17,387 research outputs found
Test of QEDPS: A Monte Carlo for the hard photon distributions in e+ e- annihilation proecss
The validity of a photon shower generator QEDPS has been examined in detail.
This is formulated based on the leading-logarithmic renormalization equation
for the electron structure function and it provides a photon shower along the
initial e+-. The main interest in the present work is to test the reliability
of the generator to describe a process accompanying hard photons which are
detected. For this purpose, by taking the HZ production as the basic reaction,
the total cross section and some distributions of the hard photons are compared
between two cases that these photons come from either those generated by QEDPS
or the hard process e+e- -> H Z gamma gamma. The comparison performed for the
single and the double hard photon has shown a satisfactory agreement which
demonstrated that the model is self-consistent.Comment: 22 pages, 4 Postscript figures, LaTeX, uses epsf.te
A QED Shower Including the Next-to-leading Logarithm Correction in e+e- Annihilation
We develop an event generator, NLL-QEDPS, based on the QED shower including
the next-to-leading logarithm correction in the e^+e^- annihilation. The shower
model is the Monte Carlo technique to solve the renormalization group equation
so that they can calculate contributions of alpha^m log^n(S/m_e^2) for any m
and n systematically. Here alpha is the QED coupling, m_e is the mass of
electron and S is the square of the total energy in the e^+e^- system. While
the previous QEDPS is limited to the leading logarithm approximation which
includes only contributions of (alpha log(S/m_e^2))^n, the model developed here
contains terms of alpha(alpha log(S/m_e^2))^n, the the next-to-leading
logarithm correction.
The shower model is formulated for the initial radiation in the e^+e^-
annihilation. The generator based on it gives us events with q^2, which is a
virtual mass squared of the virtual photon and/or Z-boson, in accuracy of
0.04%, except for small q^2/S.Comment: 35 pages, 1 figure(eps-file
Efficient Method for Quantum Number Projection and Its Application to Tetrahedral Nuclear States
We have developed an efficient method for quantum number projection from most
general HFB type mean-field states, where all the symmetries like axial
symmetry, number conservation, parity and time-reversal invariance are broken.
Applying the method, we have microscopically calculated, for the first time,
the energy spectra based on the exotic tetrahedral deformation in
Zr. The nice low-lying rotational spectra, which have all
characteristic features of the molecular tetrahedral rotor, are obtained for
large tetrahedral deformation, \alpha_{32} \gtsim 0.25, while the spectra are
of transitional nature between vibrational and rotational with rather high
excitation energies for Comment: Trivial mistakes are correcte
Estratégia complementar para conservação de espécies florestais nativas: resgate e conservação de ecótipos ameaçados.
A devastação das florestas brasileiras vem tomando proporções alarmantes em todos os biomas, colocando muitas espécies de microorganismos, animais e plantas sob risco de extinção devido à descaracterização do habitat. Medidas governamentais contra esse processo de destruição incluem o estabelecimento de unidades de conservação e os programas de plantio de espécies nativas com objetivos variados, como a recuperação de ecossistemas degradados e o estabelecimento de reservas legais, áreas de proteção permanente e outros. As unidades de conservação são fundamentais na conservação de ecossistemas naturais. No entanto, na conservação da variabilidade ecotípica de espécies florestais, sua eficácia se restringe aos limites físicos da sua área de influência. Considerando que a maior parte dos ecótipos florestais de grande significado adaptativo localiza-se fora das unidades de conservação, medidas complementares são indispensáveis, preferencialmente, com a participação de produtores rurais, sobretudo os de pequena escala, por estarem presentes em todo o território nacional. A estratégia proposta tem como ponto fundamental evitar o plantio de sementes ou mudas em locais distantes de suas origens, visando preservar as características adaptativas próprias de cada ecossistema. Para isso, recomendam-se procedimentos para a amostragem de matrizes e instalação de povoamentos florestais para conservação mediante uso pelos produtores rurais
Pesquisa e desenvolvimento florestal em Moçambique.
bitstream/CNPF-2009-09/40965/1/doc131.pd
Espécies não tradicionais para plantios com finalidades produtivas e ambientais: silvicultura e usos.
Seminário realizado em Curitiba, de 6 a 8 de outubro de 1998
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