Precision Measurement of the e?e??p?p?p Cross Section Using Initial-State Radiation

This book presents a high-precision measurement of the cross section for electron-positron annihilation into three pions (π? π? π ) using the initial-state radiation (ISR) method with Belle II data, offering key input for the hadronic vacuum polarization contribution to the muon. It addresses longstanding tensions in hadronic cross-section data and contributes to the refinement of the Standard Mod...