A procedure for selection of J/ψ → ee decays registered by the CBM set-up is presented. The key problem is a fast and reliable electron/positron identification using the energy losses of charged particles in the Transition Radiation Detector. An analysis of the application features and a comparison of power of two methods to solve this task are given: an artificial neuron network (ANN) and a ω goodness-of-fit criterion. The choice of the approach based n on the ω goodness-of-fit criterion is explained.