25,599 research outputs found
Testing SUSY models of lepton flavor violation at a photon collider
The loop level lepton flavor violating signals are studied in a scenario of
low-energy, R-parity conserving, supersymmetric seesaw mechanism within the
context of a high energy photon collider. Lepton flavor violation is due to off
diagonal elements in the left s-lepton mass matrix induced by renormalization
group equations. The average slepton masses and the off
diagonal matrix elements are treated as model independent free
phenomenological parameters in order to discover regions in the parameter space
where the signal cross section may be observable. At the energies of the
option of the future high-energy linear collider the signal has
a potentially large standard model background, and therefore particular
attention is paid to the study of kinematical cuts in order to reduce the
latter at an acceptable level. We find, for the () channel,
non-negligible fractions of the parameter space () where the statistical significance ()
is .Comment: 26 pages, 12 figures, Revtex
Decay of distance autocorrelation and Lyapunov exponents
This work presents numerical evidences that for discrete dynamical systems
with one positive Lyapunov exponent the decay of the distance autocorrelation
is always related to the Lyapunov exponent. Distinct decay laws for the
distance autocorrelation are observed for different systems, namely exponential
decays for the quadratic map, logarithmic for the H\'enon map and power-law for
the conservative standard map. In all these cases the decay exponent is close
to the positive Lyapunov exponent. For hyperbolic conservative systems, the
power-law decay of the distance autocorrelation tends to be guided by the
smallest Lyapunov exponent.Comment: 7 pages, 8 figure
Biomassa microbiana do solo em cultivos de pinhão-manso consorciados com diferentes espécies vegetais.
JIPE 2013
Charmed hadron signals of partonic medium
We present a short review of our results on the collectivity and the
suppression pattern of charmed mesons in heavy-ion collisions based on the
microscopic Hadron-String Dynamics (HSD) transport approach for different
scenarios of charm interactions with the surrounding matter - the 'comover'
dissociation by mesons with further recreation by D+Dbar channels and
'pre-hadronic' interaction scenarios. While at SPS energies the hadronic
'comover' absorption scenario is found to be compatible with the experimental
data, the dynamics of c and cbar quarks at RHIC are dominated by partonic or
'pre-hadronic' interactions in the strongly coupled quark-gluon plasma stage
and cannot be modeled by pure hadronic interactions. We find that the
collective flow of charm in the purely hadronic scenario appears compatible
with the data at SPS energies but underestimates the data at top RHIC energies.
Thus, the large elliptic flow v2 of D mesons and the low R_AA(pT) of J/Psi seen
experimentally at RHIC have to be attributed to early interactions of
non-hadronic degrees of freedom. Simultaneously, we observe that non-hadronic
interactions are mandatory in order to describe the narrowing of the J/Psi
rapidity distribution from p+p to central Au+Au collisions at the top RHIC
energy. We demonstrate additionally that the strong quenching of high-pT
J/Psi's in central Au+Au collisions indicates that a fraction of final J/Psi
mesons is created by a coalescence mechanism close to the phase boundary.Comment: Talk given at International Conference on Strangeness in Quark Matter
(SQM 2008), Beijing, China, 6-10 Oct 200
Cevadilha vacariana (Bromus auleticusTrinius): histórico, utilização e perspectivas.
Histórico e importância; Resultados de pesquisa e considerações gerais; Considerações finais e perspectivas.bitstream/item/64232/1/DT88.pdfTambém publicado na versão impressa
Efeito do aumento da concentração de CO2 do ar sobre a severidade e esporulação de Cylindrocladium scoparium em folhas destacadas de eucalipto.
Resumo: As mudanças climáticas podem ocasionar alterações no ciclo de infecção dos patógenos, no desenvolvimento das plantas e na incidência de doenças. A concentração de CO2 atmosférico vem aumentando significativamente nas últimas décadas e seus efeitos sobre patossistemas ainda são pouco conhecidos. O objetivo deste trabalho foi verificar o efeito de elevadas concentrações de CO2 do ar sobre a severidade de manchas foliares causadas por Cylindrocladium scoparium em folhas destacadas de eucalipto e a esporulação do patógeno. Uma suspensão de conídios de C. scoparium foi inoculada em folhas destacadas de Eucalyptus urophylla e mantidas nas concentrações de CO2: 390 ppm (testemunha), 634±89 ppm, 800±202 ppm e 1122±211 ppm, em sala climatizada, a 27o C por vinte e quatro dias. O aumento da concentração de CO2 não teve efeito sobre a área foliar lesionada e a produção de conídios pelo patógeno
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