Figure 1

Specific energy loss of the tracks ($\rm{d}\mathit{E}/\rm{d}\mathit{x}$) in the TPC versus rigidity for negative and positive particles Lines represent the parameterization of the Bethe-Bloch formula for various particle species(the red lines correspond to (anti-)deuteron and (anti-)$\rm{^{3}He}$ nucleus) Most of the nuclei at low rigidity are produced from the material ``knock out'':to reject them, the information of the distance of closest approach of the tracks to the reconstructed primary vertex is used (see text)