Lepton reconstruction in the ENUBET tagger

The ENUBET project aims at demonstrating the feasibility of a monitored neutrino beam in which the measurement of associated charged leptons in the instrumented decay region of a conventional beam is used to constrain the neutrino flux to unprecedented precision ($\mathcal{O}$(1\%)). Large angle muons and positrons from kaon decays are detected on the decay tunnel walls equipped with a sampling calorimeter with longitudinal, radial and azimuthal segmentation. After a brief description of the ENUBET beamline and of the detectors employed in the lepton tagger, the analysis chain for the event reconstruction, the background suppression and the identification of positrons and muons will be described.