Status of the OPERA Experiment

In this article the physics motivation and the detector design of the OPERA experiment will be reviewed. The construction status of the detector, which will be situated in the CNGS beam from CERN to the Gran Sasso laboratory, will be reported. A survey on the physics performance will be given and the physics plan in 2006 will be presented.Comment: 5 pages, 4 figures, conference proceedings, to be published in Acta Physica polonica

Near-field spectra of quantum well excitons with non-Markovian phonon scattering

The excitonic absorption spectrum for a disordered quantum well in presence of exciton-acoustic phonon interaction is treated beyond the Markov approximation. Realistic disorder exciton states are taken from a microscopic simulation, and the deformation potential interaction is implemented. The exciton Green's function is solved with a self energy in second order Born quality. The calculated spectra differ from a superposition of Lorentzian lineshapes by enhanced inter-peak absorption. This is a manifestation of pure dephasing which should be possible to measure in near-field experiments.Comment: 8 pages, 7 figure

Comment on "Dephasing Times in Quantum Dots due to Elastic LO Phonon-Carrier Collisions"

This paper is a Comment on Phys. Rev. Lett. 85, 1516 (2000) by A.V. Uskov, A.-P. Jauho, B. Tromborg, J. Mork, and R. Lang.Comment: 1 page, 1 figure. Phys. Rev. Lett., accepte

Pseudo-R2 Measures for Some Common Limited Dependent Variable Models

A large number of different Pseudo-R2 measures for some common limited dependent variable models are surveyed. Measures include those based solely on the maximized likelihoods with and without the restriction that slope coefficients are zero, those which require further calculations based on parameter estimates of the coefficients and variances and those that are based solely on whether the qualitative predictions of the model are correct or not. The theme of the survey is that while there is no obvious criterion for choosing which Pseudo-R2 to use, if the estimation is in the context of an underlying latent dependent variable model, a case can be made for basing the choice on the strength of the numerical relationship to the OLS-R2 in the latent dependent variable. As such an OLS-R2 can be known in a Monte Carlo simulation, we summarize Monte Carlo results for some important latent dependent variable models (binary probit, ordinal probit and Tobit) and find that a Pseudo-R2 measure due to McKelvey and Zavoina scores consistently well under our criterion. We also very briefly discuss Pseudo-R2 measures for count data, for duration models and for prediction-realization tables

Dephasing in Quantum Dots: Quadratic Coupling to Acoustic Phonons

A microscopic theory of optical transitions in quantum dots with carrier-phonon interaction is developed. Virtual transitions into higher confined states with acoustic phonon assistance add a quadratic phonon coupling to the standard linear one, thus extending the independent Boson model. Summing infinitely many diagrams in the cumulant, a numerically exact solution for the interband polarization is found. Its full time dependence and the absorption lineshape of the quantum dot are calculated. It is the quadratic interaction which gives rise to a temperature-dependent broadening of the zero-phonon line, being here calculated for the first time in a consistent scheme.Comment: 4 pages, 2 figure