Production of MSSM Higgs Bosons in γγ\gamma\gamma Collisions

The heavy Higgs bosons $H,A$ of the minimal supersymmetric extension of the Standard Model can be produced as resonances in high-energy $\gamma\gamma$ colliders. Prospects of the search for these particles in $b\bar b$ and neutralino-pair final states are studied in this report. Heavy Higgs bosons can be found with masses up to about 70-80% of the initial $e^+e^-$ collider energy for moderate values of $\tan\beta$, i.e. in areas of the parameter space not accessible at other colliders.Comment: Contributed to International Workshop on High-Energy Photon Colliders, Hamburg, Germany, 14-17 Jun 2000; 6 pages, latex, 4 figure

Final State Interactions in Hypernuclear Decay

We present an update of the One-Meson-Exchange (OME) results for the weak decay of s- and p-shell hypernuclei (Ref. Phys. Rev. C {\bf 56}, 339 (1997)), paying special attention to the role played by final state interactions between the emitted nucleons. The present study also corrects for a mistake in the inclusion of the $K$ and $K^*$ exchange mechanisms, which substantially increases the ratio of neutron-induced to proton-induced transitions, $\Gamma_n/\Gamma_p$. With the most up-to-date model ingredients, we find that the OME approach is able to describe very satisfactorily most of the measured observables, including the ratio $\Gamma_n/\Gamma_p$.Comment: 20 pages, 2 eps figure

Measurement of SUSY masses via cascade decays for SPS 1a

If R-parity conserving supersymmetry exists below the TeV-scale, new particles will be produced and decay in cascades at the LHC. The lightest supersymmetric particle will escape the detectors, thereby complicating the full reconstruction of the decay chains. In this paper we expand on existing methods for determining the masses of the particles in the cascade from endpoints of kinematical distributions. We perform scans in the mSUGRA parameter space to delimit the region where this method is applicable. From the examination of theoretical distributions for a wide selection of mass scenarios it is found that caution must be exerted when equating the theoretical endpoints with the experimentally obtainable ones. We provide analytic formulae for the masses in terms of the endpoints most readily available. Complications due to the composite nature of the endpoint expressions are discussed in relation to the detailed analysis of two points on the SPS 1a line. Finally we demonstrate how a Linear Collider measurement can improve dramatically on the precision of the masses obtained

Production of MSSM Higgs Bosons in Photon-Photon Collisions

The heavy neutral Higgs bosons H, A in the minimal supersymmetric extension of the Standard Model can be produced as single resonances at high-energy gamma gamma colliders. We have studied the prospects of the search for these particles in b\bar b and neutralino-pair final states. The Higgs bosons can be found with masses up to 70-80% of the initial e^\pm e^- collider energy for medium values of tan(beta), i.e. in areas of the supersymmetric parameter space not accessible at other colliders.Comment: 9 pages, latex, 3 figure

Biochemical parameters of silver catfish (Rhamdia quelen) after transport with eugenol or essential oil of Lippia alba added to the water

The transport of live fish is a routine practice in aquaculture and constitutes a considerable source of stress to the animals. The addition of anesthetic to the water used for fish transport can prevent or mitigate the deleterious effects of transport stress. This study investigated the effects of the addition of eugenol (EUG) (1.5 or 3.0 mu L L-1) and essential oil of Lippia alba (EOL) (10 or 20 mu L L-1) on metabolic parameters (glycogen, lactate and total protein levels) in liver and muscle, acetylcholinesterase activity (AChE) in muscle and brain, and the levels of protein carbonyl (PC), thiobarbituric acid reactive substances (TBARS) and nonprotein thiol groups (NPSH) and activity of glutathione-S-transferase in the liver of silver catfish (Rhamdia quelen; Quoy and Gaimard, 1824) transported for four hours in plastic bags (loading density of 169.2 g L-1). The addition of various concentrations of EUG (1.5 or 3.0 mu L L-1) and EOL (10 or 20 mu L L-1) to the transport water is advisable for the transportation of silver catfish, since both concentrations of these substances increased the levels of NPSH antioxidant and decreased the TBARS levels in the liver. In addition, the lower liver levels of glycogen and lactate in these groups and lower AChE activity in the brain (EOL 10 or 20 mu L L-1) compared to the control group indicate that the energetic metabolism and neurotransmission were lower after administration of anesthetics, contributing to the maintenance of homeostasis and sedation status.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Pesquisa e Desenvolvimento Cientifico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); CNPqinfo:eu-repo/semantics/publishedVersio

Complementarity of the CERN Large Hadron Collider and the e+e−e^+e^- International Linear Collider

The next-generation high-energy facilities, the CERN Large Hadron Collider (LHC) and the prospective $e^+e^-$ International Linear Collider (ILC), are expected to unravel new structures of matter and forces from the electroweak scale to the TeV scale. In this report we review the complementary role of LHC and ILC in drawing a comprehensive and high-precision picture of the mechanism breaking the electroweak symmetries and generating mass, and the unification of forces in the frame of supersymmetry.Comment: 14 pages, 17 figures, to be published in "Supersymmetry on the Eve of the LHC", a special volume of European Physical Journal C, Particles and Fields (EPJC) in memory of Julius Wes

Detecting Physics At The Post-GUT And String Scales By Linear Colliders

The ability of linear colliders to test physics at the post-GUT scale is investigated. Using current estimates of measurements available at such accelerators, it is seen that soft breaking masses can be measured with errors of about (1-20)%. Three classes of models in the post-GUT region are examined: models with universal soft breaking masses at the string scale, models with horizontal symmetry, and string models with Calabi-Yau compactifications. In each case, linear colliders would be able to test directly theoretical assumptions made at energies beyond the GUT scale to a good accuracy, distinguish between different models, and measure parameters that are expected to be predictions of string models.Comment: Latex, 21 pages, no figure

Isotopic and spin selectivity of H_2 adsorbed in bundles of carbon nanotubes

Due to its large surface area and strongly attractive potential, a bundle of carbon nanotubes is an ideal substrate material for gas storage. In addition, adsorption in nanotubes can be exploited in order to separate the components of a mixture. In this paper, we investigate the preferential adsorption of D_2 versus H_2(isotope selectivity) and of ortho versus para(spin selectivity) molecules confined in the one-dimensional grooves and interstitial channels of carbon nanotube bundles. We perform selectivity calculations in the low coverage regime, neglecting interactions between adsorbate molecules. We find substantial spin selectivity for a range of temperatures up to 100 K, and even greater isotope selectivity for an extended range of temperatures,up to 300 K. This isotope selectivity is consistent with recent experimental data, which exhibit a large difference between the isosteric heats of D_2 and H_2 adsorbed in these bundles.Comment: Paper submitted to Phys.Rev. B; 17 pages, 2 tables, 6 figure

Mouse Retinal Development: a Dark Horse Model for Systems Biology Research

The developing retina is an excellent model to study cellular fate determination and differentiation in the context of a complex tissue. Over the last decade, many basic principles and key genes that underlie these processes have been experimentally identified. In this review, we construct network models to summarize known gene interactions that underlie determination and fundamentally affect differentiation of each retinal cell type. These networks can act as a scaffold to assemble subsequent discoveries. In addition, these summary networks provide a rational segue to systems biology approaches necessary to understand the many events leading to appropriate cellular determination and differentiation in the developing retina and other complex tissues