Finite Grand Unified Theories and the Quark Mixing Matrix

In N = 1 super Yang-Mills theories, under certain conditions satisfied by the spectrum and the Yukawa couplings, the beta functions will vanish to all orders in perturbation theory. We address the generation of realistic quark mixing angles and masses in such finite Grand Unified Theories. Working in the context of finite SUSY SU(5), we present several examples with realistic quark mixing matrices. Non-Abelian discrete symmetries are found to be important in satisfying the conditions for finiteness. Our realistic examples are based on permutation symmetries and the tetrahedral symmetry $A_4$. These examples enable us to address questions such as the decay rate of the proton in finite GUTs.Comment: 16 pages, LaTeX, typos correcte

Limits on different Majoron decay modes of 100^{100}Mo and 82^{82}Se for neutrinoless double beta decays in the NEMO-3 experiment

The NEMO-3 tracking detector is located in the Fr\'ejus Underground Laboratory. It was designed to study double beta decay in a number of different isotopes. Presented here are the experimental half-life limits on the double beta decay process for the isotopes $^{100}$Mo and $^{82}$Se for different Majoron emission modes and limits on the effective neutrino-Majoron coupling constants. In particular, new limits on "ordinary" Majoron (spectral index 1) decay of $^{100}$Mo ($T_{1/2} > 2.7\cdot10^{22}$ y) and $^{82}$Se ($T_{1/2} > 1.5\cdot10^{22}$ y) have been obtained. Corresponding bounds on the Majoron-neutrino coupling constant are $< (0.4-1.9) \cdot 10^{-4}$ and $< (0.66-1.7) \cdot 10^{-4}$.Comment: 23 pages includind 4 figures, to be published in Nuclear Physics

Entry mode deviation: a behavioral approach to internalization theory

We explore when and why decision makers choose international entry modes (e.g., hierarchies or markets) that deviate from internalization theory’s predictions. By applying a cognitive perspective on entry mode decision making, we propose that the performance of prior international activities influences decision makers’ behavior in different ways than assumed in internalization theory. More specifically, due to a representativeness bias, underperforming (overperforming) past ventures influence the decision to change (continue using) the previous entry mode choice, which may result in an entry mode deviation. In addition, the propensity to deviate from theoretical predictions is stronger when the experience is recent and/or salient due to an availability bias. In conclusion, we argue that internalization theory can benefit from incorporating more systematically important behavioral assumptions on how firms enter international markets. In so doing, we contribute to the recent conversation on how variations in human behavior influence internalization theory

Efficacy of hip resurfacing arthroplasty: 6 year results from an international multisurgeon prospective cohort study.

Metal-on-metal hip resurfacing is undertaken worldwide. This procedure helps preserve femoral bone stock and allows patients to return to high activity sports. Most outcome studies are individual surgeon case series from single centers where the results and outcomes are evaluated by the same surgeon. One method of increasing the external validity of a follow-up study is to have a multi-centre study design with independent assessment of the outcomes. We present an independent assessment of eleven year follow-up of hip resurfacing outcomes from an international hip resurfacing register. The purpose of this study was to assess: Implant survival at maximum follow-up for revision due to any reason, implant survival at maximum follow-up for revision due to major causes of failure, hip function following hip resurfacing and factors affecting hip function, effect of gender and age on hip function and implant survival, effect of femoral component size on hip function and implant survival. 4535 patients (5000 hips) entered into the registry during 1997-2002 were studied. In summary, at a maximum follow-up of 11 years hip resurfacing has a good implant survival of 96.2% and excellent post-operative function. This is excellent given the international and multisurgeon nature of this cohort where majority of the surgeons were in their learning curve