# Predicting multi-hadron electroweak processes from the QCD path integral

- Institution: CERN
- Department: Theory Colloquia
- Speaker: Max Hansen
- Year: 2025
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3022281)
- Licence: [CERN](http://copyright.web.cern.ch)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

I will discuss recent progress and open challenges in computing multi-hadron electroweak amplitudes from lattice QCD, a Euclidean, finite-volume, discretised formulation of quantum chromodynamics. Starting from the underlying quarks and gluons, QCD predicts a spectrum of hadrons—such as the pion, kaon, and D meson—whose masses and matrix elements can now be computed with sub-percent precision using numerical lattice QCD. Looking beyond this, an important frontier involves scattering processes with multiple hadrons, including πK → πK, ππK, electroweak transitions such as πγ → ππ, K → ππ, D → ππ, and B → K*, and neutral-meson mixing amplitudes, as well as other long-distance matrix elements. Such observables are essential for interpreting experiments in flavour physics and testing the Standard Model. In this colloquium, I will aim to outline the key theoretical challenges in such calculations, review the methods developed to address them, and highlight a selection of recent results.

This talk is part also of the Charming Lattice QCD at CERN 2025 workshop

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## Lectures

1. [Predicting multi-hadron electroweak processes from the QCD path integral](https://invisiblenetwork.ai/learn/cern/3022281/ad1982c8c3d0), 1 h (CERN's player)