4,406 research outputs found
Fractal diffusion coefficient from dynamical zeta functions
Dynamical zeta functions provide a powerful method to analyze low dimensional
dynamical systems when the underlying symbolic dynamics is under control. On
the other hand even simple one dimensional maps can show an intricate structure
of the grammar rules that may lead to a non smooth dependence of global
observable on parameters changes. A paradigmatic example is the fractal
diffusion coefficient arising in a simple piecewise linear one dimensional map
of the real line. Using the Baladi-Ruelle generalization of the
Milnor-Thurnston kneading determinant we provide the exact dynamical zeta
function for such a map and compute the diffusion coefficient from its smallest
zero.Comment: 8 pages, 2 figure
Performance of a C4F8O Gas Radiator Ring Imaging Cherenkov Detector Using Multi-anode Photomultiplier Tubes
We report on test results of a novel ring imaging Cherenkov (RICH) detection
system consisting of a 3 meter long gaseous C4F8O radiator, a focusing mirror,
and a photon detector array based on Hamamatsu multi-anode photomultiplier
tubes. This system was developed to identify charged particles in the momentum
range from 3-70 GeV/c for the BTeV experiment.Comment: 28 pages, 23 figures, submitted to Nuclear Instruments and Method
The Cleo Rich Detector
We describe the design, construction and performance of a Ring Imaging
Cherenkov Detector (RICH) constructed to identify charged particles in the CLEO
experiment. Cherenkov radiation occurs in LiF crystals, both planar and ones
with a novel ``sawtooth''-shaped exit surface. Photons in the wavelength
interval 135--165 nm are detected using multi-wire chambers filled with a
mixture of methane gas and triethylamine vapor. Excellent pion/kaon separation
is demonstrated.Comment: 75 pages, 57 figures, (updated July 26, 2005 to reflect reviewers
comments), to be published in NIM
The Cleo III Ring Imaging Cherenkov Detector
The CLEO detector has been upgraded to include a state of the art particle
identification system, based on the Ring Imaging Cherenkov Detector (RICH)
technology, in order to take data at the upgraded CESR electron positron
collider. The expected performance is reviewed, as well as the preliminary
results from an engineering run during the first few months of operation of the
CLEO III detector.Comment: 5 pages, 2 Figures Talk given by M. Artuso at 8th Pisa Meeting on
Advanced Detectors, May 200
Accelerating cycle expansions by dynamical conjugacy
Periodic orbit theory provides two important functions---the dynamical zeta
function and the spectral determinant for the calculation of dynamical averages
in a nonlinear system. Their cycle expansions converge rapidly when the system
is uniformly hyperbolic but greatly slowed down in the presence of
non-hyperbolicity. We find that the slow convergence can be associated with
singularities in the natural measure. A properly designed coordinate
transformation may remove these singularities and results in a dynamically
conjugate system where fast convergence is restored. The technique is
successfully demonstrated on several examples of one-dimensional maps and some
remaining challenges are discussed
Spectral Characterization of Anomalous Diffusion of a Periodic Piecewise Linear Intermittent Map
For a piecewise linear version of the periodic map with anomalous diffusion,
the evolution of statistical averages of a class of observables with respect to
piecewise constant initial densities is investigated and generalized
eigenfunctions of the Frobenius-Perron operator are explicitly derived. The
evolution of the averages is controlled by real eigenvalues as well as
continuous spectra terminating at the unit circle. Appropriate scaling limits
are shown to give a normal diffusion if the reduced map is in the stationary
regime with normal fluctuations, a L\'evy flight if the reduced map is in the
stationary regime with L\'evy-type fluctuations and a transport of ballistic
type if the reduced map is in the non-stationary regime.Comment: submitted to Physica D (CHAOTRAN conference proceedings
Measurement of B(D^0 → K^-π^+) Using Partial Reconstruction of B̅ → D^(*+)Xℓ^-ν̅
We present a measurement of the absolute branching fraction for D^0→K^-π^+ using the reconstruction of the decay chain B̅ →D^(*+)Xℓ^-ν̅ , D^(*+)→D^0π^+ where only the lepton and the low-momentum pion from the D^(*+) are detected. With data collected by the CLEO II detector at the Cornell Electron Storage Ring, we have determined B(D^0→K^-π^+) = [3.81±0.15(stat)±0.16(syst)]%
Bifractality of the Devil's staircase appearing in the Burgers equation with Brownian initial velocity
It is shown that the inverse Lagrangian map for the solution of the Burgers
equation (in the inviscid limit) with Brownian initial velocity presents a
bifractality (phase transition) similar to that of the Devil's staircase for
the standard triadic Cantor set. Both heuristic and rigorous derivations are
given. It is explained why artifacts can easily mask this phenomenon in
numerical simulations.Comment: 12 pages, LaTe
Monte Carlo Studies of a Novel LiF Radiator for RICH Detectors
We show that a multifaceted LiF radiator produces more Cherenkov light and
has better resolution per photon than a flat radiator slab when used in a ring
imaging Cherenkov counter. Such a system is being considered for the CLEO III
upgrade.Comment: 9 page
Measurements of Branching Fractions for Electromagnetic Transitions Involving the χ_{bJ}(1P) States
Using 9.32, 5.88 million Upsilon(2S,3S) decays taken with the CLEO-III detector, we obtain five product branching fractions for the exclusive processes Upsilon(2S) =\u3e gamma chi_{b0,1,2}(1P) =\u3e gamma gamma Upsilon(1S) and Upsilon(3S) =\u3e gamma chi_{b1,2}(1P) =\u3e gamma gamma Upsilon(1S). We observe the transition chi_{b0}(1P) =\u3e gamma Upsilon(1S) for the first time. Using the known branching fractions for B[Upsilon(2S) =\u3e gamma chi_{bJ}(1P)], we extract values for B[chi_{bJ}(1P) =\u3e gamma Upsilon(1S)] for J=0, 1, 2. In turn, these values can be used to unfold the Upsilon(3S) product branching fractions to obtain values for B[Upsilon(3S) =\u3e gamma chi_{b1,2}(1P) for the first time individually. Comparison of these with each other and with the branching fraction B[Upsilon(3S) =\u3e gamma chi_{b0}] previously measured by CLEO provides tests of relativistic corrections to electric dipole matrix elements
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