Trends in the energy dependence of strong interaction characteristics at ultra-high energies

1973 ◽  
Vol 6 (12) ◽  
pp. 1990-1990
Author(s):  
R H Vatcha ◽  
B V Sreekantan
Author(s):  
Richard Wigmans

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.


2015 ◽  
Vol 39 ◽  
pp. 1560109
Author(s):  
D. A. Artemenkov ◽  
G. I. Lykasov ◽  
A. I. Malakhov

To describe the data on hadron production at high energies in the midarapidity region and not large transverse momenta [Formula: see text], we modify the simple exponential form of the [Formula: see text]-spectrum. The hadron [Formula: see text]-spectrum is presented in two parts due to the contributions of quarks and gluons, each of them has different energy dependence. The suggested approach alows us to describe rather satisfactorily the inclusive spectra of hadrons produced in [Formula: see text] collisions at energies from the AGS up to LHC.


H 2 + ions of energy 100 to 800 keV have been passed through hydrogen gas and the cross-sections for the following four processes determined : (1) H 2 + → H + + H O , (2) H 2 + → H + + H + , (3) H 2 + → H O + H O , (4) H 2 + → H 2 O . A magnetic field was used to separate the fast dissociation products of different e / m , and CsI(Tl) scintillation crystals were used as detectors. Double-height pulses resulted when two particles of the same e / m , simultaneously entered one of the crystals and were clearly resolved from single pulses. Processes (3) and (4) were separated by moving a fine slit across the neutral-particle counter which thus counted only H 2 O particles as double pulses. The partial cross-sections for processes (1) and (2) show an E -1 dependence at high energies. The energy dependence is less marked below 300 keV, where the Born approximation might be expected to be invalid. The partial cross-sections for processes (3) and (4) show the strong energy dependence characteristic of an electron-exchange process. The angular distribution for process (3) is consistent with the reaction proceeding via the 1 3 Ʃ u repulsive triplet state. The large fraction of the capture reactions proceeding this way (70%), is reasonable considering the high probability of formation in the triplet state. The large values of the cross-sections for processes other than simple dissociation account, in part, for the considerable discrepancies between the results of other workers.


2019 ◽  
Vol 211 ◽  
pp. 01002
Author(s):  
Daniela Foligno ◽  
Pierre Leconte

Delayed neutron data is essential in inherent reactor safety and in reactor control. The different sources and results of delayed neutron data in international databases will be discussed. In addition to direct measurement, these data can be obtained by calculations based on fission yields (FY) and radioactive decay data (RDD). Unfortunately, FY are only given at three energies in the European library JEFF. This works proposes to use GEF-FY energy dependence to extrapolate JEFF-FY at other energies. The preliminary results highlight that GEF energy dependence is not always suitable to reproduce experimental values and that more measurements are needed at high energies.


2017 ◽  
Vol 95 (3) ◽  
Author(s):  
Kai-bao Chen ◽  
Wei-hua Yang ◽  
Ya-jin Zhou ◽  
Zuo-tang Liang

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