58 research outputs found
Chiral bosonization and local Lorentz-invariant actions for chiral bosons
Journal ArticleWe formulate a geometrical theory of self-dual scalar fields in two dimensions with a local Lorentz-invariant action. Path-integral quantization is used to derive chiral bosonization by demonstrating equivalence of correlation functions of currents and energy-momentum tensors in our theory with those for Weyl fermions
Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry
This SciDAC project enabled a multidisciplinary research consortium to develop a high fidelity direct numerical simulation (DNS) software package for the simulation of turbulent reactive flows. Within this collaboration, the authors, based at CMU's Pittsburgh Supercomputing Center (PSC), focused on extensive new developments in Sandia National Laboratories' "S3D" software to address more realistic combustion features and geometries while exploiting Terascale computational possibilities. This work significantly advances the state-of-the-art of DNS of turbulent reacting flows
Spectral Density Study of the SU(3) Deconfining Phase Transition
We present spectral density reweighting techniques adapted to the analysis of
a time series of data with a continuous range of allowed values. In a first
application we analyze action and Polyakov line data from a Monte Carlo
simulation on lattices for the SU(3) deconfining phase
transition. We calculate partition function zeros, as well as maxima of the
specific heat and of the order parameter susceptibility. Details and warnings
are given concerning i) autocorrelations in computer time and ii) a reliable
extraction of partition function zeros. The finite size scaling analysis of
these data leads to precise results for the critical couplings , for
the critical exponent and for the latent heat . In both
cases ( and 4), the first order nature of the transition is
substantiated
Eikonal representation in the momentum-transfer space
By means of empirical fits to the differential cross section data on pp and
p(bar)p elastic scattering, above 10 GeV (center-of-mass energy), we determine
the eikonal in the momentum - transfer space (q^2- space). We make use of a
numerical method and a novel semi-analytical method, through which the
uncertainties from the fit parameters can be propagated up to the eikonal in
the - space. A systematic study of the effect of the experimental
information at large values of the momentum transfer is developed and discussed
in detail. We present statistical evidence that the imaginary part of the
eikonal changes sign in the q^2- space and that the position of the zero
decreases as the energy increases; after the position of the zero, the eikonal
presents a minimum and then goes to zero through negative values. We discuss
the applicability of our results in the phenomenological context, outlining
some connections with nonperturbative QCD. A short review and a critical
discussion on the main results concerning "model-independent" analyses are also
presented.Comment: 18 pages, 17 figures, 4 tables, svjour.cls. Revised discussion on the
proton's electromagnetic form factor and references added. To appear in Eur.
Phys. J.
Evidence for eikonal zeros in the momentum transfer space
We present the results of fitting elastic differential cross section
data at 23.5 62.5 GeV with a novel analytic
parametrization for the scattering amplitude. Making use of a fitting method,
the errors from the free parameters are propagated to the imaginary part of the
eikonal in the momentum transfer space. A novel systematic study of the effects
coming from data at large momentum transfer is also performed. We find
statistical evidence for the existence of eikonal zeros in the interval of
momentum transfer 5-9 .Comment: Text with 9 pages in Revtex (preprint form), 8 figures in PostScript.
Replaced with small changes. Final version to be published in Physical Review
GPDs of the nucleons and elastic scattering at high energies
Taking into account the electromagnetic and gravitational form factors,
calculated from a new set of -dependent GPDs, a new model is built. The
real part of the hadronic amplitude is determined only through complex . In
the framework of this model the quantitative description of all existing
experimental data at GeV, including the
Coulomb range and large momentum transfers ($0.0008 \leq |t| \leq 9.75 \
^237$ TeV is made.Comment: 14 pages, 21 figures, minor corrections (slightly brush English and
removed two misprint in numbering
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