42nd International Symposium on Lattice Field Theory (Lattice 2025)

Hadronic contributions to $\alpha(Q^2)$ and $\sin^2\theta_W(Q^2)$ from spectral reconstruction on the lattice.

4 Nov 2025, 15:10

20m

D406

Talk Hadronic contribution to the magnetic moment of muon

Speaker

Adrián del Pino Rubio (University of Zaragoza)

Description

We present progress towards a new determination of the hadronic vacuum polarization (HVP) function $\Pi(Q^2)$ relevant for the running of the electromagnetic coupling and the electroweak mixing angle. In the conventional time–momentum representation, strong correlations induced by the kernel prevent reliable continuum extrapolations. To address this issue, we reconstruct smeared spectral densities from Euclidean correlators using the Hansen–Lupo–Tantalo (HLT) method. The unsmeared spectral density is then obtained by extrapolating in the smearing width, and results from several ensembles with different lattice spacings are combined to perform a controlled continuum limit.
We present first applications of this strategy and discuss future directions for obtaining continuum results for $\Pi(Q^2)$ with competitive precision for electroweak observables.