6,890 research outputs found
Four Pion Final States with Tagged Photons at Electron Positron Colliders
A Monte Carlo generator has been constructed to simulate the reaction e^+e^-
\to \gamma + 4 \pi, where the photon is assumed to be observed in the detector.
Only initial state radiation is considered. Additional collinear photon
radiation has been incorporated with the technique of structure functions.
Predictions are presented for cms energies of 1GeV, 3GeV and 10GeV,
corresponding to the energies of DAPHNE, BEBC and of B-meson factories. The
event rates are sufficiently high to allow for a precise measurement of R(Q^2)
in the region of Q between approximately 1GeV and 2.5GeV. For the construction
of the program we employ isospin relations between the amplitudes governing tau
decays into four pions and electron positron annihilation into four pions.
Estimates of the kinematic breaking of these isospin relations as a consequence
of the \pi^- -- \pi^0 mass difference are given.Comment: LATEX, 27 pages, 9 figures, discussion of the kinematic breaking of
isospin relations extended, typos corrected, some formulations change
ESTIMATION OF EMPLOYMENT MULTIPLIERS FOR PLANNING IN OZARKS NONMETROPOLITAN COUNTIES
Labor and Human Capital,
Time-Scale and Noise Optimality in Self-Organized Critical Adaptive Networks
Recent studies have shown that adaptive networks driven by simple local rules
can organize into "critical" global steady states, providing another framework
for self-organized criticality (SOC). We focus on the important convergence to
criticality and show that noise and time-scale optimality are reached at finite
values. This is in sharp contrast to the previously believed optimal zero noise
and infinite time scale separation case. Furthermore, we discover a noise
induced phase transition for the breakdown of SOC. We also investigate each of
the three new effects separately by developing models. These models reveal
three generically low-dimensional dynamical behaviors: time-scale resonance
(TR), a new simplified version of stochastic resonance - which we call steady
state stochastic resonance (SSR) - as well as noise-induced phase transitions.Comment: 4 pages, 6 figures; several changes in exposition and focus on
applications in revised versio
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