Measuring the leading hadronic contribution to the muon g2 via μ e scattering
Abstract
We propose a new experiment to measure the running of the electromagnetic coupling constant in the spacelike region by scattering highenergy muons on atomic electrons of a low Z target through the elastic process μ e → μ e. The differential cross section of this process, measured as a function of the squared momentum transfer t=q^2<0, provides direct sensitivity to the leadingorder hadronic contribution to the muon anomaly a^{HLO}_{μ }. By using a muon beam of 150 GeV, with an average rate of ̃ 1.3 × 10^7 muon/s, currently available at the CERN North Area, a statistical uncertainty of ̃ 0.3% can be achieved on a^{HLO}_{μ } after two years of data taking. The direct measurement of a^{HLO}_{μ } via μ e scattering will provide an independent determination, competitive with the timelike dispersive approach, and consolidate the theoretical prediction for the muon g2 in the Standard Model. It will allow therefore a firmer interpretation of the measurements of the future muon g2 experiments at Fermilab and JPARC.
 Publication:

European Physical Journal C
 Pub Date:
 March 2017
 DOI:
 10.1140/epjc/s100520174633z
 arXiv:
 arXiv:1609.08987
 Bibcode:
 2017EPJC...77..139A
 Keywords:

 High Energy Physics  Experiment;
 High Energy Physics  Phenomenology
 EPrint:
 8 pages, 4 figures