Evidence for resonant structure near 1780 MeV in e+ e− annihilations observed with the new colliding beam ring at Orsay

We present evidence for the existence of a new J^PC = 1^?? resonance with a mass of 1778 ± 14 (±12) MeV and 150 ± 40 (±30) MeV wide. We tentatively conclude that it is an I = 0 state.     

Sur la structure des algèbres de Kac,I

We elaborate on the relative situation of a Kac algebra and its dual, then, introducing three invariants we obtain a generalization of Heisenberg's commutation relations. Using the operator-valued weights introduced by U. Haagerup, we give a simpler definition for Kac algebras. As an application, we generalize the unicity of the left Haar measure on a locally compact group.     

Hadronic cross sections study in e+e− collisions from 1.350 GeV to 2.125 GeV

The results of the first experiment performed at DCI in e⁺e^? annihilations in the c.m. energy range 1.350–2.125 GeV region are presented. The cross sections of various multipion channels are extracted. Significant structure appears in some specific channels. A relatively narrow resonance around 1.660 GeV decaying into 3π's is found. Charged and neutral multiplicities, and also the ratio R are given.     

The characterization and thermal stability of a cluster grafted on silica surface

Ru₃(CO)₁₂, supported on silica in the absence of oxygen, reacts with silanol groups of the surface to produce a grafted cluster

, which has been characterized by IR and Raman spectroscopy; the molecular formula of this cluster is in agreement with the stoichiometric balance of CO evolved during its formation from Ru₃(CO)₁₂. The grafted cluster is an intermediate step to produce by thermal decomposition small metallic ruthenium particles of 14 Å together with some Ru(II) carbonyl species encapsulated in the silica surface.     

RCM of tripeptide dienes containing a chiral vinylcyclopropane moiety: impact of different Ru-based catalysts on the stereochemical integrity of the macrocyclic products

[structures: see text] Tripeptide dienes containing an (1R,2S)-vinyl aminocyclopropylcarboxylate residue were cyclized to beta-strand scaffolds under ring-closing metathesis (RCM). Conformational factors, ligand effects, and reaction conditions were evaluated. A protocol was developed for the efficient synthesis of 15-membered ring peptides in high diastereomeric purity. These peptides are key synthetic precursors to antiviral agents that target the hepatitis C virus and represent the first class of clinically validated pharmaceutical agents that are synthesized in large scale using RCM.