Analysis of one and two track events in scintillation counters


In general, the aim of this work is to analyse the probability of distinguishing between two cases when one or two particles are passing through a scintillator. The main information about the mechanism of losing energy by the particles and also about the distribution of their energy loss are contained in the first chapter. In the second one the accordance of the experimental data to the Bethe-Bloch formula in the range up to 2 GeV is examined and in the third part the problem of the identification of very close tracks is considered.
'Close' means that the distance of two trajectories is so small that the drift chambers cannot resolve them.
For measurements of the pp->ppX reactions very close to threshold the momenta of the protons are comparable and their trajectories are very close. With the drift chambers a resolution of two tracks as close as 3 mm is achieved.
For closer tracks a separation via the drift chamber reconstruction is not possible, these are identified as a single track. But such events could be analysed if the particle multiplicity in the scintillator is known, the single track could be interpreted as two tracks with identical momenta and the missing mass of the system X could be calculated.
A multiplicity signal is in principle given by the energy loss in the scintillator.
Due to the energy loss distribution a clear separation of the multiplicity 'one' and 'two' is not efficient with a single scintillation dE/dx signal. The analysis of several scintillator elements is needed.

Master of Science Thesis in PostScript-Format (~1.6MB)