Measurement of the pion form factor at BESIII in the rho-peak region relevant for (g — 2)μ

7th International Conference on Beauty, Charm, and Hyperons in Hadronic Interactions

Redmer, C.F.^1

Institut für Kernphysik, Johannes Gutenberg-Universität Mainz, J.-J.-Becher-Weg 45, Mainz

55128, Germany^1

关键词: Anomalous magnetic moments;    Energy ranges;    Form factors;    Initial state radiations;    Measurements of;    Systematic uncertainties;    The standard model;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/770/1/012036/pdf
DOI  :  10.1088/1742-6596/770/1/012036

来源: IOP

【 摘 要 】

Measurements of hadronic cross sections in e+e- collisions are an important input for the Standard Model calculations of the hadronic contribution to the anomalous magnetic moment of the muon, (g - 2)μ. We present a new measurement of the cross section e+e-→ π+π-, the pion form factor, which dominates the hadronic contribution. Using the method of initial state radiation, 2.93 fb-1of data taken with the BESIII detector at the ψ (3770) peak have been evaluated to determine the cross section in the energy range between 600 and 900 MeV with a systematic uncertainty of 0.9%. The new BESIII data are compared to previous measurements by KLOE and BaBar, and their impact on (g - 2)μ is discussed.