scholarly journals Dynamics of diffractive dissociation

2021 ◽  
Vol 81 (2) ◽  
Author(s):  
V. A. Khoze ◽  
A. D. Martin ◽  
M. G. Ryskin
Keyword(s):  
Cross Section ◽  
Momentum Fraction ◽  
Diffractive Dissociation ◽  
Particle Distributions ◽  
High Energies ◽  
Proton Dissociation ◽  
Dissociation Cross Section ◽  
Rapidity Gap ◽  
The Mean ◽  
Multiplicity Distributions

AbstractWe describe a QCD based model which incorporates the main properties of the inclusive particle distributions expected for diffractive processes, including the diffractive dissociation at high energies. We study, in turn, the total cross section, $$\sigma _\mathrm{tot}$$ σ tot , the differential elastic, $$d\sigma _\mathrm{el}/dt$$ d σ el / d t , cross section, the dependence of the single proton dissociation cross section, $$\xi d\sigma ^\mathrm{SD}/d\xi $$ ξ d σ SD / d ξ , on the momentum fraction, $$\xi =1-x_L$$ ξ = 1 - x L , lost by the leading proton, the multiplicity distributions in inelastic (non-diffractive) collisions and in the processes of dissociation. Besides this we calculate the mean transverse momenta of the ‘wee partons’ (secondaries) produced in the case of dissociation (that is in the processes with a large rapidity gap) and compare it with that in inelastic interactions.

scholarly journals Taming the Energy Rise of the Total Proton-Proton Cross-Section

Universe ◽  
2019 ◽  
Vol 5 (5) ◽  
pp. 106 ◽  
Author(s):  
Sergey Ostapchenko ◽  
Marcus Bleicher
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Strong Increase ◽  
Momentum Fraction ◽  
Proton Proton ◽  
High Energies ◽  
Model Predictions ◽  
Potential Impact ◽  
Very High

Steep rise of parton densities in the limit of small parton momentum fraction x poses a challenge for describing the observed energy-dependence of the total and inelastic proton-proton cross sections σ p p tot / inel : considering a realistic parton spatial distribution, one obtains a too-strong increase of σ p p tot / inel in the limit of very high energies. We discuss various mechanisms which allow one to tame such a rise, paying special attention to the role of parton-parton correlations. In addition, we investigate a potential impact on model predictions for σ p p tot, related to dynamical higher twist corrections to parton-production processes.

Inelastic diffractive-dissociation cross section inπ−pinteractions at 200 GeV/c

1978 ◽  
Vol 18 (11) ◽  
pp. 3933-3938 ◽  
Author(s):  
J. W. Lämsä ◽  
W. D. Walker ◽  
L. R. Fortney ◽  
A. T. Goshaw ◽  
J. S. Loos ◽  
...  
Keyword(s):  
Cross Section ◽  
Diffractive Dissociation ◽  
Dissociation Cross Section ◽  
200 Gev

A CONNECTION OF INELASTICITY WITH MULTIPLICITY DISTRIBUTION AT HIGH ENERGIES

1992 ◽  
Vol 07 (26) ◽  
pp. 2401-2406 ◽  
Author(s):  
ISAY GOLYAK
Keyword(s):  
Multiplicity Distribution ◽  
Secondary Particles ◽  
High Energies ◽  
The Mean ◽  
Multiplicity Distributions ◽  
Scaling Invariant

The widely known experimental value of the mean coefficient of the inelasticity <K>~0.5 is calculated by the investigation of a connection of the inelasticity with KNO scaling invariant multiplicity distributions of secondary particles.

scholarly journals Sources of Variability in the Response of Labeled Microspheres and B Cells during the Analysis by a Flow Cytometer

2021 ◽  
Vol 22 (15) ◽  
pp. 8256
Author(s):  
Adolfas K. Gaigalas ◽  
Yu-Zhong Zhang ◽  
Linhua Tian ◽  
Lili Wang
Keyword(s):  
B Cells ◽  
Laser Beam ◽  
Cross Section ◽  
Mean Fluorescence Intensity ◽  
Numerical Aperture ◽  
Flow Cytometer ◽  
Fluorescence Signal ◽  
Minor Importance ◽  
Reliable Measure ◽  
The Mean

A stochastic model of the flow cytometer measurement process was developed to assess the nature of the observed coefficient of variation (CV%) of the mean fluorescence intensity (MFI) from a population of labeled microspheres (beads). Several sources of variability were considered: the total number of labels on a bead, the path through the laser beam, the optical absorption cross-section, the quantum yield, the numerical aperture of the collection optics, and the photoelectron conversion efficiency of the photomultiplier (PMT) cathode. The variation in the number of labels on a bead had the largest effect on the CV% of the MFI of the bead population. The variation in the path of the bead through the laser beam was minimized using flat-top lasers. The variability in the average optical properties of the labels was of minor importance for beads with sufficiently large number of labels. The application of the bead results to the measured CV% of labeled B cells indicated that the measured CV% was a reliable measure of the variability of antibodies bound per cell. With some modifications, the model can be extended to multicolor flow cytometers and to the study of CV% from cells with low fluorescence signal.

scholarly journals INFLUENCE OF STATISTICAL FLUCTUATIONS ON K/π RATIOS IN RELATIVISTIC HEAVY ION COLLISIONS

2001 ◽  
Vol 16 (07) ◽  
pp. 1227-1235 ◽  
Author(s):  
C. B. YANG ◽  
X. CAI
Keyword(s):  
Negative Binomial ◽  
Heavy Ion ◽  
Relativistic Heavy Ion Collisions ◽  
Relative Variance ◽  
Ion Collisions ◽  
Statistical Fluctuations ◽  
Binomial Distributions ◽  
The Mean ◽  
Multiplicity Distributions ◽  
Statistical Background

The influence of pure statistical fluctuations on K/π ratio is investigated in an event-by-event way. Poisson and the modified negative binomial distributions are used as the multiplicity distributions since they both have statistical background. It is shown that the distributions of the ratio in these cases are Gaussian, and the mean and relative variance are given analytically.

scholarly journals Modeling plasma-based CO2conversion: crucial role of the dissociation cross section

2016 ◽  
Vol 25 (5) ◽  
pp. 055016 ◽  
Author(s):  
Annemie Bogaerts ◽  
Weizong Wang ◽  
Antonin Berthelot ◽  
Vasco Guerra
Keyword(s):  
Cross Section ◽  
Crucial Role ◽  
Dissociation Cross Section

PARTON RECOMBINATION IN CLASSICAL CASCADE

1990 ◽  
Vol 05 (28) ◽  
pp. 2377-2383 ◽  
Author(s):  
A. V. BATUNIN ◽  
O. P. YUSHCHENKO
Keyword(s):  
Explicit Form ◽  
Heavy Ion Collisions ◽  
Charged Particles ◽  
Heavy Ion ◽  
Considerable Decrease ◽  
High Energies ◽  
Ion Collisions ◽  
Parton Cascade ◽  
Energy Formula ◽  
The Mean

An equation for parton multiplicity in cascade with the recombination 1 → 2 ⊕ 2 → 1 is derived from a Kolmogorov-Chapman equation and solved. An evolution parameter τ of the cascade depends on the c.m. energy [Formula: see text]; an explicit form of the dependence is obtained from the condition that the mean multiplicity of charged particles in pp, [Formula: see text] collisions be reproduced. A considerable decrease in the mean multiplicity in heavy-ion collisions per pair of the colliding nucleons at high energies is predicted and compared to the parton cascade with no recombination.

Effects of Pin Shape and Array Orientation on Heat Transfer and Pressure Loss in Pin Fin Arrays

1984 ◽  
Vol 106 (1) ◽  
pp. 252-257 ◽  
Author(s):  
D. E. Metzger ◽  
C. S. Fan ◽  
S. W. Haley
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Pressure Loss ◽  
Flow Direction ◽  
Circular Cross Section ◽  
Cycle Performance ◽  
Mean Flow ◽  
Pin Fin ◽  
The Mean ◽  
Cooling Air

Modern high-performance gas turbine engines operate at high turbine inlet temperatures and require internal convection cooling of many of the components exposed to the hot gas flow. Cooling air is supplied from the engine compressor at a cost to cycle performance and a design goal is to provide necessary cooling with the minimum required cooling air flow. In conjunction with this objective, two families of pin fin array geometries which have potential for improving airfoil internal cooling performance were studied experimentally. One family utilizes pins of a circular cross section with various orientations of the array with respect to the mean flow direction. The second family utilizes pins with an oblong cross section with various pin orientations with respect to the mean flow direction. Both heat transfer and pressure loss characteristics are presented. The results indicate that the use of circular pins with array orientation between staggered and inline can in some cases increase heat transfer while decreasing pressure loss. The use of elongated pins increases heat transfer, but at a high cost of increased pressure loss. In conjunction with the present measurements, previously published results were reexamined in order to estimate the magnitude of heat transfer coefficients on the pin surfaces relative to those of the endwall surfaces. The estimate indicates that the pin surface coefficients are approximately double the endwall values.

A theory of incoherent scattering of radio waves by a plasma

1960 ◽  
Vol 259 (1296) ◽  
pp. 79-99 ◽  
Keyword(s):  
Cross Section ◽  
Thermal Fluctuations ◽  
Incoherent Scattering ◽  
Doppler Broadening ◽  
Radio Waves ◽  
Central Frequency ◽  
Resonance Effects ◽  
Doppler Shifts ◽  
The Mean ◽  
Free Plasma

A theory is developed which describes the scattering of radio waves by the random thermal fluctuations of electron density in a collision-free plasma. The frequency spectrum, as well as the amplitude, of the scattered radiation is calculated. Particular attention is paid to the part of the spectrum which corresponds to small Doppler shifts, this being the region of greatest significance in connexion with the phenomenon of incoherent scattering from the ionosphere. The calculations are based on a generalized version of Nyquist’s noise theorem, and they lead to the following conclusions: (1) The mean scattering cross-section for the ionosphere is equal to that which would exist if each of the electrons scattered independently with a cross-section of one-half the classical Thomson cross-section. (2) The mean Doppler broadening of the scattered signal corresponds roughly to the speed of the ions rather than to that of the electrons. (3) The spectral shape of this signal is not Gaussian. There is a mild maximum in the spectrum away from the central frequency, as can be seen in figure 1. (4) Plasma resonance effects contribute only negligibly to the scattering for frequencies currently of interest.

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