Nonlinear supersymmetry and goldstino couplings to the MSSM

We briefly review the nonlinear supersymmetry formalisms in the standard realization and superfield methods. We then evaluate the goldstino couplings to the minimal supersymmetric standard model (MSSM) superfields and discuss their phenomenological consequences. These relate to the tree-level Higgs mass and to invisible Higgs- and Z-boson decays. The Higgs mass is increased from its MSSM tree-level value and brought above the LEP2 mass bound for a low scale of supersymmetry breaking √f ∼ 2 TeV to 7 TeV. The invisible decay rates of the Higgs and Z bosons into goldstino and neutralino are computed and shown to bring stronger constraints on f than their decays into goldstino pairs, which are subleading in 1/f.     

Failure modes in vapor-deposited organic led's

A study of the main failure mechanisms in vacuum vapor-deposited organic light-emitting diodes (LED's) is presented. Three degradation modes were identified for a prototype bilayer ITO/TPD/Alq₃/Mg/Ag device: a) formation and growth of black non-emissive spots, b) abrupt ceasing of light emission associated with catastrophic failures caused by electrical shorts, and c) long term wearout associated with the decrease of quantum efficiency and luminance along with an increase in voltage, while the device is stressed under constant current.     

On the spontaneous breaking of chiral symmetry in QCD

We calculate the vacuum polarization functions of the vector and axial current for massless quarks in second-order perturbation theory. We find that, contrary to previous speculations, there is no indication, at this level, of spontaneous breaking of chiral symmetry in QCD.     

Über die Periodenlänge modp einer Klasse rekursiver Folgen

Ohne ZusammenfassungDiese Arbeit entstand im Rahmen eines von der Deutschen Forschungsgemeinschaft geförderten Forschungsvorhabens.     

Using the idea of expanded core for the exact solution of bi-objective multi-dimensional knapsack problems

We propose a methodology for obtaining the exact Pareto set of Bi-Objective Multi-Dimensional Knapsack Problems, exploiting the concept of core expansion. The core concept is effectively used in single objective multi-dimensional knapsack problems and it is based on the “divide and conquer” principle. Namely, instead of solving one problem with n variables we solve several sub-problems with a fraction of n variables (core variables). In the multi-objective case, the general idea is that we start from an approximation of the Pareto set (produced with the Multi-Criteria Branch and Bound algorithm, using also the core concept) and we enrich this approximation iteratively. Every time an approximation is generated, we solve a series of appropriate single objective Integer Programming (IP) problems exploring the criterion space for possibly undiscovered, new Pareto Optimal Solutions (POS). If one or more new POS are found, we appropriately expand the already found cores and solve the new core problems. This process is repeated until no new POS are found from the IP problems. The paper includes an educational example and some experiments.     

UTILIZATION OF TOOLS FOR SUCCESSFUL. TROUBLESHOOTING OF STRUCTURAL PROBLEMS

A structural failure problem was solved using an integrated and iterative program of testing and analysis. The steps taken in solving the problem were: analytical calculations; operational testing; qualifications of analytical results; problem identification; design of corrective action; and confirmatory testing.     

A study of a possible quark-gluon symmetry in QCD

We study the quark-gluon symmetry manifest in a simple relation for the anomalous dimensions of the Wilson, flavour singlet, operators of deep inelastic scattering. We find that, in the supersymmetry preserving dimensional reduction renormalization scheme, the relation is true at the 2nd order of perturbation expansion in the strong coupling constant.