Nucleon Spin Sum Rules and Spin Polarizabilities at low $Q^2$

Conference · Tue Jul 30 04:00:00 EDT 2024 · Proceedings of 25th International Symposium on Spin Physics — PoS(SPIN2023)

DOI:https://doi.org/10.22323/1.456.0175· OSTI ID:2560856

Deur, Alexandre

We report on recently published experimental studies on spin sum rules, namely the generalized Gerasimov-Drell-Hearn, Bjorken, Burkhardt-Cottingham, Schwinger, and generalized spin polarizability sum rules. The data were taken at Jefferson Lab in Halls A and B by experiments E97-110 and EG4, respectively. They covered the very low $Q^2$ domain, down to $Q^2$$$$\simeq$$0.02 GeV$^2$, where Chiral Effective Field Theory ($$\chi$$EFT) predictions should be valid. While some of the obervables agree with the state-of-the-art $$\chi$$EFT predictions, others are in tensions, including the Longitudinal-Transverse interference polarizability $$\delta_{\rm LT}^n(Q^2)$$ for which $$\chi$$EFT prediction was expected to be robust. This suggests that $$\chi$$EFT does not yet consistently describes nucleon spin observables, even in the very low $Q^2$ domain covered by the experiments.

• Research Organization: Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Nuclear Physics (NP)
• DOE Contract Number: AC05-06OR23177
• OSTI ID: 2560856
• Report Number(s): JLAB-PHY-24-3983; DOE/OR/23177-7370; arXiv:2402.04525
• Conference Information: Journal Name: Proceedings of 25th International Symposium on Spin Physics — PoS(SPIN2023)
• Country of Publication: United States
• Language: English