12,548 research outputs found
A Monte-Carlo generator for statistical hadronization in high energy e+e- collisions
We present a Monte-Carlo implementation of the Statistical Hadronization
Model in e+e- collisions. The physical scheme is based on the statistical
hadronization of massive clusters produced by the event generator Herwig within
the microcanonical ensemble. We present a preliminary comparison of several
observables with measurements in e+e- collisions at the Z peak. Although a fine
tuning of the model parameters is not carried out, a general good agreement
between its predictions and data is found.Comment: 19 pages, 28 figures, 6 tables. v2: added sections on comparison
between the Statistical Hadronization Model and the Cluster Model and on the
interplay between Herwig cluster splitting algorithm and Statistical
Hadronization Model predictions. Fixed typos and references added. Version
accepted for publication in EPJ
B Physics at the Z0 Resonance
B physics results from e+ e- annihilation at the Z0 resonance are reviewed. A
vast program is summarised, including the study of B+, B0d, B0s and b baryon
lifetimes, the time dependence of B0d and B0s oscillations, the width
difference in the B0s system, and the measurements of the magnitudes of the CKM
matrix elements Vcb and Vub.Comment: 17 pages, 8 figures, presented at the UK Phenomenology Workshop on
Heavy Flavour and CP Violation, 17-22 September 200
Dimensionamento de sistemas de aquecimento em pisos elétricos para frangos de corte.
bitstream/item/58327/1/CUsersPiazzonDocuments276.pd
Statistical bounds on the dynamical production of entanglement
We present a random-matrix analysis of the entangling power of a unitary
operator as a function of the number of times it is iterated. We consider
unitaries belonging to the circular ensembles of random matrices (CUE or COE)
applied to random (real or complex) non-entangled states. We verify numerically
that the average entangling power is a monotonic decreasing function of time.
The same behavior is observed for the "operator entanglement" --an alternative
measure of the entangling strength of a unitary. On the analytical side we
calculate the CUE operator entanglement and asymptotic values for the
entangling power. We also provide a theoretical explanation of the time
dependence in the CUE cases.Comment: preprint format, 14 pages, 2 figure
Comportamento de frangos de corte em sistemas de aquecimento.
bitstream/item/58329/1/CUsersPiazzonDocuments274.pd
Avaliação de isolantes térmicos com potencial uso em aviários.
Projeto/Plano de Ação: 03.07.94.900-04
Effect of Charged Scalar Loops on Photonic Decays of a Fermiophobic Higgs
Higgs bosons with very suppressed couplings to fermions ("Fermiophobic Higgs
bosons", h_f) can decay to two photons (\gamma\gamma) with a branching ratio
significantly larger than that expected for the Standard Model Higgs boson for
m_{h_f}<150 GeV. Such a particle would give a clear signal at the LHC and can
arise in the Two Higgs Doublet Model (type I) in which h_f -> \gamma\gamma is
mediated by W^+ and charged Higgs boson (H^+) loops. We show that the H^+ loops
can cause both constructive and destructive contributions with a magnitude
considerably larger than the anticipated precision in the measurement of the
photonic decay channel at future hadron and lepton colliders.Comment: 18 pages, 5 figures, clarifications added, one reference added,
accepted by Physical Review
Strong Coupling Constant from Scaling Violations in Fragmentation Functions
We present a new determination of the strong coupling constant alpha_s
through the scaling violations in the fragmentation functions for charged
pions, charged kaons, and protons. In our fit we include the latest e+e-
annihilation data from CERN LEP1 and SLAC SLC on the Z-boson resonance and
older, yet very precise data from SLAC PEP at center-of-mass energy sqrt(s)=29
GeV. A new world average of alpha_s is given.Comment: 10 pages, 3 eps figue
Cortina amarela e azul, programas de luz quase contínuo e intermitente na produção de frangos de corte.
bitstream/item/124522/1/CIT53-cortina-azul-amarela-programas-luz-frangos-corte.pdfProjeto/Plano de Ação: 03.07.94.900-04
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