HNPS 2023

Recently, appreciably sensitive experiments operating in frontier muon facilities at J-PARC in Tokio, PSI in Switzerland, Fermilab in USA, RCNP in Osaka, etc., provide ultra-highprecision measurements in muon physics for open problems in muon-nucleus processes and purely leptonic atomic systems. A plethora of such processes are well analyzed and described by theories falling within (SM) and beyond the Standard Model (BSM) of the electroweak interactions and they constitute promising tests of the quantum electrodynamics (QED) and the BSM physical theories. Up to the present, for example, the muon-nucleus experiments (ordinary muon capture on nuclei, muon hyperfine spectroscopy, muonic-atoms, etc.) played essential role in understanding atomic, nuclear and particle physics.

Our main aim is to provide systematic predictions coming out of accurate numerical solutions of the fundamental differential equations (Dirac-Coulomb-Breit, Dirac-BreitDarwin, etc.) entering the description of structure and reactions appearing in muonic atoms (nuclear muon capture, muon to e− (or to e+) conversion in nuclei, etc.) as well as in exotic purely leptonic atoms, i.e. Muonium (μ+, e−), Muonium ion (μ+, e−e−), etc., promising tests of QED and BSM theories (e.g. testing of fundamental physical laws as the lepton number conservation in experiments searching for Muonium to anti-Muonium transition).