Progetti di ricerca

Our understanding of Nature depends on our ability to validate, with experiments, theoretical predictions for observable quantities. The Standard Model of particles describes three of the four known fundamental forces in Nature and has been extensively tested at collider experiments over the last… Leggi tutto decades. Strong interactions are one of its components and are characterized by so-called non-perturbative phenomena. Their low-energy contribution to quantities measurable in experiments can be predicted from first principles by discretizing QCD on a four-dimensional lattice and simulate it with Monte Carlo methods on world-class HPC facilities. To test the Standard Model to unprecedented precision the interplay between strong and electromagnetic forces must be considered, and the goal of this project is the prediction of the so-called isospin-breaking corrections for several phenomenologically relevant quantities, from first principles Lattice QCD+QED simulations. The primary focus is on the anomalous magnetic moment of the muon, a promising candidate for unveiling new fundamental phenomena beyond our current understanding, but this project opens the door to the precise assessment of isospin-breaking effects also in hadronic tau decays or meson leptonic decays.

Exploring the standard model of particle physics and finding new physics beyond is in many cases limited by the lack of high-precision knowledge of low-energy QCD effects. The only known systematically improvable method to compute such effects from first principles is lattice… Leggi tutto QCD. For crucial topics such as the muon g-2, heavy-quark flavour physics, and the study of structure functions, the systematic uncertainty associated with the continuum limit of lattice QCD poses one of the most difficult challenges. For the muon g-2 uncertainties associated with finite simulation volume are also crucial. Building on our successful project last year, we propose to generate the finest-yet dynamical lattice QCD gauge ensemble using chiral symmetric domain wall fermions at physical pion mass, the first Nf=2+1+1 domain-wall ensemble at physical pion mass, as well as a g- 2 program in an 11fm box at physical pion mass. This effort is only possible using the scale of resources made available in the EuroHPC JU Extreme Scale Access call. The results of this proposal will have immediate impact on a high-precision calculation of the hadronic vacuum polarization contribution to clarify emerging tensions for the muon g-2 and have long-term benefits for a wide range of crucial observables.