609 research outputs found
Shift in critical temperature for random spatial permutations with cycle weights
We examine a phase transition in a model of random spatial permutations which
originates in a study of the interacting Bose gas. Permutations are weighted
according to point positions; the low-temperature onset of the appearance of
arbitrarily long cycles is connected to the phase transition of Bose-Einstein
condensates. In our simplified model, point positions are held fixed on the
fully occupied cubic lattice and interactions are expressed as Ewens-type
weights on cycle lengths of permutations. The critical temperature of the
transition to long cycles depends on an interaction-strength parameter
. For weak interactions, the shift in critical temperature is expected
to be linear in with constant of linearity . Using Markov chain
Monte Carlo methods and finite-size scaling, we find .
This finding matches a similar analytical result of Ueltschi and Betz. We also
examine the mean longest cycle length as a fraction of the number of sites in
long cycles, recovering an earlier result of Shepp and Lloyd for non-spatial
permutations.Comment: v2 incorporated reviewer comments. v3 removed two extraneous figures
which appeared at the end of the PDF
Investigation of High-Spin, Particle-Hole Excitation in 208-Pb with Inelastic Proton Scattering at 200 MeV
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
A Test of Coplanarity and Far-Side Dominance in Intermediate Energy (d,p) and (p,d) Reactions
This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440
The Liverpool Statement 2005: Priorities for the European Union/United States Spiral Computed Tomography Collaborative Group
The Liverpool Statement 2005 was developed at the Fourth International Lung Cancer Molecular Biomarkers Workshop in Liverpool (October 27-29, 2005) and focused on the priorities for the European Union/United States (EU-US) Spiral Computed Tomography (CT) Collaborative Group. The application of spiral CT technology for early lung cancer screening has gained enormous momentum in the past 5 years. The EU-US Spiral CT Collaboration was initiated in 2001 in Liverpool, and subsequent meetings throughout Europe have resulted in the development of collaborative protocols and minimal data sets that provide a mechanism for the different trial groups to work together, with the ultimate aim to pool results. Considerable progress has been made with major national screening trials in the U.S. and Europe, which include IELCAP, NLST, and NELSON. The major objective of this international collaboration is the planned cross-analysis of the individual studies after they are reported. The EU-US researchers have agreed to a number of long-term objectives and to explore strategic areas for harmonization of complementary investigations
0+ → 0- Excitations in 16-O with 200 MeV Proton Inelastic Scattering
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Measurement of the Cross Sections and Analyzing Powers for Transitions in 58-Ni Using 200 MeV Proton Scattering
This research was sponsored by the National Science Foundation Grant NSF PHY-931478
Near-threshold Production in Heavy-ion Collisions
Within a hadronic transport model we study in detail contributions to kaon
yields and momentum spectra from various baryon (resonance)-baryon (resonance)
and interactions in heavy-ion collisions at beam energies near the
free-space kaon production threshold. It is found that the finite lifetime of
baryon resonances affects significantly the shape of kaon spectra, and the high
energy parts of the kaon spectra are dominated by kaons from processes. resonances are found to contribute
about 10\% to the kaon yield. Effects of boosting the Fermi momentum
distributions of the two colliding nuclei into their center of mass frame,
centrality of the reaction as well as the nuclear equation of state on kaon
yields and spectra are also discussed. Model calculations on ,
and spectra for the reaction of Au+Au at GeV are
compared with the experimental data from the KaoS collaboration.Comment: 18 pages, 11 figures available upon request. TAMU preprint #940403
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