137 research outputs found
Anomaly Mediated Supersymmetry Breaking without R-Parity
We analyze the low energy features of a supersymmetric standard model where
the anomaly--induced contributions to the soft parameters are dominant in a
scenario with bilinear --parity violation. This class of models leads to
mixings between the standard model particles and supersymmetric ones which
change the low energy phenomenology and searches for supersymmetry. In
addition, --parity violation interactions give rise to small neutrino masses
which we show to be consistent with the present observations.Comment: 38 pages, 15 figures. For higher resolution figures go to
http://www.fma.if.usp.br/~magro/figures
Generation of entangled coherent states via cross phase modulation in a double electromagnetically induced transparency regime
The generation of an entangled coherent state is one of the most important
ingredients of quantum information processing using coherent states. Recently,
numerous schemes to achieve this task have been proposed. In order to generate
travelling-wave entangled coherent states, cross phase modulation, optimized by
optical Kerr effect enhancement in a dense medium in an electromagnetically
induced transparency (EIT) regime, seems to be very promising. In this
scenario, we propose a fully quantized model of a double-EIT scheme recently
proposed [D. Petrosyan and G. Kurizki, {\sl Phys. Rev. A} {\bf 65}, 33833
(2002)]: the quantization step is performed adopting a fully Hamiltonian
approach. This allows us to write effective equations of motion for two
interacting quantum fields of light that show how the dynamics of one field
depends on the photon-number operator of the other. The preparation of a
Schr\"odinger cat state, which is a superposition of two distinct coherent
states, is briefly exposed. This is based on non-linear interaction via
double-EIT of two light fields (initially prepared in coherent states) and on a
detection step performed using a beam splitter and two photodetectors.
In order to show the entanglement of a generated entangled coherent state, we
suggest to measure the joint quadrature variance of the field. We show that the
entangled coherent states satisfy the sufficient condition for entanglement
based on quadrature variance measurement. We also show how robust our scheme is
against a low detection efficiency of homodyne detectors.Comment: 15 pages, 9 figures; extensively revised version; added Section
Producing the event ready two photon polarization EPR state with linear optics devices
We propose a scheme to produce the maximally two photon polarization
entangled state(EPR state) with single photon sources and the linear optics
devices. In particular, our scheme requires the photon detectors only to
distinguish the vacuum and non-vacuum Fock number states. A sophisticated
photon detector distinguishing one or two photon states is unnecessary.Comment: Published in Phys. Rev. A alread
Seroprevalence of Toxoplasma gondii infection among indian people living in Iauareté, São Gabriel da Cachoeira, Amazonas, Brazil
Patterns of seizure control in patients with mesial temporal lobe epilepsy with and without hippocampus sclerosis
Parâmetros da fermentação ruminal e concentração de derivados de purina de vacas em lactação alimentadas com castanha de caju
Systematics, taxonomy and floristics of Brazilian Rubiaceae: an overview about the current status and future challenges
Mean field effects on the scattered atoms in condensate collisions
We consider the collision of two Bose Einstein condensates at supersonic
velocities and focus on the halo of scattered atoms. This halo is the most
important feature for experiments and is also an excellent testing ground for
various theoretical approaches. In particular we find that the typical reduced
Bogoliubov description, commonly used, is often not accurate in the region of
parameters where experiments are performed. Surprisingly, besides the halo pair
creation terms, one should take into account the evolving mean field of the
remaining condensate and on-condensate pair creation. We present examples where
the difference is clearly seen, and where the reduced description still holds.Comment: 6 pages, 4 figure
Cardiovascular responses to microinjections of GABA or anesthetics into the rostral ventrolateral medulla of conscious and anesthetized rats
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