10 research outputs found
Conference Web Site Redesign
Sustainable Resources was a non-profit organization based out of Boulder, CO that, at the time of this project hosted yearly conferences to help find solutions to world poverty. Although, the previous web site had a professional appearance, it was not meeting their needs with regards to usability, extensibility, and maintainability, as they had been forced to rely heavily on a transient volunteer IT labor base. The aim of this project was to address their functional and maintenance problems. The application\u27s front-end was built in adherence to the Model -view-Controller (MVC) design pattern and implemented using the Jakarta Struts framework and consisted of, a JSP interface. Hibernate was used as the database persistence layer and the entire data model was completely replaced, as certain data fields were being duplicated in the former system. While giving Sustainable Resources the same functionality they had previously enjoyed, the new application enabled the site\u27s administrators to effectively maintain parts of the application without IT support and supplied them with the necessary documentation to assist future developers with upgrades
Critical Behavior at the Chiral Phase Transition
Quantum chromodynamics with two zero mass flavors is expected to exhibit a
phase transition with O(4) critical behavior. Fixing the universality class is
important for phenomenology and for facilitating the extrapolation of
simulation data to physical quark mass values. At Lattice '96 the Tsukuba and
Bielefeld groups reported results from new simulations with dynamical staggered
quarks at , which suggested a departure from the expected critical
behavior. We report observations of similar deviations and discuss efforts in
progress to understand this phenomenon.Comment: 3 pp, LaTeX with 6 encapsulated Postscript figures. Lattice '97
proceeding
Thermodynamics for two flavor QCD
We conclude our analysis of the N_t=6 equation of state for two flavor QCD,
first described at last year's conference. We have obtained new runs at
am_q=0.025 and improved runs at am_q=0.0125. The results are extrapolated to
m_q=0, and we extract the speed of sound as well. We also present evidence for
a restoration of the SU(2) X SU(2) chiral symmetry just above the crossover,
but not of the axial U(1) chiral symmetry.Comment: Poster presented at LATTICE96(finite temperature). 4 pages, LaTeX
plus 5 encapsulated Postscript figure
The equation of state for two flavor QCD at N_t=6
We calculate the two flavor equation of state for QCD on lattices with
lattice spacing a=(6T)^{-1} and find that cutoff effects are substantially
reduced compared to an earlier study using a=(4T)^{-1}. However, it is likely
that significant cutoff effects remain. We fit the lattice data to expected
forms of the free energy density for a second order phase transition at
zero-quark-mass, which allows us to extrapolate the equation of state to m_q=0
and to extract the speed of sound. We find that the equation of state depends
weakly on the quark mass for small quark mass.Comment: 24 pages, latex, 11 postscipt figure
Two-Flavor Staggered Fermion Thermodynamics at N_t = 12
We present results of an ongoing study of the nature of the high temperature
crossover in QCD with two light fermion flavors. These results are obtained
with the conventional staggered fermion action at the smallest lattice spacing
to date---approximately 0.1 fm. Of particular interest are a study of the
temperature of the crossover a determination of the induced baryon charge and
baryon susceptibility, the scalar susceptibility, and the chiral order
parameter, used to test models of critical behavior associated with chiral
symmetry restoration. From our new data and published results for N_t = 4, 6,
and 8, we determine the QCD magnetic equation of state from the chiral order
parameter using O(4) and mean field critical exponents and compare it with the
corresponding equation of state obtained from an O(4) spin model and mean field
theory. We also present a scaling analysis of the Polyakov loop, suggesting a
temperature dependent ``constituent quark free energy.''Comment: LaTeX 25 pages, 15 Postscript figure
Long Range Plan: Dense matter theory for heavy-ion collisions and neutron stars
Since the release of the 2015 Long Range Plan in Nuclear Physics, major
events have occurred that reshaped our understanding of quantum chromodynamics
(QCD) and nuclear matter at large densities, in and out of equilibrium. The US
nuclear community has an opportunity to capitalize on advances in astrophysical
observations and nuclear experiments and engage in an interdisciplinary effort
in the theory of dense baryonic matter that connects low- and high-energy
nuclear physics, astrophysics, gravitational waves physics, and data scienceComment: 70 pages, 3 figures, White Paper for the Long Range Plan for Nuclear
Scienc