A high resolution search for the tensor glueball candidate [xi] (2230) Crystal Barrel Collaboration

We report results of a high resolution search for the tensor glueball candidate ξ(2230) in a p̄p formation experiment. π0π0 and ηη decay channels were measured in a scan of the mass region 2220 MeV to 2240 MeV. No evidence for the existence of ξ(2230) was found. 95% confidence upper limits for the possible existence of ξ are presented

Recent results from Crystal Barrel in p‾p→KKπ\overline{p} p \to K K \pi and ω4γ\omega 4 \gamma

Recent results from the Crystal Barrel experiment in KK pi which bear on f/sub 0/(1500) and the controversial f/sub J/(1710) are presented. If the spin of the latter is 0, both states compete for being the scalar glueball. On the other hand, f/sub J/(1710) could be the missing ss of the 0/sup ++/ nonet, or 2/sup ++/. The annihilation channels omega pi /sup 0/ pi /sup 0/ and omega eta pi /sup 0/ have been analyzed with increased statistics. The ingredients needed to describe the Dalitz plot are discussed. (19 refs)

Statistical geometry of hard particles on a sphere

We present a Monte Carlo study of a two-dimensional system of hard particles embedded on the surface of a sphere. Thermodynamic and structural evidence of an ordering phase transition is found at high densities in spite of the frustration induced on the hexagonal covering by the peculiar topology of the host surface. The nature of this transition is analyzed and contrasted with the fluid-solid transition occuring in a flat geometry

Statistical geometry of hard particles on a sphere: analysis of defects at high density

We analyse the geometry of the solid phase shaped by densely packed hard calottes on a sphere. We show that in this phase topological defects are not distributed at random over the surface but segregate into clusters that give rise to an upper level of organization in the form of a superstructure with icosahedral symmetry

Packing patterns of silica nanoparticles on surfaces of armored polystyrene latex particles

Fascinating packing patterns of identical spherical and discotic objects on curved 3 surfaces occur readily in nature and, and S-layer proteins on outer cell science. Examples include C-60 fullerenes,(1,2)13-atom cuboctahedral metal clusters, membranes.(4) Numerous situations with surface-arranged objects of variable size also exist, such as the lenses on insect eyes, biomineralized shells on coccolithophorids,(5) and solid-stabilized emulsion droplets(6) and bubbles.(7) The influence of size variations on these packing patterns, however, is studied sparsely. Here we investigate the packing of nanosized silica particles on the surface of polystyrene latex particles fabricated by Pickering miniemulsion polymerization of submicrometer-sized armored monomer droplets. We are able to rationalize the experimental morphology and the nearest-neighbor distribution with the help or Monte Carlo simulations. We show that broadening of the nanoparticle size distribution has pronounced effects on the self-assembled equilibrium packing structures, with original 12-point dislocations or grain-boundary scars gradually fading out