115616794
Charmless semileptonic decays of B mesons
The authors have used the CLEO II detector at the CESR storage ring to study the endpoint region of the B-meson semileptonic momentum spectrum. Lepton production above the kinematic limit for b{r_arrow}cl{nu} is confirmed, although at a level which is smaller than has been observed previously. Model-dependent estimates os the ratio {vert_bar}V{sub ub}{vert_bar}/{vert_bar}V{sub cb}{vert_bar} will be reported.
115616794
Charmless semileptonic decays of B mesons
The authors have used the CLEO II detector at the CESR storage ring to study the endpoint region of the B-meson semileptonic momentum spectrum. Lepton production above the kinematic limit for b{r_arrow}cl{nu} is confirmed, although at a level which is smaller than has been observed previously. Model-dependent estimates os the ratio {vert_bar}V{sub ub}{vert_bar}/{vert_bar}V{sub cb}{vert_bar} will be reported.
108864186
MINOS near-detector coil design
The 980-ton MINOS near detector will be installed in the new NuMI near hall at 100m below grade at Fermilab. It will be assembled from 282 1-inch thick steel plates. The planes are made from low carbon (1006), hot rolled steel and are toroidally magnetized. Each plane will be hung by two 'ears', which are extensions of the octagonal plane structure, similar to the hanging files in a file drawer. The plates have a center-to-center spacing of 5.94 cm. This document has been prepared for the 8/99 Conceptual Design Review of the MINOS near detector coil. It's main goal is to provide a set of references to previous documents and to assemble various design drawings and engineering calculations that have not been included in previous technical memos. It also provides some background material relevant for the coil implementation. Much of the text for this document is edited from the MINOS Detectors Technical Design Report.
120224392
The effects of neutron irradiation on multi-pixel hybrid photodiode tubes
Abstract The effects of neutron irradiation on a multi-pixel hybrid photodiode tube (HPD) were studied. The HPD underwent an integrated fluence of 10 13 neutrons cm 2 from a 252 Cf source. Increased leakage currents were observed during this irradiation, consistent with that observed from bare silicon detectors. The HPD was observed to be fully operational, with acceptable leakage currents, at the fluences expected during the lifetime of the CMS experiment. After the full dosage, small intrapixel inhomogeneities were observed in the HPD's response. The origins of these inhomogeneities and methods to mitigate the radiation damage were investigated.
42871335
Search for exclusive b-->u semileptonic decays of B mesons.
Using a sample of 935000 BB pairs collected with the CLEO-II detector at the Cornell Storage Ring, we have obtained upper limits on the branching ratios for the b→ul - υ#58 processes B - →ωl - υ#58, B - →ρ 0 l - υ#58, and B 0 →ρ + l - υ#58. The combined result using the relationships among the widths for these three modes is B(B - →ρ 0 l - υ#58)<(1.6-2.7)×10 -4 at 90% C. L., where the range of value to model dependence of the detection efficiencies. These measurements yield the limits |V ub /V cb |<0.08-0.13
119509119
The MINOS Magnets
The MINOS long baseline neutrino oscillation experiment will consists of two magnetized tracking calorimeters one on the Fermilab site and one in Minnesota. This paper summarizes the design, magnetic performance, and status of the MINOS magnets.
118182794
QUANTUM GRAVITY AND QUANTUM GROUPS
First order gravity in 2 + 1 space-time dimensions with cosmological constant Λ and spatial Riemann surfaces is considered. The representations of the fundamental group satisfy an algebra related to the quantum group SU(2)q. The Poincare theory appears as the limit Λ → 0.
120746763
The group manifold hamiltonian for supergravity
Abstract We establish the correspondence between the covariant canonical formalism for N = 1 supergravity and the component formalism. Throughout we use a compound Poincare notation extended to include spinor components, and find the structure of the hamiltonian and constraint algebra identical with that of pure gravity, differing only in the range of the compound indices.
16014194
The interaction of a giant planet with a disc with MHD turbulence - I. The initial turbulent disc models
This is the first of a series of papers aimed at developing and interpreting simulations of protoplanets interacting with turbulent accretion discs. In this first paper we study the turbulent disc models prior to the introduction of a perturbing protoplanet. We study cylindrical disc models in which a central domain is in Keplerian rotation and unstable to the magnetorotational instability. Models of varying disc size and aspect ratio H/r are considered with magnetic fields having zero net flux. We relate the properties of the turbulent models to classical viscous disc theory. All models were found to attain a turbulent state in their Keplerian domains with volume averaged stress parameter α ∼ 5 × 10 −3 . At any particular time the vertically and azimuthally averaged value exhibited large fluctuations in radius. However, an additional time average over periods exceeding three orbital periods at the outer boundary of the Keplerian domain resulted in a more smoothly varying quantity with radial variations within a factor of 2 or so. The vertically and azimuthally averaged radial velocity showed much larger spatial and temporal fluctuations, requiring additional time averaging for at least seven to eight orbital periods at the outer boundary of the Keplerian domain to limit them. Comparison with the value derived from the averaged stress using viscous disc theory yielded schematic agreement for feasible averaging times but with some indication that the effects of residual fluctuations remained. The behaviour described above must be borne in mind when considering laminar disc simulations with anomalous Navier‐Stokes viscosity. This is because the operation of a viscosity, as in classical viscous disc theory with anomalous viscosity coefficient, cannot apply to a turbulent disc undergoing rapid changes due to external perturbation. The classical theory can only be used to describe the time averaged behaviour of the parts of the disc that are in a statistically steady condition long enough for appropriate averaging to be carried out.
119470781
Some Applications of the ADM Formalism
The ADM Formalism is discussed in the context of 2+1--dimensional gravity, uniting two areas of relativity theory in which Stanley Deser has been particularly active. For spacetimes with topology R x T^2 the partially reduced and fully reduced ADM formalism are related and quantized, and the role of "large diffeomorphisms" (the modular group) in the quantum theory is illustrated.
16044360
Classical and quantum geometry of moduli spaces in three-dimensional gravity
We describe some results concerning the phase space of 3-dimensional Einstein gravity when space is a torus and with negative cosmological constant. The approach uses the holonomy matrices of flat SL(2,R) connections on the torus to parametrise the geometry. After quantization, these matrices acquire noncommuting entries, in such a way that they satisfy q-commutation relations and exhibit interesting geometrical properties. In particular they lead to a quantization of the Goldman bracket.