Muon and electron reconstruction efficiency at LHCb

The leptons that are produced in the LHCb (especially the electrons), are "suffering" from bremsstrahlung radiation. This is caused by their interactions with the surrounding material and magnetic field. This leads to decrease of their momentum and scattering, and therefore to fewer tracks into our detectors. As a result, the reconstruction of these particles becomes more difficult, and in some cases impossible. In this small project we study how the electron and muon reconstruction efficiency changes with respect to the kinematics of the particles, the various kinematic cuts and the track types. When measuring the efficiency of data, a tag-and-probe method is used with the decay B+ → J/psi (→ e-e+) K+, where one electron is the tag and the other the probe. The measurement is performed in bins of p, pt and eta. In order to extract as much useful information as possible, without having low statistics in each bin, the bin size is optimized by studying the efficiency variation in simulation samples.