14072620
Light Meson Mass Spectrum from Gauge Fields on Supergravity Backgrounds
We propose that the spectrum of light mesons (the $\pi$ and $\rho$, together with their radial excitations) can be calculated in the limit of vanishing light quark masses by studying gauge theory (open string theory) on suitable higher dimensional background geometries. Using the metric proposed by Witten for glueball calculations as a paradigmatic example, we find a spectrum which is in startlingly good agreement with the masses tabulated by the Particle Data Group. These calculations have only one free parameter, corresponding to the overall mass scale. We make predictions for the next several particles in the spectrum.
119471275
A Chern-Simons-like action for closed-string field theory
A Chern-Simons-like action is proposed for closed-string field theory. The action involves auxiliary fields of arbitrary ghost number and is defined in terms of the closed-string operations integral , Q and, analogous to those introduced by Witten (1986) in the construction of open-string field theory. The action is an extension of one proposed for free closed strings and bears a formal relationship to 2+1 gravity analogous to that between open-string field theory and (2+1)-dimensional Yang-Mills theory.
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.
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.
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.
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.
15184441
A High-Resolution Mosaic of Molecular Gas in Stephan’s Quintet
We present high-resolution 12CO J = 1-0 observations of the molecular gas in the Hickson compact group Stephan's Quintet (HCG 92). Our observations consist of multiple pointings and mosaics covering all the regions where CO and star formation have been detected. Within the 100'' field of view centered on the easternmost tidal tail, we detect three clumps of emission that may be partially resolved at our resolution of 8''; two of these are new detections not previously seen in ISM studies of this region. Two of these clumps lie in the optical tidal tail, while the third lies to the southeast and is coincident with a large H I feature, but it does not correspond to any features at other wavelengths. We also tentatively detect CO emission from the star-forming regions in the "old tail" corresponding to recent star formation activity detected in recent UV and Hα observations. Observations of the rest of the compact group do not show detections, even though strong emission was detected with single-dish telescopes, which suggests that the CO emission originates from a diffuse molecular gas cloud or from at least three separate clumps with separations greater than around 3 kpc.