15,864 research outputs found
Evaluation of EREP techniques for geological mapping
The author has identified the following significant results. Skylab photographs may be successfully utilized for preparing a reconnaissance geological map in the areas where no maps or semi-detailed maps exist. Large coverage of area and regional perspective from Skylab photographs can help better coordination in regional mapping. It is possible to delineate major structural trends and other features like mega-lineaments, geofractures, and faults, which have evaded their detection by conventional methods. The photointerpretability is better in areas dominated by sedimentary rocks. Rock units of smaller extent and having poor geomorphic expressions are difficult to map. Demarcation of quaternary river alluvium can be made with better precision and ease with the Skylab photographs. Stereoscopic viewing greatly helps in interpretation of area structures. Skylab photographs are not good for preparing geological maps larger than 1:270,000 scale
Light-Front-Quantized QCD in Covariant Gauge
The light-front (LF) canonical quantization of quantum chromodynamics in
covariant gauge is discussed. The Dirac procedure is used to eliminate the
constraints in the gauge-fixed front form theory quantum action and to
construct the LF Hamiltonian formulation. The physical degrees of freedom
emerge naturally. The propagator of the dynamical part of the free
fermionic propagator in the LF quantized field theory is shown to be causal and
not to contain instantaneous terms. Since the relevant propagators in the
covariant gauge formulation are causal, rotational invariance---including the
Coulomb potential in the static limit---can be recovered, avoiding the
difficulties encountered in light-cone gauge. The Wick rotation may also be
performed allowing the conversion of momentum space integrals into Euclidean
space forms. Some explicit computations are done in quantum electrodynamics to
illustrate the equivalence of front form theory with the conventional covariant
formulation. LF quantization thus provides a consistent formulation of gauge
theory, despite the fact that the hyperplanes used to impose
boundary conditions constitute characteristic surfaces of a hyperbolic partial
differential equation.Comment: LaTex, 16 page
Hunting for asymptotia at LHC
We discuss whether the behaviour of some hadronic quantities, such as the
total cross-section, the ratio of the elastic to the total cross-section, are
presently exhibiting the asymptotic behaviour expected at very large energies.
We find phenomenological evidence that at LHC7 there is still space for further
evolution.Comment: 5 pages, 2 figures, talk given by G. Pancheri at International
Workshop on Diffraction in High-Energy Physics, DIFFRACTION 2012, Puerto del
Carmen, Canary Islands, Spain. To appear in AIP Conf. Pro
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