Two-loop calculation of the effective potential for the Wess-Zumino model

The effective potential for the supersymmetric Wess-Zumino model is computed off-shell to two loops. A renormalization procedure which preserves positivity of the kinetic terms in the effective action is implemented. Supersymmetry is not broken to this order.     

Champs electriques statiques induits par une onde lumineuse dans les milieux ionises

Inside an optical beam of finite radial extension charged particles are acted upon by forces proportional to the gradient of the electromagnetic energy density of the light. They induce quasi-static distributions of charges and fields whose orders of magnitude we derive. These static fields can contribute to non-linear optical processes.     

Algorithme de Neumann–Dirichlet pour des problèmes de contact unilatéral : Résultat de convergenceNeumann–Dirichlet algorithm for unilateral contact problems: Convergence results

In this Note, we propose and we prove the convergence of a Neumann–Dirichlet algorithm in order to approximate a Signorini problem between two elastic bodies. The idea is to retain the natural interface between the two bodies as numerical interface for the domain decomposition and to replace the Dirichlet problem in [4] by a variational inequality. To cite this article: G. Bayada et al., C. R. Acad. Sci. Paris, Ser. I 335 (2002) 381–386.     

Extensive high-resolution study of the crowded rovibrational CH3F spectrum around 3000 cm−1

The infrared spectrum of CH₃F has been remeasured from 2800 to 3160 cm^?1 with a Fourier spectrometer at a resolution of 0.005 cm^?1. By a systematic use of ground-state combination differences, we have assigned 5200 transitions, including several hundred “forbidden” transitions. They can be distributed into seven vibrational bands, which are mixtures of ν₄, ν₁, 2ν₅², 2ν₅⁰, ν₂ + ν₅, 2ν₂, and 3ν₃. More than 20 local resonances have been detected as well as 11 subbands with A₁A₂ splittings. We have attempted to fit all these data in a global model of the “limited-matrix” type including the 6 × 6 resonance due to ζ₂₅^ν, two Fermitype resonances linking ν₁ with 2ν₅⁰ and 2ν₂, respectively, a Coriolis resonance between ν₄ and 2ν₅², and other minor interactions. We conclude that the use of an “infinite-chain” program is unavoidable. We have also identified 80 transitions as belonging to the ν₄ band of ¹³CH₃F occurring in natural abundance.     

The crossing number of the complement of a circuit

Upper and lower bounds for the crossing number of the graph formed by deletion of a hamilton circuit from the complete graph on n vertices are obtained, with exact values for n≤10 and for the rectilinear crossing number for n≤9.     

Heteroatomic chains and their products of cyclisation. IV. t-butyl-2-phthalimido-2-(3,6-dihydro-1,3-2H-thiazine-2-yliden)-acetates substituted in position 5 by a functional group

Substituted N′-thioacetylformamidines, readily enthiolized, exist in fact in the form of zwitterions 8 with the transfer of the mobile hydrogen on the nitrogen N′. These zwitterions under (4 + 2) cyclocondensation with dienophiles. The dihydrothiazines formed ( 10 ) are possible interesting intermediates in the synthesis of cephems and cephalosporin analogs.     

Insights into the Reaction Mechanism of Ethanol Conversion into Hydrocarbons on H‐ZSM‐5

Ethanol dehydration to ethene is mechanistically decoupled from the production of higher hydrocarbons due to complete surface coverage by adsorbed ethanol and diethyl ether (DEE). The production of C₃₊ hydrocarbons was found to be unaffected by water present in the reaction mixture. Three routes for the production of C₃₊ hydrocarbons are identified: the dimerization of ethene to butene and two routes involving two different types of surface species categorized as aliphatic and aromatic. Evidence for the different types of species involved in the production of higher hydrocarbons is obtained via isotopic labeling, continuous flow and transient experiments complemented by UV/Vis characterization of the catalyst and ab initio microkinetic modeling.