113 research outputs found
Ariel - Volume 3 Number 5
Editors
Richard J. Bonanno
Robin A. Edwards
Associate Editors
Steven Ager
Tom Williams
Lay-out Editor
Eugenia Miller
Contributing Editors
Paul Bialas
Robert Breckenridge
Lynne Porter
David Jacoby
Terry Burt
Mark Pearlman
Michael Leo
Mike LeWitt
Editors Emeritus
Delvyn C. Case., Jr.
Paul M. Fernhof
Ariel - Volume 3 Number 2
Editors
Richard J. Bonanno
Robin A. Edwards
Associate Editors
Steven Ager
Stephen Flynn
Tom Williams
Lay-out Editor
Eugenia Miller
Contributing Editors
Paul Bialas
Milton Packer
Robert Breckenridge
Lynne Porter
Mark Pearlman
Terry Burt
Mike Leo
Editors Emeritus
Delvyn C. Case, Jr.
Paul M. Fernhof
Ariel - Volume 3 Number 8
Editors
Richard J. Bonanno
Robin A. Edwards
Associate Editors
Steven Ager
Tom Williams
Lay-out Editor
Eugenia Miller
Contributing Editors
Paul Bialas
Robert Breckenridge
David Jacoby
Mike LeWitt
Terry Burt
Michael Leo
Editors Emeritus
Delvyn C. Case, Jr.
Paul M. Fernhof
Signals of the quark-gluon plasma in nucleus-nucleus collisions
This talk is a brief overview of the present status of our understanding of
nucleus-nucleus collisions at high energy and the search for signals of the
quark-gluon plasma.Comment: flatex qm99.tex, 2 files XIV International Conference on
`Ultra-Relativistic Nucleon-Nucleon Collisions' Torino, Italie 1999-05-10
1999-05-15 May 10-15, 1999 [SPhT-T99/103
Status of the Micro Vertex Detector of the Compressed Baryonic Matter Experiment
The CBM experiment will investigate heavy-ion collisions at beam energies from 8 to 45 AGeV
at the future accelerator facility FAIR. The goal of the experiment is to study the QCD phase
diagram in the vincinity of the QCD critical point. To do so, CBM aims at measuring rare probes
among them open charm. In order to identify those rare and short lived particles despite the
rich combinatorial background generated in heavy ion collisions, a micro vertex detector (MVD)
providing an unprecedented combination of high rate capability and radiation hardness, very light
material budget and excellent granularity is required. In this work, we will discuss the concept of
this detector and summarize the status of the R&D
High Energy Physics in the Atmosphere: Phenomenology of Cosmic Ray Air Showers
The properties of cosmic rays with energies above 10**6 GeV have to be
deduced from the spacetime structure and particle content of the air showers
which they initiate. In this review we summarize the phenomenology of these
giant air showers. We describe the hadronic interaction models used to
extrapolate results from collider data to ultra high energies, and discuss the
prospects for insights into forward physics at the LHC. We also describe the
main electromagnetic processes that govern the longitudinal shower evolution,
as well as the lateral spread of particles. Armed with these two principal
shower ingredients and motivation from the underlying physics, we provide an
overview of some of the different methods proposed to distinguish primary
species. The properties of neutrino interactions and the potential of
forthcoming experiments to isolate deeply penetrating showers from baryonic
cascades are also discussed. We finally venture into a terra incognita endowed
with TeV-scale gravity and explore anomalous neutrino-induced showers.Comment: Typo in caption of Fig. 8 corrected, references adde
Geological fate of seafloor massive sulphides at the TAG hydrothermal field (Mid-Atlantic Ridge)
Highlights
• Generic geological model of hydrothermally extinct seafloor massive sulphide.
• Sub-surface characterisation by combined drilling and geophysics.
• New resource estimate for slow-spreading mid-ocean ridges.
• Holistic approach to seafloor mineral deposits assessment.
Abstract
Deep-sea mineral deposits potentially represent vast metal resources that could make a major contribution to future global raw material supply. Increasing demand for these metals, many of which are required to enable a low-carbon and high-technology society and to relieve pressure on land-based resources, may result in deep sea mining within the next decade. Seafloor massive sulphide (SMS) deposits, containing abundant copper, zinc, gold and silver, have been the subject of recent and ongoing commercial interest. Although many seafloor hydrothermally systems have been studied, inactive SMS deposits are likely to more accessible to future mining and far more abundant, but are often obscured by pelagic sediment and hence difficult to locate. Furthermore, SMS deposits are three dimensional. Yet, to date, very few have been explored or sampled below the seafloor. Here, we describe the most comprehensive study to date of hydrothermally extinct seafloor massive sulphide deposits formed at a slow spreading ridge. Our approach involved two research cruises in the summer of 2016 to the TAG hydrothermal field at 26°N on the Mid-Atlantic Ridge. These expeditions mapped a number of hydrothermally extinct SMS deposits using an autonomous underwater vehicle and remotely operated vehicle, acquired a combination of geophysical data including sub-seafloor seismic reflection and refraction data from 25 ocean bottom instruments, and recovered core using a sub-seafloor drilling rig. Together, these results that have allowed us to construct a new generic model for extinct seafloor massive sulphide deposits that indicate the presence of up to five times more massive sulphide at and below the seafloor than was previously thought
Contrasting styles of (U)HP rock exhumation along the Cenozoic Adria-Europe plate boundary (Western Alps, Calabria, Corsica)
Since the first discovery of ultrahigh pressure (UHP) rocks 30 years ago in the Western Alps, the mechanisms for exhumation of (U)HP terranes worldwide are still debated. In the western Mediterranean, the presently accepted model of synconvergent exhumation (e.g., the channel-flow model) is in conflict with parts of the geologic record. We synthesize regional geologic data and present alternative exhumation mechanisms that consider the role of divergence within subduction zones. These mechanisms, i.e., (i) the motion of the upper plate away from the trench and (ii) the rollback of the lower plate, are discussed in detail with particular reference to the Cenozoic Adria-Europe plate boundary, and along three different transects (Western Alps, Calabria-Sardinia, and Corsica-Northern Apennines). In the Western Alps, (U)HP rocks were exhumed from the greatest depth at the rear of the accretionary wedge during motion of the upper plate away from the trench. Exhumation was extremely fast, and associated with very low geothermal gradients. In Calabria, HP rocks were exhumed from shallower depths and at lower rates during rollback of the Adriatic plate, with repeated exhumation pulses progressively younging toward the foreland. Both mechanisms were active to create boundary divergence along the Corsica-Northern Apennines transect, where European southeastward subduction was progressively replaced along strike by Adriatic northwestward subduction. The tectonic scenario depicted for the Western Alps trench during Eocene exhumation of (U)HP rocks correlates well with present-day eastern Papua New Guinea, which is presented as a modern analog of the Paleogene Adria-Europe plate boundary
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