report · OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information) · 1992
Central calorimeter gamma detection efficiency
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Abstract
In this memo they present some results on the Central Calorimeter {gamma} detection efficiency in the low energy region. Briefly, the software energy threshold to start a cluster has to be decided on the basis of the detection efficiency because using a too low value increases the amount of spurious clusters and on the other hand a too high threshold tends to reject good clusters. They used a sample of reconstructed {pi}{sup 0}{pi}{sup 0} events at E{sub CM} = 2.985 GeV with a cluster threshold at 20 MeV and 5 MeV for the central block. For each event they selected the least energetic {gamma} among the fitted values. The energy distribution of the low energy tail is shown in Fig. 1.a. The expected {gamma} energy distribution has been simulated by Monte Carlo. Events p{bar p} {yields} {pi}{sup 0}{pi}{sup 0} were generated starting with the experimental center of mass angular distribution. They selected events with 4{gamma} in the Central Calorimeter acceptance and considered the least energetic {gamma} among the four. The generated distribution is shown in Fig. 1.b. The detection efficiency as a function of E{sub {gamma}} can be computed comparing the experimental softest {gamma} energy distribution to the expected from Monte Carlo. The normalization can be done in several ways: (a) assuming a 100% detection efficiency for {gamma} with energy within 200 and 400 MeV; (b) normalizing the total number of reconstructed events. The two methods gave normalization constants differing by less than 1%. In Fig. 2 they show the detection efficiency plot as a function of the {gamma} energy. The curve is rather sharp and at around 30 MeV the efficiency saturates at 1. They notice that efficiency is slightly higher than 1., and they explain the anomalous behavior as an indication of a contribution of background events, which tends to be higher with soft {gamma}'s.
Cite this paper
Lombardo, M. P., & Marchetto, F. (1992). Central calorimeter gamma detection efficiency. OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information). https://doi.org/10.2172/875507
Lombardo, M. P., and F. Marchetto. “Central calorimeter gamma detection efficiency.” OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information), 1992, https://doi.org/10.2172/875507.
Lombardo, M. P., and F. Marchetto. 1992. “Central calorimeter gamma detection efficiency.” OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information). https://doi.org/10.2172/875507.
Lombardo, M.P. and Marchetto, F. (1992) ‘Central calorimeter gamma detection efficiency’, OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information). Available at: https://doi.org/10.2172/875507.
@article{lombardo1992central,
title = {{Central calorimeter gamma detection efficiency}},
author = {Lombardo, M. P. and Marchetto, F.},
journal = {OSTI OAI (U.S. Department of Energy Office of Scientific and Technical Information)},
year = {1992},
doi = {10.2172/875507}
}Made from the index record. Check names, capitalisation and page numbers against the paper. Need another style? AI for Research has over 10,000.