φ meson production fromp\bar p collisions at\sqrt s = 1.8 TeV

Fermilab experiment E735 located at the CO intersection region of the $\sqrt s = 1.8$ TeV $p\bar p$ collider analysed over 900 Φ→K ⁺ K ^? events. Measured were the transverse momentum spectrum, the correlation between the average transverse momentum <pt> and the charged particle multiphcityN _c , as well as the probability of Φ production per charged track,N _Φ /N _c , versusN _c . We have also made an estinate of the total inclusive cross section for Φ mesons, $\sigma (p\bar p \to \phi X) = 7.3 \pm 2.2 mb$ .     

Interface formation and a structural phase transition for the spherical model of ferromagnetism

A detailed analysis is reported examining the local magnetic susceptibility (r), in relation to the correlation functionG(R) and correlation length , of a spherical model ferromagnet confined to geometry =L ^{d –d} × ^d ( ^d 2,d>2) under a continuous set oftwisted boundary conditions. The twist parameter in this problem may be interpreted as a measure of the geometry-dependent doping level of interfacial impurities (or antiferromagnetic seams) in theextended system at various temperatures. For _j 0, jd-d, no seams are present except at infinity, whereas if _j = 1/2, impurity saturation occurs. For 0 < _j < 1/2 the physical domain _phys =D ^{d –d} × ^d (D>L), defining the region between seams containing the origin, depends on temperature above a certain threshold (T>T ₀). Below that temperature (T>T ₀), seams are frozen at the same position (DL/2,d-d'=1), revealing a smoothly varying largescale structural phase transition.     

X-ray photoelectron spectroscopic investigation of conducting polymer blends

Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N(+) at 402.0 eV is separated from that of neutral N. The intensity of the N(+) peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N(+) is close to 4 indicating that one BF(-)(4) dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S(+) can not be resolved but again the F/C ratio correlates with the electrical conductivity.     

Acid-catalyzed cyclization of alkoxyacryloylureas to 2,4(1H,3H)pyrimidinediones

1-Phenylthymine and the carbocyclic analog of thymidine were obtained in yields of 84-87% by cyclizing the appropriate 3-methoxy-2-methylacryloylureas in dilute sulfuric acid. High yields of 1-phenylthymine also resulted when the cyclization was carried out in trifluoroacetic acid, in acetic acid containing toluenesulfonic acid (TSA), or by fusion of the urea with a catalytic amount of TSA. In comparison, the typical aqueous-alkali catalyzed cyclizations gave lower yields of the two thymines, and cleavage of the acryloylureas was shown to occur. However, cyclization in concentrated aqueous ammonia produced high yields of both thymine derivatives.