Precision Measurement of the Hadronic Contribution to the Muon Anomalous Magnetic Moment

Abstract

We report on a precision measurement of the cross section for the reaction $e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$ in the mass range $0.30<M_{\ddot{I}€\ddot{I}€}<1.00$ GeV with the initial state radiation (ISR) method, using 817 pb${}^{-1}$ of data at $e^{+}{e}^{-}$ center-of-mass energies near 3.77 GeV and 586 pb${}^{-1}$ of data at $e^{+}{e}^{-}$ center-of-mass energies near 4.17 GeV, collected with the CLEO-c detector at the CESR $e^{+}{e}^{-}$ collider at Cornell University. The integrated cross sections in the range $0.30<M_{\ddot{I}€\ddot{I}€}<1.00$ GeV for the process $e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$ are determined with a statistical uncertainty of $0.7\%$ and a systematic uncertainty of $1.5\%$. The leading-order hadronic contribution to the muon anomalous magnetic moment calculated using these measured $e^{+}{e}^{-}\to \ddot{I}{€}^{+}\ddot{I}{€}^{-}$ cross sections in the range $M_{\ddot{I}€\ddot{I}€}=0.30$ to 1.00 GeV is calculated to be $(500.4\pm 3.6(\mathrm{stat})\pm 7.5(\mathrm{syst}))\times 10^{-10}$.

14 pages, 13 figures, submitted to PRD