116979191
Symplectic Reduction of the Minimally Coupled Massless Superparticle in D=10
In this study of the Brink-Schwarz superparticle in the presence of background non-abelian gauge field, we derive the D=10 super Yang-Mills curvature constraints by demanding an analog of the Siegel supersymmetry. We then show that, assuming F αβ = 0, the twistor transform proposed by Witten can be described using symplectic reduction.
37539171
Search for disoriented chiral condensate at the Fermilab Tevatron
We present results from MiniMax (Fermilab T-864), a small test/experiment at the Fermilab Tevatron designed to search for the production of a disoriented chiral condensate (DCC) in p-p(bar sign) collisions at {radical}(s)=1.8 TeV in the forward direction, {approx}3.4<{eta}<{approx}4.2. Data, consisting of 1.3x10{sup 6} events, are analyzed using the robust observables developed in an earlier paper. The results are consistent with generic, binomial-distribution partition of pions into charged and neutral species. Limits on DCC production in various models are presented. (c) 2000 The American Physical Society.
120344295
Superspace supergravity from the superstring
Abstract We study a classical superstring propagating in a “curved” (10,16)-dimensional superspace. In this formulation of the string, a local fermionic symmetry is needed to eliminate ghosts from the particle spectrum. By studying the constraint algebra, we show that any background field configuration consistent with this symmetry is equivalent to one which satisfies the full set of supergravity equations.
120159094
Microcanonical cluster approximations
Abstract A method of entropy estimates due to Kikuchi is generalized from Ising systems to Z 2 gauge models. This method is explicitly gauge invariant. The results of the approximation are compared to Monte Carlo data and strong coupling expansions.
120178876
Constraint algebra of open string field theory in midpoint coordinates
Abstract We study the canonical structure of string field theory in midpoint coordinates. We find the constraint algebra, which consists of second class constraints, together with dependent first class constraints. Exploiting properties of the relevant operators, we show that the constraint algebra is the same in the interacting theory as in the free theory, at least on Fock-space states. We discuss the gauge transformations generated by the first class constraints, and show that they can be used to gauge away unphysical fields.
17332592
Analysis of charged-particle–photon correlations in hadronic multiparticle production
In order to analyze data on joint charged-particle/photon distributions from an experimental search (T-864, MiniMax) for disoriented chiral condensate (DCC) at the Fermilab Tevatron collider, we have identified robust observables, ratios of normalized bivariate factorial moments, with many desirable properties. These include insensitivity to many efficiency corrections and the details of the modeling of the primary pion production, and sensitivity to the production of DCC, as opposed to the generic, binomial-distribution partition of pions into charged and neutral species. The relevant formalism is developed and tested in Monte-Carlo simulations of the MiniMax experimental conditions.
16833520
The H I Companions of H II Galaxies and Low Surface Brightness Dwarf Galaxies
I study the VLA H I survey of H II galaxies by Taylor et al. and the VLA H I survey of low surface brightness (LSB) dwarf galaxies by Taylor et al. to investigate the role of galaxy interactions in triggering the bursts of massive star formation seen in H II galaxies. Comparing the two surveys, I find that H II galaxies have companions more than twice as often as LSB dwarfs (p = 0.57 for H II galaxies, compared to p = 0.24 for LSB dwarfs). I examine the completeness of the companion samples detected by the two surveys. For the companions to H II galaxies, the sample is likely complete in the distribution of velocity separations from their parent galaxies but is probably missing some companions at large projected linear separations because of the finite size of the VLA primary beam. For the companions of LSB dwarfs, the small number of detections means their distributions in velocity and linear separation are poorly determined, but the LSB dwarfs were observed with the same observational setup as the H II galaxies, so they will have the same levels of completeness. Because the two samples were observed in exactly the same fashion, there will be no relative bias in the number of companions introduced in this way. In addition, the redshift distributions of the two samples are very similar, so there will not be a distance-related relative bias. Thus, I conclude that the difference in the number of H I rich companions is genuine, and signifies a difference in the local, small-scale environments between the two types of galaxy. I search through published galaxy catalogs to determine number of neighbors each galaxy has outside the area of the VLA observations. At these large separations, the number of neighbors is the same, within the errors, for the two types of galaxy. The high rate of companion occurrence at low separations for H II galaxies relative to LSB dwarfs supports the hypothesis that the bursts of star formation are triggered by galaxy interactions.
15682686
THE SPATIAL DISTRIBUTION OF ATOMIC CARBON EMISSION IN THE GIANT MOLECULAR CLOUD NGC 604-2
We have mapped a giant molecular cloud in the giant H II region NGC 604 in M33 in the 492 GHz 3P1 → 3P0 transition of neutral atomic carbon using the James Clerk Maxwell Telescope. We find the distribution of the [C I] emission to be asymmetric with respect to the CO J = 1 → 0 emission, with the peak of the [C I] emission offset toward the direction of the center of the H II region. In addition, the line ratio I/ICO is highest (~0.2) facing the H II region and lowest (0.1) away from it. These asymmetries indicate an edge-on morphology where the [C I] emission is strongest on the side of the cloud facing the center of the H II region and not detected at all on the opposite side This suggests that the sources of the incident flux creating C from the dissociation of CO are the massive stars of the H II region. The lowest line ratios are similar to what is observed in Galactic molecular clouds, while the highest are similar to starburst galaxies and other regions of intense star formation. The column density ratio, N(C)/N(H2) is a few ×10-6, in general agreement with models of photodissociation regions.