RN-EMP-2015-006

This note reports on the latest status of the feasibility studies for the measurement
of time-like, proton electromagnetic form factors (TL EM FFs) at the PANDA
experiment at FAIR. Electromagnetic FFs are fundamental quantities parameterizing
the electric and magnetic structure of hadrons. In the time-like region proton
FFs can be accessed experimentally with the aid of annihilation processes of the type
pbar p -> l+l− (l = e, μ), assuming that the interaction takes place through the exchange of
one virtual photon. The individual determination of the time-like electric and magnetic
proton FFs was limited in the past by the low luminosity available at colliders. In frame
of the PANDARoot software, which encompasses full detector simulation and event reconstruction,
the statistical precision at which the proton FFs will be determined at
PANDA is estimated for the signal channel pbar p -> μ+μ-. The signal identification and suppression
of the main background process (pbar p -> π+π−) is studied. Different methods have
been used to generate and analyse the processes of interest. The results show that TL EM FFs can be measured at PANDA with unprecedented statistical accuracy.