On the complete analytic structure of the massive gravitino propagator in four-dimensional de Sitter space

With the help of the general theory of the Heun equation, this paper completes previous work by the authors and other groups on the explicit representation of the massive gravitino propagator in four-dimensional de Sitter space. As a result of our original contribution, all weight functions which multiply the geometric invariants in the gravitino propagator are expressed through Heun functions, and the resulting plots are displayed and discussed after resorting to a suitable truncation in the series expansion of the Heun function. It turns out that there exist two ranges of values of the independent variable in which the weight functions can be divided into dominant and sub-dominant families.     

Two-loop vertices in quantum field theory: infrared convergent scalar configurations

A comprehensive study is performed of general massive, scalar, two-loop Feynman diagrams with three external legs. Algorithms for their numerical evaluation are introduced and discussed, numerical results are shown for all different topologies and comparisons with analytical results, whenever available, are performed. An internal cross-check, based on alternative procedures, is also applied. The analysis of infrared divergent configurations, as well as the treatment of tensor integrals, will be discussed in two forthcoming papers.     

An Experimental Assessment of Coleman's Linear System of Action for Supporting Policy Negotiations

We report on an experimental assessment of the applicability of Coleman's Linear System of Action (LSA) to policy negotiations. In LSA, policy negotiations are modeled as exchange of control over issues. LSA allows one to compute the equilibrium control distribution for a group of decision makers, based on their distributions of preferences for, and control over, the issues at stake. The LSA theory, however, does not address the process of how the decision makers should exchange control over the issues to arrive at the equilibrium control. We test in an experimental setting partial and full LSA-based support vs. no support, for three different social structures among the decision makers engaging in repeated bilateral negotiation rounds. The results of the laboratory experiment indicate that the level of LSA support affects the negotiation process and the efficiency of reaching the equilibrium, while the influence of the decision makers' social structure is less clear. These results suggest that Coleman's LSA concept can be employed to support policy negotiations in a practical setting.     

Dehydration of β-Hydroxy-α-amino Acid Derivatives With Phenyltriflimide

Conversion of N-protected β-hydroxy-α-amino esters to corresponding didehydroamino esters has been achieved using phenyltriflimide/triethylamine as a mild dehydrating agent. The selective formation of didehydroalanine derivatives from dipeptides containing, beside a serine residue, another β-hydroxy-α-amino acid, is also described.     

Facile and Versatile Route to the Synthesis of Fused 2‐Pyridones: Useful Intermediates for Polycyclic Sytems

The reaction of various heteroaromatic amino nitriles with diethyl malonate under basic conditions is reported. This reaction affords a series of different highly functionalized 2‐pyridone condensed systems, which can be suitable intermediates in the construction of polyheterocyclic structures.     

Organic light‐emitting transistors with voltage‐tunable lit area and full channel illumination

Organic light‐emitting transistors (OLETs) are multifunctional optoelectronic devices that hold great promise for a variety of applications, including flat panel displays, integrated light sources for sensing and optical communication systems. The narrow illumination area within the device channel is considered intrinsic to the device architecture and is a severe technological drawback for all those applications where a controlled, wide and homogeneous emission area is required. Here it is shown that not only the position but also the extension of the emission area is voltage‐tunable, and the entire channel of the transistor can be homogeneously illuminated. The modeling of the exciton distribution within the channel at the different bias conditions coupled to the modeling of the device emission profile highlights that excitons are spread through the entire channel width and across the bulk of the central emission layer of the p‐channel/emitter/n‐channel trilayer active heterostructure.     

Organic-Inorganic Hybrid Spin-Valve: A Novel Approach to Spintronics

The combined use of highly correlated solids opens the possibility to explore new phenomena and to generate new hybrid devices for Spintronics. We have recently demonstrated the spin injection of carriers into an organic semiconductor, sexithienyl (T 6 ). A spin-valve device has been realized by using two colossal magnetoresistance (CMR) half metallic electrodes separated by the organic semiconductor. The total magnetoresistance as large as 30% was detected for channel lengths lower than 140 nm.     

NLO electroweak corrections to Higgs boson production at hadron colliders

Results for the complete NLO electroweak corrections to Standard Model Higgs production via gluon fusion are included in the total cross section for hadronic collisions. Artificially large threshold effects are avoided working in the complex-mass scheme. The numerical impact at LHC (Tevatron) energies is explored for Higgs mass values up to 500 GeV (200 GeV). Assuming a complete factorization of the electroweak corrections, one finds a +5% shift with respect to the NNLO QCD cross section for a Higgs mass of 120 GeV both at the LHC and the Tevatron. Adopting two different factorization schemes for the electroweak effects, an estimate of the corresponding total theoretical uncertainty is computed.