126036591
Lorentz invariance and the group manifold approach
5325226
A QUANTUM GOLDMAN BRACKET FOR LOOPS ON SURFACES
In the context of (2+1)–dimensional gravity, we use holonomies of constant connections which generate a q–deformed representation of the fundamental group to derive signed area phases which relate the quantum matrices assigned to homotopic loops. We use these features to determine a quantum Goldman bracket (commutator) for intersecting loops on surfaces, and discuss the resulting quantum geometry.
120048132
Canonical normal coordinates
We examine the advantages and disadvantages of fixing the coordinate gauge to be that of the Riemann normal coordinates by applying the Dirac formalism for constrained canonical systems in general relativity.
123882078
Canonical Theories from the Group Manifold
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.
118956967
Constants of the Motion and the Quantum Modular Group in (2+1) - Dimensional Gravity
Constants of motion are calculated for 2+1 dimensional gravity with topology R \times T^2 and negative cosmological constant. Certain linear combinations of them satisfy the anti - de Sitter algebra so(2,2) in either ADM or holonomy variables. Quantisation is straightforward in terms of the holonomy parameters, and the modular group is generated by these conserved quantities. On inclusion of the Hamiltonian three new global constants are derived and the quantum algebra extends to the conformal algebra so(2,3).
122041574
Multi-pixel hybrid photodiode tubes for the CMS hadron calorimeter
Abstract Avalanche Photodiodes and 7-channel HPDs from DEP were installed on a prototype CMS HCAL and their response to muons, electrons and pions was measured in a test beam. DC response to a radioactive source used to calibrate the tiles was also studied. Increase in leakage current in the HPD from an integrated dose of 10 13 neutrons/cm 2 was observed using a Cf source.
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.