Abstract
The High Acceptance Di-Electron Spectrometer (HADES) at the GSI Helmholtzzentrum für Schwerionenforschung investigates dilepton and strangeness production in elementary and heavy-ion collisions. In April - May 2012 HADES recorded 7 billion Au+Au events at a beam energy of 1.23 GeV/u with the highest multiplicities measured so far. The track reconstruction and particle identification in the high track density environment are challenging. The most important detector component for lepton identification is the Ring Imaging Cherenkov detector. Its main purpose is the separation of electrons and positrons from large background of charged hadrons produced in heavy-ion collisions. In order to improve lepton identification this backtracking algorithm was developed. In this contribution we will show the results of the algorithm compared to the currently applied method for e+/-identification. Efficiency and purity of a reconstructed e+/- sample will be discussed as well.
Highlights
The backtracking algorithm to simulated and real data has shown that the number of pads per ring and maxima per ring are the most powerful to distinguish between leptons and hadrons
Backtracking was tested for close pair rejection in simulated data
Backtracking information is useful to identify the close partner of a lepton in order to reject close pairs
Summary
The backtracking algorithm to simulated and real data has shown that the number of pads per ring and maxima per ring are the most powerful to distinguish between leptons and hadrons. Itself are called maxima and are summed up as well. A ring quality based on the difference between the actual photon hit and the most probable hit position is calculated.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
