BaBar B Decay Results

Data from the first run of the BaBar detector at the PEP II accelerator are presented. Measurements of many rare B decay modes are now possible using the large data sets currently being collected by BaBar. An overview of analysis techniques and results on data collected in 2000 are described.Comment: 16 pages, 35 figures. Submission to Lepton-Photon 2001 Rome conference proceeding

Spinor model of a perfect fluid

Different characteristic of matter influencing the evolution of the Universe has been simulated by means of a nonlinear spinor field. We have considered two cases where the spinor field nonlinearity occurs either as a result of self-action or due to the interaction with a scalar field.Comment: 5 pages, some misprints are corrected, some new expressions are adde

Topological expansion and boundary conditions

In this article, we compute the topological expansion of all possible mixed-traces in a hermitian two matrix model. In other words we give a recipe to compute the number of discrete surfaces of given genus, carrying an Ising model, and with all possible given boundary conditions. The method is recursive, and amounts to recursively cutting surfaces along interfaces. The result is best represented in a diagrammatic way, and is thus rather simple to use.Comment: latex, 25 pages. few misprints correcte

Charged Particle Multiplicities in Ultra-relativistic Au+Au and Cu+Cu Collisions

The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5 to 179.5 deg. corresponding to |eta|<5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.Comment: Proceedings of "Lake Louise Winter Institute 2006", Lake Louise, Alberta, Canada, February 17-23, 2006, World Scientific 5 pages, 3 figure

Real and Image Fields of a Relativistic Bunch

We derive analytical expressions for external fields of a charged relativistic bunch with a circular cross section. At distances far from the bunch, the field reduces to the relativistic modified Coulomb form and in the near region, reproduce the external fields of a continuous beam. If the bunch is surrounded by conducting surfaces, the bunch self-fields are modified. Image fields generated by a bunch between two parallel conducting planes are studied in detail. Exact summation of image fields by the direct method invented by Laslett allows the infinite series to be represented in terms of elementary trigonometric functions.Comment: 10 page

Parallel hybrid textures of lepton mass matrices

We analyse the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total sixty parallel hybrid texture structures can be grouped into twelve classes, and all the hybrid textures in the same class have identical physical implications. We examine all the twelve classes under the assumption of non-factorizable phases in the neutrino mass matrix. Five out of the total twelve classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1-3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.Comment: Physical Review D (To appear