scholarly journals Energy dependence of hadron polarization ine+e−→hXat high energies

2017 ◽  
Vol 95 (3) ◽  
Author(s):  
Kai-bao Chen ◽  
Wei-hua Yang ◽  
Ya-jin Zhou ◽  
Zuo-tang Liang
Keyword(s):  
Energy Dependence ◽  
High Energies ◽  
Hadron Polarization

Fluctuations

2018 ◽  
Author(s):  
Richard Wigmans
Keyword(s):  
Energy Dependence ◽  
Energy Resolution ◽  
Practical Importance ◽  
Shower Particle ◽  
Formation Processes ◽  
Instrumental Effects ◽  
Important Type ◽  
High Energies ◽  
Different Types ◽  
Electromagnetic Component

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.

Energy dependence of hadron yields in pp and AA collisions

2015 ◽  
Vol 39 ◽  
pp. 1560109
Author(s):  
D. A. Artemenkov ◽  
G. I. Lykasov ◽  
A. I. Malakhov
Keyword(s):  
Energy Dependence ◽  
Hadron Production ◽  
Exponential Form ◽  
Suggested Approach ◽  
High Energies ◽  
Aa Collisions

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.

The dissociation of fast H 2 + ions by hydrogen

1960 ◽  
Vol 256 (1286) ◽  
pp. 416-426 ◽  
Keyword(s):  
Triplet State ◽  
Energy Dependence ◽  
Cross Sections ◽  
Large Fraction ◽  
Exchange Process ◽  
Hydrogen Gas ◽  
High Energies ◽  
Scintillation Crystals ◽  
The Cross ◽  
Simple Dissociation

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.

scholarly journals Energy Dependence of Delayed-Neutron Data

2019 ◽  
Vol 211 ◽  
pp. 01002
Author(s):  
Daniela Foligno ◽  
Pierre Leconte
Keyword(s):  
Energy Dependence ◽  
Direct Measurement ◽  
Radioactive Decay ◽  
Reactor Safety ◽  
Delayed Neutron ◽  
Neutron Data ◽  
High Energies ◽  
Experimental Values ◽  
Different Sources ◽  
Fission Yields

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.

scholarly journals Polarization control in spin-transparent hadron colliders by weak-field navigators involving lattice enhancement effect

2021 ◽  
Vol 81 (11) ◽  
Author(s):  
Yu. N. Filatov ◽  
A. M. Kondratenko ◽  
M. A. Kondratenko ◽  
Ya. S. Derbenev ◽  
V. S. Morozov ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Closed Orbit ◽  
Hadron Collider ◽  
Beam Polarization ◽  
Enhancement Effect ◽  
Interaction Point ◽  
Polarization Control ◽  
High Energies ◽  
Orbit Perturbation ◽  
Hadron Polarization

AbstractHadron polarization control schemes for Spin Transparent (ST) synchrotrons are analyzed. The spin dynamics and beam polarization in such synchrotrons are controlled by spin navigators (SN) which are special small insertions of weak magnetic fields. An SN stabilizes the beam polarization and allows for setting any desirable spin orientation at an interaction point in the operational regime, including a frequent spin flip. We present a general approach to design of SNs. We distinguish different types of SNs, namely, those not causing closed orbit perturbation as well as those producing local and global orbit distortions. In the second case, the concept of the spin response function in an ST synchrotron is applied and expanded to reveal the effect of the SN strength enhancement by magnetic lattice of the synchrotron. We provide conceptual schemes for SN designs using longitudinal and transverse magnetic fields allowing for polarization control at low as well as high energies. We also develop the ST concept for ultra-high energies. This development may enable and stimulate interest in polarized beam experiments in possible polarized collider projects such as Large Hadron Collider (LHC), Future Circular Collider (FCC) and Super Proton Proton Collider (SPPC).

scholarly journals Angular Momentum and Polarization in Hadron Collisions up to LHC Energies

2015 ◽  
Vol 37 ◽  
pp. 1560038
Author(s):  
Gary R. Goldstein ◽  
Simonetta Liuti
Keyword(s):  
Top Quark ◽  
Proton Accelerator ◽  
Spin Physics ◽  
Spin Asymmetries ◽  
Single Spin ◽  
High Energies ◽  
Single Spin Asymmetries ◽  
Charm Hadron ◽  
Gluon Distributions ◽  
Hadron Polarization

Longstanding puzzles in spin physics can be confronted at the high energies of the LHC. Heavy quarks will be produced with significant polarization, both as single spin asymmetries and through polarization correlations. Lower energy proton accelerator and leptoproduction data suggest various mechanisms within QCD for polarization phenomena that can be tested at higher energies. Observation of strange and charm hadron polarization reveals important aspects of QCD spin physics. Top quark polarization is predicted to be significant, and polarization correlations will reveal important aspects of the gluon distributions of the hadrons.

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