somewhat smaller than $σ_{πN}$. The ratio of the strange/light scalar matrix elements is $y$ = 0.09(3)(1).

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Yi-Bo Yang, Andrei Alexandru, Terrence Draper, Jian Liang, Keh-Fei Liu. 2016-08-25. $π$N and strangeness sigma terms at the physical point with chiral fermions. https://doi.org/10.1103/physrevd.94.054503

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