Backsplash testbeam results for the SPD subdetector of LHCb

The Scintillator Pad Detector (SPD) of the LHCb experiment [1] is positioned just before the preshower subdetector (PS), in front of the electromagnetic calorimeter (ECAL). It has been designed to complete the calorimeter information performing an e/γ identification for the experiment level-0 trigger system. Backscattered particles produced in the PS and the ECAL might introduce inefficiencies in the e/γ separation performed by the SPD. A testbeam with electrons and pions, at different energies, has allowed an experimental study of this effect.