The ρ and K* resonances using lattice QCD at physical quark masses

by Nelson Lachini (Cambridge U.)

Monday 2 Dec 2024, 16:00 → 17:00 Europe/Berlin

ENC-D308

The ρ and K* resonances play a central role in Standard Model tests due to their decays into ππ and Kπ states via the strong interaction, respectively. In this talk, we present our study of the ρ and K* resonances employing physical quark masses and review the required theoretical and methodological framework used for analysing scattering from lattice QCD observables. In particular, we study finite-volume energies in various moving frames and obtain phase-shift parameterisations through the Lüscher formalism. The resonance poles on the ππ and Kπ scattering amplitudes are then obtained via an analytical continuation into the complex plane. We estimate the systematic effects due to analysis choices by developing a data-driven procedure based on the Akaike information criterion. We conclude by comparing our results to the current PDG estimates, and comment on other relevant systematic effects and future calculations.