26 July 2026 to 1 August 2026
University of Maryland, College Park
US/Eastern timezone

Direct Determination of the Sigma Terms of the Baryon Octet from $N_\mathrm{f} = 2+1$ Lattice QCD with Wilson fermions

30 Jul 2026, 16:30
20m
Benjamin Banneker A (Adele H. Stamp Student Union)

Benjamin Banneker A

Adele H. Stamp Student Union

3972 Campus Dr, College Park, MD 20742
Contributed talk Structure of hadrons and nuclei Structure of hadrons and nuclei

Speaker

Pia Leonie Jones Petrak (JLab)

Description

Sigma terms are of fundamental interest as measures of the quark mass contributions to the mass of a given baryon. As the key input for neutrino and nucleon cross-sections, the nucleon sigma terms are relevant for dark matter predictions. Further, for the nucleon-pion sigma a long standing discrepancy between Lattice QCD and phenomenology persists. By performing a direct determination of the full baryon octet for the first time in a combined analysis on 34 CLS ensembles, we provide new insight into this disparity. I will present how we tackle the excited state contamination; we investigate the effect of different multi-state fits on the sigma terms and assess systematics. The baryon octet sigma terms are then simultaneously extrapolated to the physical point taking the quark mass dependence, lattice spacing and finite volume effects into account. I will conclude by discussing the final steps to work out the error budget in detail, including model averaging.

Author

Co-authors

Gunnar Bali (Universität Regensburg) Jochen Heitger (University of Münster, ITP) Sara Collins (University of Regensburg) Simon Weishaeupl (University of Regensburg)

Presentation materials