Speaker
Dr
Umberto Marconi
(BO)
Description
The precision measurement of the anomalous magnetic moment of the muon presently exhibits a 3.5σ discrepancy with the Standard Model (SM) prediction. In the next few years this measurement will reach an even higher precision at Fermilab and J-PARC. While the QED and electroweak contributions to the muon g-2 can be determined very precisely, the leading hadronic (HLO) correction is affected by a large uncertainty which dominates the error of the SM prediction. We propose a novel approach to determine the HLO contribution to the muon g-2 based on the measurement of the effective electromagnetic coupling in the space-like region at low-momentum transfer. We will discuss the possibility of performing this measurement at CERN, by means of a very precise determination of the muon-electron elastic differential cross-section, exploiting the scattering of 150 GeV muons (currently available at CERN's North area) on atomic electrons of a low-Z target. We will describe the experimental challenges posed by this measurement and by a detector able to keep the systematic effects at the required level of 10 ppm. This measurement will provide an independent determination of the HLO contribution to the muon g-2 competitive with the time-like dispersive approach, thus consolidating the SM prediction. It will therefore allow a firmer interpretation of the measurements of the future muon g-2 experiments at Fermilab and J-PARC.
Primary author
Dr
Umberto Marconi
(BO)
