Publications
Publication Information
| Title | Baryon sigma terms in SU(3) BChPT x 1/Nc |
| Authors | Jose Goity |
| JLAB number | JLAB-THY-19-2915 |
| LANL number | arXiv:1904.07112 |
| Other number | DOE/OR/23177-4668 |
| Document Type(s) | (Meeting) |
| Associated with EIC: | No |
| Supported by Jefferson Lab LDRD Funding: | No |
| Funding Source: | Nuclear Physics (NP) |
| Other Funding: | NSF |
|
Meeting Invited Talk Paper compiled for CD18 Proceedings PoS CD2018 Edited By Proceedings of Science (2020) Refereed Page(s) 061 | |
| Publication Abstract: | ChPT and the $1/N_c$ expansion provide systematic frameworks for the strong interactions at low energy. A combined framework of both expansions has been developed and applied for baryons with three light-quark-flavors. The small scale expansion of the combined approach is identified as the $\xi$-expansion, in which the power counting of the expansions is linked according to $\ord{p}=\ord{1/N_c}=\ord{\xi}$. The physical baryon masses as well as lattice QCD baryon masses for different quark mass masses are analyzed to $\ord{\xi^3}$ in that framework. $\sigma$ terms are addressed using the Feynman Hellmann theorem. For the nucleon, a useful connection between the deviation of the Gell-Mann-Okubo relation and the $\sigma$ term $\sigma_{8N}$ associated with the scalar density $\bar u u+\bar d d-2\bar s s$ is identified. In particular, the deviation from the tree level relation $\sigma_{8N}=\frac 13(2 m_N-m_\Sigma-m_\Xi)$, which gives rise to the so called $\sigma$-term puzzle, is studied in the $\xi$-expansion. A large correction non-analytic in $\xi$ results for that relation, making plausible the resolution of the puzzle. Issues with the determination of the strangeness $\sigma$ terms are discussed, emphasizing the need for lattice calculations at smaller $m_s$ for better understanding the range of validity of the effective theory. The analysis presented here leads to $\sigma_{\pi N}=69(10)$~MeV and $\sigma_{\pi \Delta}=60(10)$~MeV. |
| Experiment Numbers: | other |
| Group: | THEORY CENTER |
| Document: | |
| DOI: | https://doi.org/10.22323/1.317.0061 |
| Accepted Manuscript: | CD2018_061.pdf |
| Supporting Documents: | |
| Supporting Datasets: | |