Speaker
Description
The anomalous magnetic moment g-2 of the muon is a precision measurement which
exhibits one of the largest deviation between theory and experiment. In the
next years it will be measured at Fermilab and J-PARC with even higher precision
.
The hadronic contribution to the muon g-2,$a^{HLO}_{\mu}$, is the most
important effect after the pure QED contributions. It is however affected by a
large uncertainty which dominates the error on the theoretical prediction in
the Standard Model.
Therefore it is extremely important to get independent measurement of this
hadronic contribution to reduce its uncertainty.
We propose a novel approach to determine the leading hadronic corrections,
consisting in measuring the effective electromagnetic coupling in the
space-like region at low momentum transfer in the elastic scattering of
high energy muons from atomic electrons.
The high energy muon beam M2 in the CERN North Area is adequate to perform
such a measurement. The challenge of this project MUonE is in the accuracy
which must be achieved, both statistical and systematic. This measurement will
allow the determination of $a^{HLO}_{\mu}$ alternative to the
present results obtained with the dispersive approach via time-like data.
In this talk, accent will be put on the results of testbeams performed in 2017 a
nd 2018 at CERN.
