Multichannel Approach to High-Energy Peripheral Collisions

1965 ◽  
Vol 139 (1B) ◽  
pp. B179-B183 ◽  
Author(s):  
D. B. Lichtenberg ◽  
P. K. Williams
Keyword(s):  
High Energy ◽  
Peripheral Collisions

Recent experiments with counters at the C.E.R.N. proton synchrotron

1964 ◽  
Vol 278 (1374) ◽  
pp. 340-350
Keyword(s):  
Elementary Particle ◽  
High Energy Physics ◽  
Bubble Chamber ◽  
Regge Pole ◽  
High Energy ◽  
Point Of View ◽  
Proton Synchrotron ◽  
Peripheral Collisions ◽  
Break Up ◽  
Compound Particle

I feel I should begin by pointing out that in at least two respects I am not qualified to give this talk. The first is that our machine at Liverpool is of course a 400 MeV machine, which only counts as a low-energy one these days, and I have not worked at C. E. R. N. where the real high-energy physics in Europe is now being done; I can only speak about it at second hand. I have, however, been making rather frequent visits to C. E. R. N. recently, thanks to an invitation from Professor Weisskopf, so that I can give some description of the counter experiments on the proton synchrotron there. The description is necessarily from a spectator’s point of view, and to that extent, superficial. The second lack of qualification comes from the fact that Professor Weisskopf has explained all the easy part about the significance of the most interesting counter experiments, so that I have to try and go a little further. Now, that necessarily involves me in the extremely sophisticated and conjectural ideas of the Regge pole analysis, which are not easy to explain to non-specialists. I shall try to convey the spirit if not the substance of that analysis. However, I should like to begin with a description of a different experiment, bearing on the elementary particle spectroscopy to which Professor Weisskopf drew your attention this morning. The main details of elementary-particle spectroscopy have of course come to use from bubble-chamber experiments, and, on the whole, the counter programme has not made a great contribution to it. One experiment, however, that is unusually clear is the counter experiment of Caldwell et al . on the production of associated bosons from peripheral collisions. Figure 37 shows the sort of process that is sought in this experiment. A highenergy pion beam is directed at a nucleon and glancing collisions are sought; in other words, collisions that take place at a long range and are probably associated with the exchange of one particle. Of course, the range of the interaction is longer when the mass of the exchange particles is small, so a single pion is most likely to be exchanged. The nucleon emits this pion and may itself break up into a number of particles, which the experiment does not investigate any further. At the other vertex the exchange particle joins the pion and, hopefully, makes a compound particle which later breaks up into associated bosons, either two pions or two kaons. If the particle exchanged is a pion, of course, this short-lived compound particle has strangeness zero, and therefore it can only break up into two pions or two kaons, but not into a kaon and a pion.

Coupled-Channel Schrödinger-Equation Model for High-Energy Peripheral Collisions

1966 ◽  
Vol 143 (4) ◽  
pp. 1375-1388 ◽  
Author(s):  
John G. Wills ◽  
David Ellis ◽  
D. B. Lichtenberg
Keyword(s):  
Schrödinger Equation ◽  
Schrodinger Equation ◽  
High Energy ◽  
Equation Model ◽  
Peripheral Collisions ◽  
Coupled Channel

scholarly journals Interaction of 160-GeV muon with emulsion nuclei

2018 ◽  
Vol 27 (01) ◽  
pp. 1850007 ◽  
Author(s):  
S. M. Othman ◽  
M. T. Ghoneim ◽  
M. T. Hussein ◽  
H. El-Samman ◽  
A. Hussein
Keyword(s):  
Angular Distribution ◽  
Electric Field ◽  
Cross Section ◽  
High Energy ◽  
Energy Spectra ◽  
Giant Resonances ◽  
Peripheral Collisions ◽  
Impact Parameters

In this work we present some results of the interaction of high-energy muons with emulsion nuclei. The interaction results in emission of a number of fragments as a consequence of electromagnetic dissociation of the excited target nuclei. This excitation is attributed to absorption of photons by the target nuclei due to the intense electric field of the very fast incident muon particles. The interactions take place at impact parameters that allow ultra-peripheral collisions to take place, leading to giant resonances and hence multifragmentation of emulsion targets. Charge identification, range, energy spectra, angular distribution and topological cross-section of the produced fragments are measured and evaluated.

Color fluctuations in high energy hadron- and photon-nucleus collisions

2016 ◽  
Vol 31 (28n29) ◽  
pp. 1645015
Author(s):  
Leonid Frankfurt ◽  
Mark Strikman
Keyword(s):  
Bound States ◽  
High Energy ◽  
Vector Mesons ◽  
Significant Modification ◽  
Future Studies ◽  
Slowing Down ◽  
Peripheral Collisions ◽  
Energy Hadron ◽  
Electron Photon ◽  
New Phenomena

We explain that coherence of high energy QED and QCD processes implies existence of new kind of phenomena which are beyond a framework based on Regge poles (cuts). New phenomena emerge as the consequence of compositeness of the bound states and the Lorentz slowing down of interaction. We focus on the color fluctuations phenomena predicted earlier for [Formula: see text] collisions within QCD and recent evidence for this phenomenon from [Formula: see text] LHC run, significant modification of nuclear shadowing phenomenon in the diffractive photoproduction of vector mesons observed recently in the ultra peripheral collisions at LHC. We outlined briefly general properties of color fluctuations phenomena and perspectives of future studies of this phenomenon in electron (photon) collisions with nuclei.

scholarly journals Fading out of J/ψ color transparency in high energy heavy ion peripheral collisions

2002 ◽  
Vol 540 (3-4) ◽  
pp. 220-226 ◽  
Author(s):  
L. Frankfurt ◽  
M. Strikman ◽  
M. Zhalov
Keyword(s):  
Heavy Ion ◽  
High Energy ◽  
Color Transparency ◽  
Peripheral Collisions

scholarly journals Hydrodynamical response of plane correlation in Pb + Pb collisions at s NN = 2.76TeV

2019 ◽  
Vol 28 (10) ◽  
pp. 1950092
Author(s):  
Jing Yang ◽  
Yong Zhang ◽  
Wei-Ning Zhang
Keyword(s):  
Heavy Ion ◽  
High Energy ◽  
Glauber Model ◽  
Order Effects ◽  
Single Shot ◽  
Anisotropic Flow ◽  
Event Plane ◽  
Ion Collisions ◽  
Peripheral Collisions ◽  
Participant Plane

In high energy heavy-ion collisions, the final anisotropic flow coefficients and their corresponding event–plane correlations are considered as the medium evolutional response to the initial geometrical eccentricities and their corresponding participant–plane correlations. We formulate a systematic theoretical analysis to study the hydrodynamical responses concerning higher-order effects in [Formula: see text] collisions at [Formula: see text][Formula: see text]TeV by using Monte Carlo (MC) Glauber model. To further understand the transformations of the initial participant–plane correlation, we construct a new set of events which randomize the directions of the initial participant–planes of the original events. Our results indicate that the final strong event–plane correlations are mainly transformed from the large initial eccentricities, rather than the strong participant–plane correlations. However, the large flow coefficients and the discrepancies between the flow coefficients calculated by the single-shot and event-by-event simulations in peripheral collisions are relevant to those strong initial participant–plane correlations.

The E-ring: interactions with plasma and implications for its evolution

1984 ◽  
Vol 75 ◽  
pp. 599-602
Author(s):  
T.V. Johnson ◽  
G.E. Morfill ◽  
E. Grun
Keyword(s):  
Time Scale ◽  
Particle Density ◽  
High Energy ◽  
Particle Removal ◽  
Density Region ◽  
Drag Forces ◽  
Orbit Evolution ◽  
History Of ◽  
Ring Particle ◽  
Ring Material

A number of lines of evidence suggest that the particles making up the E-ring are small, on the order of a few microns or less in size (Terrile and Tokunaga, 1980, BAAS; Pang et al., 1982 Saturn meeting; Tucson, AZ). This suggests that a variety of electromagnetic and plasma affects may be important in considering the history of such particles. We have shown (Morfill et al., 1982, J. Geophys. Res., in press) that plasma drags forces from the corotating plasma will rapidly evolve E-ring particle orbits to increasing distance from Saturn until a point is reached where radiation drag forces acting to decrease orbital radius balance this outward acceleration. This occurs at approximately Rhea's orbit, although the exact value is subject to many uncertainties. The time scale for plasma drag to move particles from Enceladus' orbit to the outer E-ring is ~104yr. A variety of effects also act to remove particles, primarily sputtering by both high energy charged particles (Cheng et al., 1982, J. Geophys. Res., in press) and corotating plasma (Morfill et al., 1982). The time scale for sputtering away one micron particles is also short, 102 - 10 yrs. Thus the detailed particle density profile in the E-ring is set by a competition between orbit evolution and particle removal. The high density region near Enceladus' orbit may result from the sputtering yeild of corotating ions being less than unity at this radius (e.g. Eviatar et al., 1982, Saturn meeting). In any case, an active source of E-ring material is required if the feature is not very ephemeral - Enceladus itself, with its geologically recent surface, appears still to be the best candidate for the ultimate source of E-ring material.

Analysis of electron-diffraction intensity profiles using a photodiode-array detection system

1983 ◽  
Vol 41 ◽  
pp. 322-323
Author(s):  
J. B. Warren
Keyword(s):  
Electron Diffraction ◽  
Diffraction Pattern ◽  
Detection System ◽  
High Energy ◽  
Photographic Emulsion ◽  
Diffraction Intensity ◽  
Silicon Photodiode ◽  
Photodiode Array Detection ◽  
Analog To Digital ◽  
Photodiode Array

Electron diffraction intensity profiles have been used extensively in studies of polycrystalline and amorphous thin films. In previous work, diffraction intensity profiles were quantitized either by mechanically scanning the photographic emulsion with a densitometer or by using deflection coils to scan the diffraction pattern over a stationary detector. Such methods tend to be slow, and the intensities must still be converted from analog to digital form for quantitative analysis. The Instrumentation Division at Brookhaven has designed and constructed a electron diffractometer, based on a silicon photodiode array, that overcomes these disadvantages. The instrument is compact (Fig. 1), can be used with any unmodified electron microscope, and acquires the data in a form immediately accessible by microcomputer.Major components include a RETICON 1024 element photodiode array for the de tector, an Analog Devices MAS-1202 analog digital converter and a Digital Equipment LSI 11/2 microcomputer. The photodiode array cannot detect high energy electrons without damage so an f/1.4 lens is used to focus the phosphor screen image of the diffraction pattern on to the photodiode array.

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