Six-fermion production and Higgs boson physics at future e^+ e^- colliders

The six-fermion production processes , with all the lepton flavours and , relevant to the study of the intermediate-mass Higgs boson at future linear colliders are analysed. A Monte Carlo program, taking into account the whole set of tree-level scattering amplitudes and the relevant radiative effects, is developed to provide integrated cross-sections and generation of unweighted events. The complete calculation is compared with the available results of real Higgs production, and the opportunities of precision studies with event generation are discussed, demonstrating the relevance of a full six-fermion calculation. Numerical results for integrated cross-sections with various kinematical cuts and including radiative effects are given and commented. In the analysis of event samples, several distributions are studied and found to be sensitive to the presence and to the properties of the Higgs boson. Received: 20 December 1998 / Published online: 27 April 1999     

Comparison of extracting solutions for elemental fractionation in airborne particulate matter

It is here described the comparison of extraction efficiency of some solutions (acetate buffer, deionized water, diluted HNO₃ and EDTA) frequently adopted in literature for evaluating the elemental solubility in airborne particulate matter. This comparison was performed considering the distribution of As, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Na, Ni, Pb, S, Si, Sb, Sn, Sr, Ti, V, Zn between the extractable and mineralized residual fractions on the NIST 1648 certified material, PM₁₀ real samples and size-segregated samples, collected by a 13-stage impactor.The extracting solutions were evaluated by comparing extractive efficiencies and robustness towards some factors, such as acidity and concentration of complexing species, that have great environmental variability and that could be able to modify the extractive efficiency.Furthermore, extraction methods application to size-segregated samples allowed estimating the selectivity of extracting solutions towards dimensionally characterized emission sources, as dusts originated from abrasion and road dust re-suspension.On the basis of the obtained results, it was possible to define the main advantages and disadvantages resulting from the use of different extracting solutions, necessary to make possible the comparison of environmental studies carried out in different extractive conditions and to start up a proper study for harmonizing extracting procedures.     

Topological Features of Massive Bosons on Two-Dimensional Einstein Space–Time

In this paper, we tackle the problem of constructing explicit examples of topological cocycles of Roberts’ net cohomology, as defined abstractly by Brunetti and Ruzzi. We consider the simple case of massive bosonic quantum field theory on the two-dimensional Einstein cylinder. After deriving some crucial results of the algebraic framework of quantization, we address the problem of the construction of the topological cocycles. All constructed cocycles lead to unitarily equivalent representations of the fundamental group of the circle (seen as a diffeomorphic image of all possible Cauchy surfaces). The construction is carried out using only Cauchy data and related net of local algebras on the circle.     

The anisotropy of inverse beta decay and antineutrino detection

The anisotropy of the positrons emitted in the reaction has to be taken into account for extracting an antineutrino signal in Superkamiokande. For the Sun, this effect allows a sensitivity to transition probability at the 3% level already with the statistics collected in the first hundred days. For a supernova in the Galaxy, the effect is crucial for extracting the correct ratio of events.     

Analysis of natural corticosteroids in adrenal extracts and in biological fluids by high-performance liquid chromatography

A liquid chromatographic procedure is described for the analysis of the principal natural corticosteroids in extracts of adrenal glands. Microparticulate silicic acid columns and gradients of methanol in chloroform are used: conditions are described for the quantitative analysis of the single principal steroidal components of adrenal extracts for pharmaceutical use and of adrenal extracts of rats. In the last case, the use of a 5-micron silica column with the appropriate gradient allows the determination of corticosterone and of 18-hydroxydeoxycorticosterone, which were identified by means of mass spectrometry on their eluates. A single analysis can be performed on the extract of 15 mg of rat adrenal tissue. For the last type of analysis, isocratic conditions on a 10-micron LiChrosorb Diol column are also described. The application of the gradient elution procedure to the analysis of steroidal compounds in human plasma is also described.     

Assignment of FIR Laser Lines of Hydrazine

With 228 known FIR laser emissions, hydrazine is the most prolific laser active molecules after methanol. But, due to the complexity of its rovibrational spectrum, only a few assignments of hydrizine FIR laser transitions are found in literature. Here we analyze 44 FIR laser lines of hydrazine excited by 20 different CO₂ pumps. The pump transitions are compared to available assignments of IR amino-wagging transitions. We propose values for the J and K quantum numbers involved in 41 FIR laser transitions, for 22 of them we give also the symmetry species.     

Cost allocation protocols for supply contract design in network situations

The class of Construct and Charge (CC-) rules for minimum cost spanning tree (mcst) situations is considered. CC-rules are defined starting from the notion of charge systems, which specify particular allocation protocols rooted on the Kruskal algorithm for computing an mcst. These protocols can be easily implemented in practical network situations (for instance, in supply transportation networks), are flexible to changes in the network situation and meet the requirement of continuous monitoring by the agents involved. Special charge systems, that we call conservative, lead to a subclass of CC-rules that coincides with the class of obligation rules for mcst situations. The authors thank two anonymous referees both for detailed remarks and for interesting general comments on a previous version of the paper. Stef Tijs and Rodica Branzei are indebted to Daniel Granot for useful discussions on the topics treated in this paper and his hospitality during our research visit at British Columbia University at Vancouver in July–August 2003.