Semidirect Product Groups, Vacuum Alignment and Tribimaximal Neutrino Mixing

The neutrino oscillation data are in very good agreement with the tribimaximal mixing pattern: \sin^2\theta_{23}=1/2, \sin^2\theta_{12}=1/3, and \sin^2\theta_{13}=0. Attempts to generate this pattern based on finite family symmetry groups typically assume that the family symmetry is broken to different subgroups in the charged lepton and the neutrino mass matrices. This leads to a technical problem, where the cross-couplings between the Higgs fields responsible for the two symmetry breaking chains force their vacuum expectation values to align, upsetting the desired breaking pattern. Here, we present a class of models based on the semidirect product group (S_3)^4 \rtimes A_4, where the lepton families belong to representations which are not faithful. In effect, the Higgs sector knows about the full symmetry while the lepton sector knows only about the A_4 factor group. This can solve the alignment problem without altering the desired properties of the family symmetry. Inclusion of quarks into the framework is straightforward, and leads to small and arbitrary CKM mixing angles. Supersymmetry is not essential for our proposal, but the model presented is easily supersymmetrized, in which case the same family symmetry solves the SUSY flavor problem.Comment: Typos fixed, 26 pages in LaTe

Anderson localization of pairs in bichromatic optical lattices

We investigate the formation of bound states made of two interacting atoms moving in a one dimensional (1D) quasi-periodic optical lattice. We derive the quantum phase diagram for Anderson localization of both attractively and repulsively bound pairs. We calculate the pair binding energy and show analytically that its behavior as a function of the interaction strength depends crucially on the nature -extended, multi-fractal, localized- of the single-particle atomic states. Experimental implications of our results are discussed.Comment: final revised version with more explanations, 4 pages, 3 figure

Peaks and Troughs in Helioseismology: The Power Spectrum of Solar Oscillations

I present a matched-wave asymptotic analysis of the driving of solar oscillations by a general localised source. The analysis provides a simple mathematical description of the asymmetric peaks in the power spectrum in terms of the relative locations of eigenmodes and troughs in the spectral response. It is suggested that the difference in measured phase function between the modes and the troughs in the spectrum will provide a key diagnostic of the source of the oscillations. I also suggest a form for the asymmetric line profiles to be used in the fitting of solar power spectra. Finally I present a comparison between the numerical and asymptotic descriptions of the oscillations. The numerical results bear out the qualitative features suggested by the asymptotic analysis but suggest that numerical calculations of the locations of the troughs will be necessary for a quantitative comparison with the observations.Comment: 18 pages + 8 separate figures. To appear in Ap

An Analysis of Theme and Rheme Used in the Five-star Hotels' Web Sites in Surabaya

The study done by the writer observes the themes and rhemes used in the five-star hotels' web sites in Surabaya. It includes the types of themes and the notions of subject which are under the Systemic Functional Grammar (SFG) proposed by Halliday and Matthiessen (2004). In addition, the data of the study are in the form of text and taken from seven Surabaya five-star hotels' web sites. The writer also used a descriptive qualitative approach in analyzing the 155 data. From the analysis, it is found the two kinds of structure of theme and rheme used by the hotels in their web sites. The hotels also used three types of theme which are simple theme, clause as a theme, and thematic equative. In terms of the subjects (psychological subject, grammatical subject, and logical subject), the hotels are able to fulfill either one, two, or three notions of subject