scholarly journals Where is the black disc limit?

1999 ◽  
Vol 11 (1) ◽  
pp. 145-151 ◽  
Author(s):  
P. Desgrolard ◽  
L. Jenkovszky ◽  
B. Struminsky
Keyword(s):  
Black Disc ◽  
Black Disc Limit

scholarly journals TACHYON DYNAMICS OF THE BLACK DISC LIMIT IN THE HARD SMALL x PROCESSES IN QCD

2006 ◽  
Vol 21 (07) ◽  
pp. 549-558 ◽  
Author(s):  
B. BLOK ◽  
L. FRANKFURT
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
High Energy ◽  
Black Disk ◽  
Black Disc ◽  
Energy Behavior ◽  
Small X ◽  
The Cross ◽  
The Impact ◽  
Black Disc Limit

We investigate the effective field theory (EFT) which gives the approximate description of the scattering of two hard small dipoles in the small x processes in QCD near the black disc limit (BDL). We argue that the perturbative QCD approaches predict the existence of tachyon and visualize it in the approximation where α′P=0. We demonstrate that the high energy behavior of the cross-section depends strongly on the diffusion law in the impact parameter plane. On the other hand, almost threshold behavior of the cross section of the hard processes and multiplicities, i.e. fast increase of cross sections (color inflation), melting of ladders into color network and softening of the longitudinal distributions of hadrons are qualitatively insensitive to the value of diffusion in the impact parameter space. We evaluate α′P near the black disk limit and find significant α′P as the consequence of the probability conservation.

Where is the black disc limit?

1999 ◽  
Vol 11 (1) ◽  
pp. 145 ◽  
Author(s):  
P. Desgrolard ◽  
L. Jenkovszky ◽  
B. Struminsky
Keyword(s):  
Black Disc ◽  
Black Disc Limit

scholarly journals Tachyon dynamics of the black disc limit in the hard small x processes in QCD

2007 ◽  
Vol 782 (1-4) ◽  
pp. 335-345
Author(s):  
B. Blok ◽  
L. Frankfurt
Keyword(s):  
Black Disc ◽  
Small X ◽  
Black Disc Limit

The black disc jockey as a cultural hero

1986 ◽  
Vol 10 (3) ◽  
pp. 79-90 ◽  
Author(s):  
Gilbert A. Williams
Keyword(s):  
Black Disc ◽  
Disc Jockey ◽  
Cultural Hero

Jack Cooper: The first black disc jockey

1992 ◽  
Vol 16 (2) ◽  
pp. 43-49
Author(s):  
Arnold Passman
Keyword(s):  
Black Disc ◽  
Disc Jockey

scholarly journals Highest energy proton–nucleus cross-sections

2018 ◽  
Vol 33 (40) ◽  
pp. 1850242 ◽  
Author(s):  
L. Stodolsky
Keyword(s):  
Cosmic Rays ◽  
Cross Sections ◽  
High Energy ◽  
High Energy Proton ◽  
Proton Proton ◽  
Energy Proton ◽  
Black Disc ◽  
Simple Generalization ◽  
Very High Energy ◽  
Very High

The description of very high energy proton–proton cross-sections in terms of a “black disc” with an “edge” allows a simple generalization to highest energy proton–nucleus cross-sections. This results in a leading ln2W term and a ln W term whose coefficient depends linearly on the radius of the nucleus (W the c.m. energy). The necessary parameters are determined from the fits to p–p data. Since the coefficient of the ln W term is rather large, it is doubtful that the regime of ln2W dominance can be reached with available energies in accelerators or cosmic rays. However, the ln W term can be relevant for highest energy cosmic rays in the atmosphere, where a large increase for the cross-section on nitrogen is expected. Tests of the theory should be possible by studying the coefficient of ln W at p-nucleus colliders.

scholarly journals Black disc disease: a commentary

2002 ◽  
Vol 13 (2) ◽  
pp. 1-4 ◽  
Author(s):  
Setti S. Rengachary ◽  
Raju S. V. Balabhadra
Keyword(s):  
Magnetic Resonance Imaging ◽  
Radicular Pain ◽  
Clinical Syndrome ◽  
Allograft Bone ◽  
Disease Entity ◽  
Resonance Imaging ◽  
Disc Disease ◽  
Black Disc ◽  
Surgical Options ◽  
Anterior Column Support

Internal disc disruption associated with axial back pain but not radicular pain is a disease entity that was recognized about two decades ago as a disorder that could potentially be treated by spinal fusion. In this article the authors describe the clinical syndrome, magnetic resonance imaging and discography findings of pathophysiological pain generation, and the available surgical options. Based on the current understanding of this disease entity, the optimum surgical procedure entails radical discectomy, anterior column support, adequate amounts of auto- or allograft bone, bone extenders and enhancers, and rigid stabilization of the motion segment.

Factors affecting the water clarity of ponds on the McMurdo Ice Shelf, Antarctica

1995 ◽  
Vol 7 (2) ◽  
pp. 145-148 ◽  
Author(s):  
R.D. Pridmore ◽  
W.N. Vant ◽  
V.J. Cummings
Keyword(s):  
Water Clarity ◽  
Ice Shelf ◽  
Organic Detritus ◽  
Factors Affecting ◽  
Suspended Particulates ◽  
Beam Attenuation ◽  
Black Disc ◽  
Yellow Substance ◽  
Solids Concentration ◽  
Beam Attenuation Coefficient

The clarity of 39 meltwater ponds on the McMurdo Ice Shelf was determined as the horizontal viewing range of a black disc. Visual ranges varied widely from pond to pond from 0.14–5 m; so did the concentrations of optically-active constituents, including the suspended particulates, phytoplankton (10-fold variation) and inorganic suspensoids (> 100-fold), and dissolved yellow substance (10-fold). In six of the ponds the ratio of beam attenuation coefficient to total suspended solids concentration was low (< 0.6 m2 g−1) compared to that in the others (0.7–2.0 m2 g−1, suggesting that generally larger particles were present suspended in the water in these ponds. In both groups, relationships between beam attenuation and constituent concentrations indicated that much of the attenuation was due to inorganic suspensoids. Organic detritus also appeared to be important in many ponds, while phytoplankton and dissolved yellow substance were generally less important. Even though the clarity of many of the ponds was poor, their relative shallowness meant levels of underwater light were probably generally adequate for benthic plant growth.

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