Physicists Solve a Muon Mystery. Now, Old Results Don't Add Up

New lattice calculations suggest the long-standing muon g-2 anomaly is resolved by known physics, yet this contradicts older data-driven methods. This clash implies potential errors in past electron-positron collision experiments at facilities like VEPP-2000, reigniting the search for unknown particles or experimental inconsistencies.
The measurement of muon g–2 is a proxy for saying how many particles exist in the universe.