Speaker
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 boxes, 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, we report on the 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 extract the moments for a range of $Q^2$ values. A comparison to the Gross-Llewellyn Smith sum rule is given. Additionally, we estimate the power corrections by studying the $Q^2$ dependence of the moments.
| Topical area | Structure of Hadrons and Nuclei |
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