EPJ Web of Conferences
Volume 66, 2014INPC 2013 – International Nuclear Physics Conference
|Number of page(s)||4|
|Published online||20 March 2014|
The nucleon mass and pion-nucleon sigma term from a chiral analysis of Nf = 2 lattice QCD world data
1 Instituto de Física Corpuscular (IFIC), Centro Mixto Universidad de Valencia-CSIC, Valencia, Spain
2 Departamento de Física Teórica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Valencia, Spain
3 Department of Physics and Astronomy, University of Sussex, Brighton, UK
a e-mail: firstname.lastname@example.org
Published online: 20 March 2014
We investigate the pion-mass dependence of the nucleon mass within the covariant SU(2) baryon chiral perturbation theory up to order p4 with and without explicit Δ (1232) degrees of freedom. We fit lattice QCD data from several collaborations for 2 and 2+1 flavor ensembles. Here, we emphasize our Nf = 2 study where the inclusion the Δ (1232) contributions stabilizes the fits. We correct for finite volume and spacing effects, set independently the lattice QCD scale by a Sommer-scale of r0 = 0.493(23) fm and also include one σπN lQCD data point at Mπ ≈ 290 MeV. We obtain low-energy constants of natural size which are compatible with the rather linear pion-mass dependence observed in lattice QCD. We report a value of σπN = 41(5)(4) MeV for the 2 flavor case and σπN = 52(3)(8) MeV for 2+1 flavors.
© Owned by the authors, published by EDP Sciences, 2014
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 2.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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