QCD and final-state jet measures in leptoproduction

Various infrared-safe measures of jet-like-ness in leptoproduction are studied in QCD perturbation theory using a general formalism. This quantifies the effects predicted in a previous paper. The nucleon remnants jet is found to be distinctly narrower than the quark jet.     

Organo-nonmetallic chemistry: Pentacoordinate,ten-electron (10-X-5) compounds of silicon,phosphorus and sulfur

Abstract

We have shown that ligands to nonmetals can be designed to stabilize five-coordinate species, relative to four- or six-coordinate ones. Nondissociative permutational isomerization of identically substituted hypervalent 10-Si-5 siliconate anions and neutral 10-P-5 phosphoranes is faster for the isoelectronic isostructural silicon species. Nucleophile mediated stereochemical inversion in silanes which are substituted by ligands which stabilize trigonal bipyramidal species is shown to proceed by pseudorotation of an intermediate 10-Si-5 species.     

Structure and synthesis of hypophyllanthin,nirtetralin, phyltetralin and lintetralin

Structures propounded for the four aryltetralin lignan constituents isolated from $\text{Phyllanthus niruri}$ Linn. are confirmed by syntheses of their (±)-forms.     

Search for ΔQ=−ΔS transitions in Σ-hyperon decays

In a sample of 10⁶ Σ ⁺ hyperons we have searched for the decaysσ ⁺→ ne⁺ ν andσ ⁺→nμ ⁺ ν, which would violate theΔQ=ΔS rule. NoΣ ⁺→ne⁺ ν decay was found, whereas 313σ ^?→ne^? ν decays were identified in the same film. With 90% confidence we obtain $$\frac{{\Gamma (\sum ^ + \to ne^ + v)}}{{\Gamma (\sum ^ - \to ne^ - \bar v)}} \leqq 3.10^{ - 2} .$$ Having found two candidates for the decayσ ⁺→nμ ⁺ ν and 104Σ ^?→nμ ^? ν events we obtain for the muonic mode $$\frac{{\Gamma (\sum ^ + \to ne^ + v)}}{{\Gamma (\sum ^ - \to ne^ - \bar v)}} \leqq 3.10^{ - 2} .$$ The probability that theμ ⁺-events are simulated byσ ⁺→nπ ⁺ γ with subsequent undetectedπ ⁺→μ ⁺ ν decay is less than 4%.     

Gaussian-effective-potential studies of fermion-scalar theories

We study some rather general 1+1 dimensional fermion-scalar models containing fourfermion terms, using the Gaussian-effective-potential (GEP) approach. Model I has a Yukawa \(\left( {\phi \bar \psi \psi } \right)\) coupling, and possesses a continuous chiral symmetry. Model II has a \(\phi ^2 \bar \psi \psi \) coupling, preserving theO(N) symmetry of the scalar sector. For each model two distinct kinds of renormalization are possible: in “case A” the fermion-scalar and four-fermion bare coupling constants may remain finite; in “case B” the bare couplings take on particular infinitesimal forms. For model I, the chiral symmetry is unbroken in case A, but spontaneously broken in case B. There are parallels with GEP studies of (λφ⁴)₄ theory, where two distinct renormalizations (“autonomous” and “precarious”) are also found.     

Triazolines. XXIII. High-performance liquid chromatographic assay in rat blood for a novel triazoline anticonvulsant (ADD17014)

A sensitive and specific high-performance liquid chromatographic (HPLC) method for the analysis of 1-(4-chlorophenyl)-5-(4-pyridyl)-delta 2-1,2,3-triazoline (ADD17014, I), a novel anticonvulsant agent, in rat blood is described. Compound I and the internal standard (dipyridamole) were extracted into diethyl ether (5 ml) from alkalinised blood (0.25 ml of blood plus 0.75 ml of pH 10.7 buffer), with extractability nearing 100% under these conditions. The assay is based on reversed-phase HPLC (25 cm x 0.46 cm I.D. Spherisorb 5-ODS) using a mobile phase of methanol-acetonitrile-McIlvaine's citric acid-phosphate buffer (pH 8.0, 0.005 M) (30:30:40, v/v) and ultraviolet detection at 290 nm. Calibration curves were linear and reproducible (correlation coefficient greater than 0.999). Measurement of I in rat blood (250 microliters sample size) was linear in the range 0-40 microgram/ml and the coefficient of variation was less than 5%. The minimum detectable level was about 0.1 microgram/ml; however, a larger blood sample size (1-2 ml) allowed measurement of levels as low as 10 ng/ml, especially for estimation of drug levels in samples withdrawn at later time points (24 h).