1,637 research outputs found
Feno e silagem como volumoso para confinamento de bovinos de corte.
bitstream/item/67190/1/CT-49-2001.pd
Prospects for single-photon sideband cooling of optically trapped neutral atoms
We propose a cooling scheme for realizing single-photon sideband cooling on particles trapped in a state-dependent optical potential. We develop a master rate equation from an ab initio model and find that in experimentally feasible conditions it is possible to reduce the average occupation number of the vibrational levels in one dimension by more than 90% by applying a frequency sweep on the cooling laser that sequentially cools all the motional states. Notably, this cooling scheme works also when a particle experiences a deeper trap in its internal ground state than in its excited state, a condition for which conventional single-photon sideband cooling does not work. In our analysis, we consider two cases: a two-level particle confined in an optical tweezer, and Li atoms confined in an optical lattice, and we find conditions for efficient cooling in both cases. The results from the model are confirmed by a full quantum Monte Carlo simulation of the system Hamiltonian. Our findings provide an alternative cooling scheme that can be applied in principle to any particle, e.g., atoms, molecules, or ions, confined in a state-dependent optical potential
Monte Carlo studies of the jet activity in Higgs + 2 jet events
Tree-level studies have shown in the past that kinematical correlations
between the two jets in Higgs+2-jet events are direct probes of the Higgs
couplings, e.g. of their CP nature. In this paper we explore the impact of
higher-order corrections on the azimuthal angle correlation of the two leading
jets and on the rapidity distribution of extra jets. Our study includes
matrix-element and shower MC effects, for the two leading sources of Higgs plus
two jet events at the CERN LHC, namely vector-boson and gluon fusion. We show
that the discriminating features present in the previous leading-order matrix
element studies survive.Comment: 12 pages, 10 figures. Version to appear on JHEP. Figs. 5-8 replaced
with colour version
Avaliação de cultivares de trigo de duplo propósito, recomendados para cultivo no estado do Rio Grande do Sul.
bitstream/CNPT-2010/37413/1/Comunicado-137.pd
Some analytic results for two-loop scattering amplitudes
We present analytic results for the finite diagrams contributing to the
two-loop eight-point MHV scattering amplitude of planar N=4 SYM. We use a
recently proposed representation for the integrand of the amplitude in terms of
(momentum) twistors and focus on a restricted kinematics in which the answer
depends only on two independent cross-ratios. The theory of motives can be used
to vastly simplify the results, which can be expressed as simple combinations
of classical polylogarithms.Comment: 18 page
Avaliação de cultivares de trigo de duplo propósito, recomendados para cultivo no estado do Rio Grande do Sul.
bitstream/item/31090/1/Comunicado-137.pd
Resultados da experimentação de genótipos de trigo para aptidão a duplo propósito no Paraná, em 2000.
bitstream/item/84114/1/CNPT-BOL.-PESQ.-6-01.pd
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