Seminarium Fizyki Wielkich Energii

The Backing Calorimeter (BAC) in the ZEUS experiment at the HERA accelerator was designed to supplement the energy measurement of jets leaking out of the central Uranium Calorimeter. BAC was manufactured and operated for 15 years of HERA activity by physicists, engineers and technicians from the Faculty of Physics at the University of Warsaw and the AGH University of Science and Technology in Kraków. It was the biggest detector constructed so far in the history of Polish contribution to the HEP experiments. For HERA-II period it was converted into a fully operational muon detector equipped with three-level muon trigger based on positional (hit) and energy readout. During the seminar the performance of the BAC calorimeter as a muon detector will be presented focusing on its contribution to the measurements of heavy vector mesons production observed in the decay channels involving muons.