The neutral kaon system is a sensitive probe of quantum mechanics. We revive a parametrization of non-quantum-mechanical effects that is motivated by considerations of the nature of space-time foam, and show how it can be constrained by new measurements of KL → 2π and KL,S semileptonic decays at LEAR or a φ factory. CERN-TH.6596/92 ACT-18/92 CTP-TAMU-59/92 July 1992 † Permanent address: Center ...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

The oxy-myoglobin (Mb-O2) structure was probed by QM/MM (hybrid quantum mechanical/ molecular mechanical) calculations using DFT/MM to elucidate the effect of the heme propionates and the protein matrix on the chemistry of heme Fe-O2 moiety. On this line, we have probed the role of His97 in various protonation states of the heme propionate-6.

Michael M. Kash,1,5 Vladimir A. Sautenkov,1 Alexander S. Zibrov,1,3 L. Hollberg,3 George R. Welch,1 Mikhail D. Lukin,4 Yuri Rostovtsev,1 Edward S. Fry,1,2 and Marlan O. Scully1,2 1Department of Physics, Texas A&M University, College Station, Texas 77843-4242 2Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany 3National Institute for Standards and Technology, Boulder, Colorado 80303...

H. Bombin, Ruben S. Andrist, Masayuki Ohzeki, Helmut G. Katzgraber, and M.A. Martin-Delgado Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada Theoretische Physik, ETH Zurich, CH-8093 Zurich, Switzerland Department of Systems Science, Graduate School of Informatics, Kyoto University, Yoshida-Honmachi, Sakyo-ku, Kyoto 606-8501, Japan Dipartimento di Fisica, Università...

Spectral properties of sign symmetric matrices are studied. A criterion for sign symmetry of shifted basic circulant permutation matrices is proven, and is then used to answer the question which complex numbers can serve as eigenvalues of sign symmetric 3 × 3 matrices. The results are applied in the discussion of the eigenvalues of QM -matrices. In particular, it is shown that for every positiv...

We consider classes of models related to those introduced by Lehmann in 1953 and Sklar in 1959. Recently developed algorithms for finding profile NP likelihood procedures are discussed, extended and implemented for such models by combining them with the MM algorithm. In particular we consider statistical procedures for a regression model with proportional expected hazard rates, and for transfor...

Gravity models are widely used to explain patterns of trade. However, two stylized features of trade data, sample selection and heteroskedasticity, challenge the estimation of gravity models. We propose a Two-Step Method of Moments (TS-MM) estimator that deals with both issues. The Monte-Carlo experiments show that the TS-MM estimates are resistant to various combinations of sample selection an...