64,843 research outputs found

    B-physics: new states, rare decays and branching ratios in CDF

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    We present results and prospects for searches for rare B and D meson decays with final state dimuons, including B_s\to\mu\mu, B_d\to\mu\mu, and D\to\mu\mu. Upper limits on the branching fractions are compared to previous CDF measurements, recent results from the B factories and theoretical expectations. We also report on new measurements of production and decay properties of the X(3872) particle, discovered in 2003 by the Belle Collaboration. New results on the measurement of the relative branching fraction for the Cabibbo suppressed decay B^+\to J/\psi\pi^+ Br(B^+\to J/\psi\pi^+)/Br(B^+\to J/\psi K^+) are presented too. The presented results are based on the analyses of 70 to 220 pb^-1 of data collected by the CDF II detector in p\bar p collisions at \sqrt{s} = 1.96 GeV at Fermilab Tevatron.Comment: Presented at the 6th International Conference on Hyperons, Charm & Beauty Hadrons (BEACH04), Chicago, IL, June 27 - July 03 2004. 5 page

    Chaotic Electron Motion in Superlattices. Quantum-Classical Correspondence of the Structure of Eigenstates and LDOS

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    We investigate the classical-quantum correspondence for particle motion in a superlattice in the form of a 2D channel with periodic modulated boundaries. Its classical dynamics undergoes the generic transition to chaos of Hamiltonian systems as the amplitude of the modulation is increased. We show that for strong chaotic motion, the classical counterpart of the structure of eigenstates (SES) in energy space reveals an excellent agreement with the quantum one. This correspondence allows us to understand important features of the SES in terms of classical trajectories. We also show that for typical 2D modulated waveguides there exist, at any energy range, extremely localized eigenstates (in energy) which are practically unperturbed by the modulation. These states contribute to the strong fluctuations around the classical SES. The approach to the classical limit is discussed.Comment: 4 pages, 4 figure

    Track Extrapolation and Distribution for the CDF-II Trigger System

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    The CDF-II experiment is a multipurpose detector designed to study a wide range of processes observed in the high energy proton-antiproton collisions produced by the Fermilab Tevatron. With event rates greater than 1MHz, the CDF-II trigger system is crucial for selecting interesting events for subsequent analysis. This document provides an overview of the Track Extrapolation System (XTRP), a component of the CDF-II trigger system. The XTRP is a fully digital system that is utilized in the track-based selection of high momentum lepton and heavy flavor signatures. The design of the XTRP system includes five different custom boards utilizing discrete and FPGA technology residing in a single VME crate. We describe the design, construction, commissioning and operation of this system.Comment: 34 pages, 9 figures, submitted to Nucl.Inst.Meth.

    Spherical CR Dehn Surgery

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    Consider a three dimensional cusped spherical CR\mathrm{CR} manifold MM and suppose that the holonomy representation of π1(M)\pi_1(M) can be deformed in such a way that the peripheral holonomy is generated by a non-parabolic element. We prove that, in this case, there is a spherical CR\mathrm{CR} structure on some Dehn surgeries of MM. The result is very similar to R. Schwartz's spherical CR\mathrm{CR} Dehn surgery theorem, but has weaker hypotheses and does not give the unifomizability of the structure. We apply our theorem in the case of the Deraux-Falbel structure on the Figure Eight knot complement and obtain spherical CR\mathrm{CR} structures on all Dehn surgeries of slope −3+r-3 + r for r∈Q+r \in \mathbb{Q}^{+} small enough.Comment: 27 page

    [Review of] Gail Pellet and Stanley Nelson (producers and directors). Shattering the Silences

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    Our silence will not protect us, poet and feminist Audre Lorde has written, and broken silences recur with startling clarity in Shattering the Silences. The video documentary features professors of color from across the nation discussing their experiences as scholars, as people of color in predominantly white institutions, as women of color in predominantly male departments, and as husbands, mentors, and for some, as the first in their family to pursue a life in academia. Each story is compelling, sometimes painful, and always poignant
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