Two-particle rapidity correlations in 205 GeV/c pp interactions

Using data obtained from an exposure of the 30-inch bubble chamber at NAL, inclusive and semi-inclusive two-particle rapidity correlations are analyzed for charged-charged, ??, ++, and ± particles. For the inclusive sample, positive correlations are observed in the central region. In the semi-inclusive case, the four-and six-prong events exhibit strong positive correlations near 90° CM. Selection of four-prong events with a large rapidity gap shows that the strong correlation seems to be associated with diffractive-type events.     

High-spin states in 90Nb

The high-spin states in ⁹⁰Nb have been studied by in-beam γ-ray spectroscopy using the 35 MeV ⁸⁹Y(α, 3nγ)⁹⁰Nb and 33 MeV ⁹⁰Zr(³He, p2nγ)⁹⁰Nb reactions. A new isomeric state with half-life 0.44±0.02 σs and J^π = 11^? has been located in this nucleus. The level scheme derived from these measurements is compared with shell-model calculations.     

Overcrowded molecules. V. 3,10-dimethyl-1,12-bis(2-pyridyl)benzo[c] phenanthrene-2,11-diol

The bis ketene acetal adduct of 4a,10a-diazoniaanthra[1,2-α]anthracene diperchlorate ( 10 ) was used to prepare the highly overcrowded benzo[c]phenanthrene 2 by a known procedure. Its oxidation with cupric chloride provided the isoxazolium zwitterion, 3 , via an intramolecular cyclization.     

Borate complexes of benzohydroxamic acid and some of its derivatives

Ultraviolet spectrophotometric measurements in dilute aqueous solution give pK(a) values of 8.78, 8.27, 8.96 and 8.68, respectively, for benzohydroxamic, N-phenylbenzohydroxamic, p-methoxybenzohydroxamic and N-methyl-p-methoxybenzohydroxamic acids. The acids carrying no substituent on nitrogen form 1:1 complexes with boric acid according to the general equation RCONHOH + H(3)BO(3) --> (1:1 complex)(-) + H(+). Equilibrium constants (log K) were found to be -5.70 for benzohydroxamic acid and -5.8 for p-methoxybenzohydroxamic acid. The complexes behave as very weak monoprotic acids and decompose at high pH to yield borate ions and the corresponding hydroxamate ions. The N-substituted hydroxamic acids showed no reaction with boric acid under the same conditions.     

Correlations of high transverse momentum π0 pairs produced at the CERN ISR

Correlations of two π⁰ mesons with transverse momenta up to 10 GeV/c have been measured utilizing apparatus with large azimuthal acceptance. The data are analysed in the context of constituent scattering models, and also compared with a simple “back-ground” hypothesis.     

Results from a search for light-mass dark matter with a p-type point contact germanium detector

We report on several features in the energy spectrum from an ultralow-noise germanium detector operated deep underground. By implementing a new technique able to reject surface events, a number of cosmogenic peaks can be observed for the first time. We discuss an irreducible excess of bulklike events below 3 keV in ionization energy. These could be caused by unknown backgrounds, but also dark matter interactions consistent with DAMA/LIBRA. It is not yet possible to determine their origin. Improved constraints are placed on a cosmological origin for the DAMA/LIBRA effect.     

Decay pathways and entry-state population in (α, xnγ) and (3He, xnγ) reactions on 150Nd

Exclusive neutron spectra and angular distributions have been measured by n-γ coincidence techniques for $\text{(α, x}\text{n}\text{γ)}\text{and}\text{(}{}^3\text{He}\text{, x}\text{n}\text{γ)}$ reactions on ¹⁵⁰Nd in the 25–44 MeV range. The results show that pre-equilibrium processes dominate low-energy light-ion induced reactions at certain beam energies. Analysis of the yrast γ-ray cascades in the residual nuclei shows that a well-defined minimum entry-state spin exists in final nuclei populated by pre-equilibrium processes. This in turn implies the existence of a minimum classical impact parameter for these reactions. These results are discussed in terms of phenomenological models of the reaction mechanisms.     

One-pot tandem decarboxylative allylation-Heck cyclization of allyl diphenylglycinate imines: rapid access to polyfunctionalized 1-aminoindanes

1-Aminoindanes are generated from allyl diphenylglycinate imines employing a "one-pot" palladium-catalyzed decarboxylative allylation-Heck cyclization cascade. Variation of both the aryl and allyl moieties leads to a diverse range of polycyclic imines, amenable to the synthesis of natural products and other biologically relevant small molecules.     

Measurement of the eta-meson mass using psi(2S) --> etaJ/psi

We measure the mass of the eta meson using psi(2S) --> etaJ/psi events acquired with the CLEO-c detector operating at the CESR e(+)e(-) collider. Using the four decay modes eta --> gamma gamma, 3pi(0), pi(+)pi(-)pi(0), and pi(+)pi(-)gamma, we find M(eta) = 547.785 +/- 0.017 +/- 0.057 MeV, in which the first uncertainty is statistical and the second systematic. This result has an uncertainty comparable to the two most precise previous measurements and is consistent with that of NA48, but is inconsistent at the level of 6.5 sigma with the much smaller mass obtained by GEM.