Lipase-catalyzed ester formation in organic solvents an easy preparative resolution α-substituted cyclohexanols

The commercial preparation “lipase My” catalyses ester formation from an alcohol and a fatty acid in organic solvents. Preparative resolution of α-substituted cyclohexanols, including menthol, was achieved under these conditions.     

Simultaneous production of K1o (892) and Δ++(1236) in the reaction K+p→K+π+π−p from 4.3 to 5.0 GeV/c

The reaction $\text{K}{}^{\mathrm{+}}\text{d}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892) Δ}{}^{\mathrm{++}}\text{(1236)}\text{n}{}_{\mathrm{s}}$ from a K⁺d experiment with the CERN 2 m bubble chamber at 4.6 GeV/c is compared with the reaction $\text{K}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892)Δ}{}^{\mathrm{++}}\text{(1236)}$ from a K⁺p experiment at the same energy. In addition, predictions of an absorption model, a Regge pole model and a quark model for the production and decay characteristics of the reaction $\text{K}{}^{\mathrm{+}}\text{p}\text{→}\text{K}{}^{\mathrm{1o}}\text{(892)Δ}{}^{\mathrm{++}}\text{(1236)}$ are tested with the combined statistics of the K⁺d experiment and three K⁺p experiments between 4.3 and 5.0 GeV/c.     

Composite vector fields and tumbling gauge theories

In non-abelian gauge theories with a non-real fermion content it is possible that vector channels become more attractive than the most attractive scalar channel. It is speculated that the appearance of a vector condensate may signal the presence of massless composite vector fields which gauge a flavour symmetry of the underlying model, as is suggested by earlier work on non-linear spinor models.     

Energy measurement at the Darmstadt unilac accelerator

The kinetic energy of⁸⁶Kr ions accelerated by UNILAC (GSI-Darmstadt) was measured using the recoil proton technique. A good agreement was found with the energy values obtained by the time-of-flight technique currently used at UNILAC.     

Direct transfer and two-step processes in the 42Ca(α, 3He)43Ca reaction

The ⁴²Ca(α, ³He)⁴³Ca reaction has been studied at 36 MeV incident energy. Angular distributions have been measured from 4° to 42° using a split-pole spectrometer and position sensitive Si detectors, for about 40 levels located up to 6 MeV excitation energy. A local zero-range DWBA analysis has been carried out; l = 3 and 4 assignments are tentatively proposed for levels located above 4 MeV excitation energy, indicating a strong fragmentation of the $\text{1}\text{f}{}_{\mathrm{<mtext>5</mtext><mtext>2</mtext>}}$ strength between 4 and 6 MeV and the location of the main component of the $\text{1}\text{g}{}_{\mathrm{<mtext>9</mtext><mtext>2</mtext>}}$ strength above 6 MeV. A number of weakly excited levels cannot be reproduced by DWBA analysis. Their angular distributions have been compared with the results of coupled-reaction-channel calculations assuming two-step excitation of weak coupling states with a [⁴²Ca¹ ? $\text{f}{}_{\mathrm{<mtext>7</mtext><mtext>2</mtext>}}$ structure. A reasonable agreement has been obtained, confirming that the two-step process cannot be neglected in the analysis of the (α, ³he) reaction.     

Observation of leading particles in pp interactions with large transverse momentum secondaries at the CERN-ISR

Events with a positive particle of large transverse momentum emitted at medium angles have been studied using the split field magnet spectrometer at the CERN-ISR at a c.m. energy of √s = 52.5 GeV. Positive particles with large longitudinal momentum, |x| > 0.5, i.e., leading particles, associated to large p_T events, are analysed.     

Stéroidohétérocycles: Hétérocycles azotés a 5,6 et 7 chainons accolés simultanément aux cycles A et B d'un stéroide par les positions 4,5 et 6

New systems with five, six or seven membered nitrogen hetero-cycles (pyrazole, pyrimidine or diazepine) simultaneously fused to the 4, 5 and 6 positions of the two A and B rings of a cholestane derivative have been prepared.