XVIth Quark Confinement and the Hadron Spectrum

The parity-odd structure function of the nucleon from the Compton amplitude in lattice QCD

22 Aug 2024, 15:00

30m

Plenary 1

Oral B: Light Quarks Light Quarks

Speaker

Dr K. Utku Can (The University of Adelaide)

Description

The dominant contribution to the theoretical uncertainty in the extracted weak parameters of the Standard Model comes from the hadronic uncertainties in the electroweak box diagrams, i.e. $\gamma -W^{\pm }/Z$ exchange diagrams. A dispersive analysis relates the box diagrams to the parity-odd structure function, $F_3$, for which the experimental data either do not exist or belong to a separate isospin channel. Therefore a first-principles calculation of $F_3$ is highly desirable.

In this contribution, I report on the CSSM/QCDSF/UKQCD Collaboration's progress in calculating the moments of the $F_3^{\gamma Z}$ structure function from the forward Compton amplitude at the SU(3) symmetric point. We focus on the first moment of $F_3^{\gamma Z}$ for a range of $Q^2$ values. We discuss the implications of our results for the electroweak box diagrams along with the possibility of a determination of the strong coupling constant via the Gross-Llewellyn Smith sum rule.

Presentation materials

can_conf24.pdf