Inverse Cotton-Mouton effect of the Vacuum and of atomic systems

In this letter we calculate the Inverse Cotton-Mouton Effect (ICME) for the vacuum following the predictions of Quantum ElectroDynamics. We compare the value of this effect for the vacuum with the one expected for atomic systems. We finally show that ICME could be measured for the first time for noble gases using state-of-the-art laser systems and for the quantum vacuum with near-future laser facilities like ELI and HiPER, providing in particular a test of the nonlinear behaviour of quantum vacuum at intensities below the Schwinger limit of 4.5x10^33 W/m^2.Comment: Submitted to EP

No light shining through a wall : new results from a photoregeneration experiment

Recently, axion-like particle search has received renewed interest. In particular, several groups have started ``light shining through a wall'' experiments based on magnetic field and laser both continuous, which is very demanding in terms of detector background. We present here the 2$\sigma$ limits obtained so far with our novel set-up consisting of a pulsed magnetic field and a pulsed laser. In particular, we have found that the axion-like particle two photons inverse coupling constant $M$ is $> 8\times 10^5$ GeV provided that the particle mass $m_\mathrm{a} \sim$ 1 meV. Our results definitively invalidate the axion interpretation of the original PVLAS optical measurements with a confidence level greater than 99.9%.Comment: Version that will appear in Physical Review Letters, Vol. 99, n. 18, (2 Nov 2007

Observation of the Inverse Cotton-Mouton Effect

We report the observation of the Inverse Cotton-Mouton Effect (ICME) i.e. a magnetization induced in a medium by non resonant linearly polarized light propagating in the presence of a transverse magnetic field. We present a detailed study of the ICME in a TGG crystal showing the dependence of the measured effect on the light intensity, the optical polarization, and on the external magnetic field. We derive a relation between the Cotton-Mouton and Inverse Cotton-Mouton effects that is roughly in agreement with existing experimental data. Our results open the way to applications of the ICME in optical devices

The BMV project: Search for photon oscillations into massive particles

In this contribution to PSAS08 we report on the research activities developed in our Toulouse group, in the framework of the BMV project, concerning the search for photon oscillations into massive particles, such as axion-like particles in the presence of a strong transverse magnetic field. We recall our main result obtained in collaboration with LULI at \'Ecole Polytechnique (Palaiseau, France). We also present the very preliminary results obtained with the BMV experiment which is set up at LNCMP (Toulouse, France).Comment: Proceedings of PSAS'08, to be published in Can. J. Phy

Extended axion electrodynamics: Optical activity induced by nonstationary dark matter

We establish a new self-consistent Einstein-Maxwell-axion model based on the Lagrangian, which is linear in the pseudoscalar (axion) field and its four-gradient and includes the four-vector of macroscopic velocity of the axion system as a whole. We consider extended equations of the axion electrodynamics, modified gravity field equations, and discuss nonstationary effects in the phenomenon of optical activity induced by axions.Comment: 6 pages, 0 figures, accepted for publication in the Journal Gravitation and Cosmology, reported at the 14th Russian Gravitational Conference (Ulyanovsk, 2011

Birefringence of interferential mirrors at normal incidence Experimental and computational study

In this paper we present a review of the existing data on interferential mirror birefringence. We also report new measurements of two sets of mirrors that confirm that mirror phase retardation per reflection decreases when mirror reflectivity increases. We finally developed a computational code to calculate the expected phase retardation per reflection as a function of the total number of layers constituting the mirror. Different cases have been studied and we have compared computational results with the trend of the experimental data. Our study indicates that the origin of the mirror intrinsic birefringence can be ascribed to the reflecting layers close to the substrate.Comment: To be published in Applied Physics

Porotaxia em larva de carrapatos do gênero Amblyomma como caracterísiticas morfológicas adicionais para a identificação dos estágios imaturos.

Variabilidade intraespecífica e interespecífica das estruturas tegumentares sobre o idiossoma.bitstream/CPAF-RO-2009-09/12171/1/bpd45_porotaxia-em-larvas-de-carrapatos.pd

Current status of ticks and tick-host relationship in domestic and wild animals from Pantanal wetlands in the state of Mato Grosso do Sul, Brazil.

This is a commented list of tick?s species collected on various wild and domestic animals, including the reports on scientifi c literature for the studied region. Most of animals were small or medium mammals. Carnivores were the main taxa group examined. Although, the pampas deer (Ozotocerus bezoarticus) and giant anteater (Mymercophaga tridactyla) also has a good representation on study. Among domestic animals, dogs, horses and cattle were examined. Summing up, 18 tick species were listed for the region. Sixteen were hard ticks (Ixodidae) and two soft ticks (Argasidae). Amblyomma sculptum was the most common and abundant hard tick. Ornithodoros rostratus (Argasidae) was very abundant, being the more important Argasidae tick on the study region. The following species were colleted or reported on scientifi c literature: Argas miniatus Koch, 1844; Ornithodoros rostratus Aragão, 1911; Dermacentor nitens Newmann, 1897; Rhipicephalus (Boophilus) microplus Canestrini, 1887; Amblyomma tigrinum Koch, 1844; A.dissimile Koch, 1844; A. ovale Koch, 1844; A. pauvum Aragão, 1908; A. sculptum Berlese, 1888; A. calcaratum Neumann, 1899; A. coelebs Neumann, 1899; A. dubittatum Newmann, 1899; A. scalpturatum Newmann, 1906; A. naponense Packard, 1869; A. nodosum Newmann, 1899; A. pseudoconcolor Aragão, 1908; A. rotundatum Koch, 1844; A. triste Koch, 1844.Título em português: Estado atual dos carrapatos em relação a seus animais-hospedeiros domésticos e selvagens do Pantanal no Estado do Mato Grosso do Sul, Brasil

Metodologia para o estudo da porotaxia em larvas de carrapatos Ixodidae.

A determinação específica do estágio larval dos ixodídeos tem sido um imenso problema para a sistemática nos últimos anos. Este trabalho visa a elaboração de uma metodologia de descrição de nomenclatura para as larvas de Ixodidae.bitstream/item/24724/1/cot321-carrapato.pd

Particle Dark Matter Candidates

I give a short overview on some of the favorite particle Cold Dark Matter candidates today, focusing on those having detectable interactions: the axion, the KK-photon in Universal Extra Dimensions, the heavy photon in Little Higgs and the neutralino in Supersymmetry. The neutralino is still the most popular, and today is available in different flavours: SUGRA, nuSUGRA, sub-GUT, Mirage mediation, NMSSM, effective MSSM, scenarios with CP violation. Some of these scenarios are already at the level of present sensitivities for direct DM searches.Comment: 7 pages, 4 figures, 3 references added. Contribution to the proceedings of the TAUP 07 conference, Sep. 11-15, Sendai, Japa