Power corrections in heavy-to-light decays at large recoil energy

I briefly present recent work on QCD power corrections in heavy-to-light meson decays, using an effective field theory approach.Comment: 4 pages, 1 figure. Talk given at ICHEP 2002, Amsterdam, July 200

The Yuima-e as Theatre of the State

This article analyzes a twelfth-century session of the Yuima-e at Kofukuji as a stage of history to determine the institutional and factional background of its participants. In order to do this, the format of the Yuima-e as it was held in the twelfth century is presented, followed by a study of primary materials related to the 1196 session of this annual ritual. The article then examines the Sanne joichiki, the personal notes of the Todaiji monk Sosho, and diaries, to conclude that these sessions can indeed be considered "theatres of the state" in which the connection between Kuroda Toshio's concepts of kenmon and kenmitsu taisei can be found

Nuclear Multifragmentation Critical Exponents

We show that the critical exponents of nuclear multi-fragmentation have not been determined conclusively yet.Comment: 3 pages, LaTeX, one postscript figure appended, sub. to Phys.Rev.Lett. as a commen

Maximal entropy random networks with given degree distribution

Using a maximum entropy principle to assign a statistical weight to any graph, we introduce a model of random graphs with arbitrary degree distribution in the framework of standard statistical mechanics. We compute the free energy and the distribution of connected components. We determine the size of the percolation cluster above the percolation threshold. The conditional degree distribution on the percolation cluster is also given. We briefly present the analogous discussion for oriented graphs, giving for example the percolation criterion.Comment: 22 pages, LateX, no figur

Random incidence matrices: moments of the spectral density

We study numerically and analytically the spectrum of incidence matrices of random labeled graphs on N vertices : any pair of vertices is connected by an edge with probability p. We give two algorithms to compute the moments of the eigenvalue distribution as explicit polynomials in N and p. For large N and fixed p the spectrum contains a large eigenvalue at Np and a semi-circle of "small" eigenvalues. For large N and fixed average connectivity pN (dilute or sparse random matrices limit), we show that the spectrum always contains a discrete component. An anomaly in the spectrum near eigenvalue 0 for connectivity close to e=2.72... is observed. We develop recursion relations to compute the moments as explicit polynomials in pN. Their growth is slow enough so that they determine the spectrum. The extension of our methods to the Laplacian matrix is given in Appendix. Keywords: random graphs, random matrices, sparse matrices, incidence matrices spectrum, momentsComment: 39 pages, 9 figures, Latex2e, [v2: ref. added, Sect. 4 modified

Why Use Sobolev Metrics on the Space of Curves

We study reparametrization invariant Sobolev metrics on spaces of regular curves. We discuss their completeness properties and the resulting usability for applications in shape analysis. In particular, we will argue, that the development of efficient numerical methods for higher order Sobolev type metrics is an extremely desirable goal

Core percolation in random graphs: a critical phenomena analysis

We study both numerically and analytically what happens to a random graph of average connectivity "alpha" when its leaves and their neighbors are removed iteratively up to the point when no leaf remains. The remnant is made of isolated vertices plus an induced subgraph we call the "core". In the thermodynamic limit of an infinite random graph, we compute analytically the dynamics of leaf removal, the number of isolated vertices and the number of vertices and edges in the core. We show that a second order phase transition occurs at "alpha = e = 2.718...": below the transition, the core is small but above the transition, it occupies a finite fraction of the initial graph. The finite size scaling properties are then studied numerically in detail in the critical region, and we propose a consistent set of critical exponents, which does not coincide with the set of standard percolation exponents for this model. We clarify several aspects in combinatorial optimization and spectral properties of the adjacency matrix of random graphs. Key words: random graphs, leaf removal, core percolation, critical exponents, combinatorial optimization, finite size scaling, Monte-Carlo.Comment: 15 pages, 9 figures (color eps) [v2: published text with a new Title and addition of an appendix, a ref. and a fig.

The BaBar Electromagnetic Calorimeter: Status and Performance Improvements

The electromagnetic calorimeter at the BaBar detector, part of the asymmetric B Factory at SLAC, measures photons in the energy range from 20 MeV to 8 GeV with high resolution. The current status of the calorimeter, now in its seventh year of operation, is being presented, as well as details on improvements made to the analysis code during the last years.Comment: 6 pages, 15 figures, presented at the 2005 IEEE Nuclear Science Symposium and submitted to the Conference Proceedings of the 2005 IEEE Nuclear Science Symposiu