Absorptive corrections to associated production of strange baryon and meson resonances in πp scattering

Absorptive corrections are calculated for the reactionsπ ⁺ p→K ^*+∑⁺(K ^*+ Y ₁ ^*+ ) mediated byK-exchange andπ ⁺p→K⁺ Y ₁ ^*+ withK ^*-exchange. The effect of the finite width of the resonances is included. Numerical results are given for 5 and 8 GeV/c.     

Kanten-kritische graphen mit der zusammenhangszahl 2

A set of vertices of a graph G represents G if each edge of G is incident with at least one vertex of . A graph G is said to be edge-critical if the minimal number of vertices necessary to represent G decreases if any edge of G is omitted. Plummer [5] has given a method to construct an infinite family of edge-critical graphs with connectivity number 2. We use this method to construct a more extensive class of edge-critical graphs with connectivity number 2 and show that all edge-critical graphs with this connectivity number (K₂) can be constructed from smaller edge-critical graphs. Finally we give examples of edge-critical graphs not constructable from smaller ones by this method.     

Syntheses of the chromomycinone side chain from carbohydrate precursors

Appropriate dithiane derivatives of D-threo configuration were prepared starting with D-arabinose and D-galactose, respectively. Their dianions served for nucleophilic additions to model aldehydes, thus comprising syntheses of the complex side chain of chromomycinone. In contrast to former reports a trianion formation of a dithiane-blocked α,β-dihydroxy aldehyde could not be confirmed.     

Subroutinized tape sorting

The drawbacks of large, general tape sorting programs are pointed out, and a sorting subroutine is suggested as a remedy. The fundamental idea is the separation of the logic in tape sorting from the actual manipulation of external tape units by introduction of the concept of an elementary sorting loop. Examples show how common problems in sorting can be solved using the sorting loop concept. A few considerations in the design and implementation of a sorting subroutine are mentioned, and finally a measure of the efficiency of tape sorting methods is proposed.     

Strongly correlated fermions after a quantum quench

Using the adaptive time-dependent density-matrix renormalization group method, we study the time evolution of strongly correlated spinless fermions on a one-dimensional lattice after a sudden change of the interaction strength. For certain parameter values, two different initial states (e.g., metallic and insulating) lead to observables which become indistinguishable after relaxation. We find that the resulting quasistationary state is nonthermal. This result holds for both integrable and nonintegrable variants of the system.     

Eliminating disjunctions by disjunction elimination

Completeness and other forms of Zorn’s Lemma are sometimes invoked for semantic proofs of conservation in relatively elementary mathematical contexts in which the corresponding syntactical conservation would suffice. We now show how a fairly general syntactical conservation theorem that covers plenty of the semantic approaches follows from an utmost versatile criterion for conservation due to Scott.To this end we work with multi-conclusion entailment relations as extending single-conclusion entailment relations. In a nutshell, the additional axioms with disjunctions in positive position can be eliminated by reducing them to the corresponding disjunction elimination rules, which turn out provable in a wealth of mathematical instances. In deduction terms this means to fold up branchings of proof trees by way of properties of the relevant mathematical structures.Applications include syntactical counterparts of the theorems or lemmas known under the names of Artin–Schreier, Krull–Lindenbaum and Szpilrajn, as well as of the spatiality of coherent locales. Related work has been done before on individual instances, e.g. in locale theory, dynamical algebra, formal topology and proof analysis.