Scalar resonances in the hadronic light-by-light contribution to the muon (g-2): an holographic approach

by Mr Luigi Cappiello (Naples U.)

Thursday 24 Feb 2022, 12:00 → 13:00 Europe/Madrid

IFAE Virtual Seminar Room (IFAE)

Recently,  the contribution of scalar mesons to the hadronic light-by-light piece of the muon anomalous magnetic moment, was eveluated using a warped five-dimensional model and holographic methods.
The contribution of the lightest, sub-GeV scalars  $\sigma(500)$, $a_0(980)$ and $f_0(980)$ were assessed together with their associated towers of excited states, which the model generates automatically. The results pointed at a clearly negative contribution, overwhelmingly dominated by
the  $\sigma(500)$ meson, that we estimated at  $a_{\mu}(\textrm{scalars}) = -9(2)\cdot 10^{-11}$ in very good agreement with the most recent determinations from dispersive analyses QCD approach.
In this seminar, after a short summary on the status of the hadronic
contributions and in particular of the HLbL contribution to $a_{\mu}$, we present a gentle introduction to the holographic model and methods used in our calculation, emphasizing the extraction of the short distance corrections and the similarities and differencies between the scalars and the Goldstone boson + axial vectors case, considered in previous papers,
regarding the matching with short distance constraints of perturbative QCD.

CappielloBarcelona2022.pdf Video Recording