Multisource Evidence for Final State Hadrons in 3.7A GeV 16O–Nucleus Interactions

In 3.7A GeV 16O interactions with emulsion nuclei, the shower particle multiplicity characteristics are investigated. Data are presented in terms of the number of emitted particles in both forward and backward angular zones. The dependence on the target size and emission direction is presented. The target separation of events depends on Glauber's multiple scattering theory approaches. A decay mechanism seems to be a characteristic of the backward production. This production may be during the de–excitation of the excited target nucleus, regarding the nuclear limiting fragmentation hypothesis. The forward emitted particle is due to a creation system. The target size is an effective parameter as well as the projectile size in this system, considering the geometrical concept regarded in the nuclear fireball concept. The data are simulated in the framework of the modified FRITIOF model. The multisource thermal model can predict source numbers responsible for particle production.

Features about pion production in 2.1A and 3.7AGeV 4He–nucleus interactions up to and out of kinematical limit

The shower particle multiplicity characteristics are studied in 2.1A and 3.7A GeV 4He interactions with emulsion nuclei. The dependencies on emission direction, energy, target size, and centrality are examined. The data are compared with the simulation of the modified FRITIOF model. The forward emitted pion multiplicity distributions exhibit KNO scaling. The decay or peaking shaped curves characterize the pion multiplicity distributions. The decay shape is suggested to be due to a single source contribution and the peaking one results from a multisource superposition. The forward emitted pion is created from fireball or hadronic matter. The target nucleus is the origin of the backward one, regarding the nuclear limiting fragmentation hypothesis.

Fluctuations

The energy resolution, i.e. the precision with which the energy of a showering particle can be measured, is one of the most important characteristics of a calorimeter. This resolution is determined by fluctuations in the absorption and signal formation processes. In this chapter, the different types of fluctuations that may play a role are examined, and their relative practical importance is addressed. Sources of fluctuations include fluctuations in the number of signal quanta, sampling fluctuations, fluctuations in shower leakage, as well as a variety of instrumental effects. Since the energy dependence of the different types of fluctuations is not the same, different types of fluctuations may dominate the energy resolution at low and and at high energies. An important type of fluctuations is part of the non-compensation phenomena. It concerns fluctuations in the strength of the electromagnetic component of hadronic showers. The effects of these fluctuations, which typically dominate the energy resolution for hadron and jet detection, are examined in detail. In sampling calorimeters, one particular shower particle may sometimes have catastrophic effects on the calorimeter performance. Several examples of such cases are discussed.

A Study of Pion-Nucleus Interactions in terms of Compound Particles

We report some results on the compound multiplicity distribution at 340 GeV/c π- nucleus interactions. Compound multiplicity distribution is found to depend on the target size and the distribution becomes broader. The peak of the distribution shifts towards higher values of the compound particle multiplicity. Mean compound multiplicity is found to vary linearly with grey, heavy, and shower particle multiplicity. Correlations between different particle multiplicities have been studied in detail. Dispersion of compound multiplicity distributions and its ratio with the mean value is observed to obey a linear relationship with different particle multiplicities except for shower particles where dispersion is almost independent of shower particles. Mean normalized multiplicity has also been studied in terms of created charged particles.