124532074
FAD, DCCs and Minimax
SummaryThere is a need to more fully exploit the intrinsic diversity of hadron-hadron collisions. The Full-Acceptance Detector (FAD) initiative was a proposal to do so at the SSC. With the demise of the SSC, it is useful to review the motivation for FAD, and the prospects for pursuing Full-Acceptance Physics at present and future hadron colliders. Particular attention is paid to T864 (MiniMax) at Fermilab, a chiral condensate search which has developed out the FAD enterprise.
33049133
Vacuum structure, zero modes, and the effective potential in light-cone quantization.
A Hamiltonian formalism for the calculation of the usual effective potential is presented in the context of scalar field theory. When applied in the context of light-cone quantization, we find contributions at [ital k][sup +]=0 which are missed by standard light-cone infrared regularizations. We present a (time-dependent) regularization of the Hamiltonian which correctly incorporates these contributions at the one-loop level. We briefly discuss the implications of these findings for the more general program of diagonalizing the light-cone Hamiltonian.
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.
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.
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.
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.
14127729
THE ORIGIN OF THE DUST ARCH IN THE HALO OF NGC 4631: AN EXPANDING SUPERBUBBLE?
We study the nature and the origin of the dust arch in the halo of the edge-on galaxy NGC 4631 detected by Neininger & Dumke. We present CO observations made using the new on-the-fly mapping mode with the Five College Radio Astronomy Observatory 14 m telescope and find no evidence for CO emission associated with the dust arch. Our examination of previously published H I data shows that, if previous assumptions about the dust temperature and gas/dust ratio are correct, then there must be molecular gas associated with the arch, below our detection threshold. If this is true, then the molecular mass associated with the dust arch is between 1.5 × 108 M⊙ and 9.7 × 108 M⊙, and likely toward the low end of the range. A consequence of this is that the maximum allowed value for the CO-to-H2 conversion factor is 6.5 times the Galactic value, but most likely closer to the Galactic value. The kinematics of the H I apparently associated with the dust arch reveals that the gas here is not part of an expanding shell or outflow but is instead two separate features (a tidal arm and a plume of H I sticking out into the halo) that are seen projected together and appear as a shell. Thus there is no connection between the dust "arch" and the hot X-ray–emitting gas that appears to surround the galaxy.