The hadronic contribution to the muon g-2
from hadron production in initial state radiation
at the e+e- collider DANE
Dipartimento di Fisica dell'Università di Lecce and INFN, Sezione di Lecce, via Arnesano I-73100 Lecce, Italy
Received: 27 April 1998 / Published online: 26 August 1998
A relevant reduction of the theoretical uncertainty on the muon anomalous magnetic moment, dominated by the error on the leading hadronic contribution , would come from a new precise measurement of the cross section of e+e- annihilation into hadrons () below 1 GeV. An experimental approach to the evaluation of the dispersion integral defining is proposed here as an alternative to the conventional method based on the interpolation of different measurements of performed with a center of mass energy scan. The wide occurrence of hadron production, at variable q2, in the initial state radiation (ISR) events at the high luminosity -factory DANE suggests to redefine the dispersion integral in terms of the differential cross section for . The feasibility of such measurement, which can be performed without the need of dedicated run conditions and with the benefit of the full luminosity of the machine, is discussed. The required precision is shown to be easily achieved thanks to the resolutions and performances of the KLOE detector.