Breached pairing superfluidity: possible realization in QCD

We propose a wide universality class of gapless superfluids, and analyze a limit that might be realized in quark matter at intermediate densities. In the breached pairing color superconducting phase heavy s quarks, with a small Fermi surface, pair with light u or d quarks. The ground state has a superfluid and a normal Fermi component simultaneously. We expect a second-order phase transition, as a function of increasing density, from the breached pairing phase to the conventional color-flavor locked phase.     

Relationship between Hawking radiation and gravitational anomalies

We show that in order to avoid a breakdown of general covariance at the quantum level the total flux in each outgoing partial wave of a quantum field in a black hole background must be equal to that of a (1+1)-dimensional blackbody at the Hawking temperature.     

Breached superfluidity via p-wave coupling

Anisotropic pairing between fermion species with different Fermi momenta opens two-dimensional areas of gapless excitations, thus producing a spatially homogeneous state with coexisting superfluid and normal fluids. This breached pairing state is stable and robust for arbitrarily small mismatch and weak p-wave coupling.     

Possible degeneracy of heavy quarks

In an attempt to understand the behavior of the total cross-section in electron-positron annihilation, it is suggested that two types of heavy quarks might exist with masses split only by the weak interactions. Implications and tests of this suggestion are discussed.     

Observability of earth-skimming ultrahigh energy neutrinos

Neutrinos with energies above 10(8) GeV are expected from cosmic ray interactions with the microwave background and are predicted in many speculative models. Such energetic neutrinos are difficult to detect, as they are shadowed by Earth, but rarely interact in the atmosphere. Here we propose a novel detection strategy: Earth-skimming neutrinos convert to charged leptons that escape Earth, and these leptons are detected in ground level fluorescence detectors. With the existing HiRes detector, neutrinos from some proposed sources are marginally detectable, and improvements of 2 orders of magnitude are possible at the proposed Telescope Array.     

Electrophilic substitution of organosilicon compounds. II. Synthesis of allyl-terminated polyisobutylenes by quantitative allylation of tert-chloro-polyisobutylenes with allyltrimethylsilane

Essentially quantitative allylation of linear and three-arm star tert-chloro capped polyisobutylenes [^tCl–PIB–Cl^t and PIB(Cl^t)₃] has been achieved by the use of allyltrimethylsilane (AllylSiMe₃) and Friedel–Crafts acids. Quantitative allylation occurs under suitable conditions, e.g., slight molar excess of TiCl₄ and AllySiMe₃ polar media, ?70°C. These conditions have been developed from quantitative model allylation experiments using 2,4,4-trimethyl-2-chloropentane. Essentially quantitative allylation occurs with long-chain or “once fired” tert-chloro-end groups. Complete allylation can also be effected in a “one-pot two-step” synthesis, i.e., by first preparing the tert-chloro-ended PIB by the inifer method and without isolating the product, completing the synthesis by allylation in the same reactor. Extensive but not quantitative allylation can also be obtained in situ, i. e., during polymerization, by the use of the AllylSiMe₃/cumyl chloride/BCI₃/isobutylene combination. While allylation proceeds with great ease under the mildest conditions, e.g., ?70°C, vinylation with vinyltrimethylsilane could not be achieved even under more forcing conditions.     

C and H nuclear magnetic shielding and spin–spin coupling constants of C-enriched bromomethane in the gas phase

¹³C and ¹H NMR spectral parameters are investigated for ¹³CH₃Br in gaseous matrices. It is found that both the ¹³C and ¹H chemical shifts of ¹³CH₃Br are linearly dependent on solvent density. Similar dependence is also detected for one-bond spin–spin coupling, ¹J(CH). For the first time the ¹³C and ¹H magnetic shielding constants and ¹J(CH) spin–spin coupling are obtained for an isolated ¹³CH₃Br molecule together with the coefficients responsible for solute–solvent molecular interactions in gaseous matrices. The present experimental results confirm the accuracy of some recent ab initio calculations of nuclear magnetic shielding performed for bromomethane.     

Metal body burdens and detoxifying enzymes in spiders from industrially polluted areas

Detoxifying enzymes have been assayed and metal concentrations have been monitored in four species of spiders from differently contaminated localities in Southern Poland. A behavioural feeding activity and the life style decide on sensitivity and vulnerability of spiders. Wolf-spiders, more active than the web-spinners, cumulate higher amounts of metals, reflecting quantitatively and qualitatively the pollution level in their environment. Detoxifying systems in spiders appeared inducible and efficient to maintain normal physiological responses. Within web-spinning spiders the linyphiids seem to be the most effective regulators of metal burdens. Their detoxifying capabilities correlate well with increased industrial contaminants. The analysis of biochemical biomarkers of exposure confirmed earlier ecological findings that species of the family Linyphiidae are more favoured than the Araneidae. Differences in their feeding activity, behaviour of web-spinning and the size of animals would explain alterations in detoxifying abilities between Meta segmentata and Araneus diadematus.