Models of Flavor with Discrete Symmetries

In an attempt to understand the observed patterns of lepton and quark masses, models invoking a flavor symmetry $G_f$, under which the Standard Model generations are charged, have been proposed. One particularly successful symmetry, U(2), has been extensively discussed in the literature. The Yukawa matrices in models based on this symmetry reproduce the observed mass ratios in the lepton and quark sectors. The features of the symmetry that determine the texture of the Yukawa matrices can be found in other symmetries as well. We present a model based on a minimal, non-Abelian discrete symmetry that reproduces the Yukawa matrices associated with U(2) theories of flavor. In addition to reproducing the mass and mixing angle relations obtained in such theories, the different representation structure of our new horizontal symmetry allows for solutions to the solar and atmospheric neutrino problems.Comment: Prepared for the 8th Mexican Workshop on Particles and Fields, Zacatecas, Mexico; 14-20 November, 200

Fine gradings on simple exceptional Jordan pairs and triple systems

We give a classification up to equivalence of the fine group gradings by abelian groups on the Jordan pairs and triple systems of types bi-Cayley and Albert, under the assumption that the base field is algebraically closed of characteristic different from $2$. The associated Weyl groups are computed. We also determine, for each fine grading on the bi-Cayley and Albert pairs, the induced grading on the exceptional simple Lie algebra given by the Tits-Kantor-Koecher construction.Comment: 47 pages. Updated version. Accepted for publication in Journal of Algebr

Why biologists should read Aristotle (or why philosophy matters for the life sciences and why the life sciences matter for philosophy)

This note discusses the importance of Natural History (biology) in the development of Aristotle philosophy and scientific outlook, and so the importance of considering Aristotle's philosophy as a necessary and useful background for contemporary biology

Standard Model Extension with Flipped Generations

An extension of the Standard Model is presented that leads to the possible existence of new gauge bosons with masses in the range of a few TeV. Due to the fact that their couplings to Standard Model fermions are strongly suppressed, it is possible for them to be hidden from current searches. The model contains additional generations of fermions with quantum numbers resembling those of the Standard Model fermion generations but with a twist: their charge assignments are such that their electric charges and chiralities are flipped with respect to those of their corresponding Standard Model counterparts. This feature provides a way to obtain potential dark matter candidates and the interesting possibility for a Lepton number conserving dimension-five operator for Dirac neutrino masses. The model implications associated to electroweak precision parameters, flavor changing neutral currents, and diphoton rate contributions are briefly discussed. The general assumptions of this set up are also used to sketch a couple of variants of the model with peculiar features that could motivate further study.Comment: 8 pages, 3 figures, 2 tables. Discussion on W' boson and RH neutrinos extended, references added, typos corrected, title changed. Matches published version in PL

Constraints on realistic Gauge-Higgs unified models

We investigate the general group structure of gauge-Higgs unified models. We find that a given embedding of the \sm\ gauge group will imply the presence of additional light vectors, except for a small set of special cases, which we determine; the arguments presented are independent of the compactification scheme. For this set of models we then find those that can both accommodate quarks and have a vanishing oblique T-parameter at tree-level. We show that none of the resulting models can have |\sw| \sim1/2 (the sine of the weak-mixing angle) at tree-level and briefly discuss possible solutions to this problem.Comment: 22 pages, 2 appendixes, 6 tables. Minor changes and references added. Version to appear in PR

Powder diffraction at ALBA synchrotron

This talk is devoted to explain the uses of powder diffraction at MSPD (material science and powder diffraction) of ALBA synchrotron light source. General characteristics of the beamline are: Station 1 - High Pressure Diffraction on powders with diamond anvil cell (DAC) and CCD detector. Microdiffraction; and Station 2 - High Resolution Powder Diffraction with Multicrystal- and Silicon-Strip detector. Energy Range: 8-50keV; Typical beam size: 4x1mm; all typical sample geometries possible: capillary, reflection and flat sample in transmission. Initially the setups are described in detail both in the optics hutch and in the experimental hutch. In the high-pressure end station, we can highlight: i) sample alignment semi-automatic; ii) data acquisition and reduction integrated within the beamline control system; iii) online pressure calibration system operational and several upgrades which are under commissioning: i) system for Membrane DAC, Automatic Drive System (change the pressure from outside the hutch); ii) Gas Membrane kit for Almax-Boehler DAC cell (from screw-driven to gas membrane driven); iii) low temperature cryostat and high temperature DAC cell projects are on-going. In the high resolution powder diffraction end station, we can highlight: i) a diffractometer with 3 concentric rotary stages (for two detectors); ii) one very high resolution detector MAD26 (10 – 50KeV), devoted to high resolution ~0.005° [13 channels with 1.5 deg pitch, Si111 Bragg crystals, YAP scintillator + PMT]; iii) MythenII (8 – 30 keV) for fast acquisitions [6 modules that cover 40 deg 0.005 pitch angle, with millisecond resolution]; iv) Temperature range 80 – 900K; v) Eulerian Cradle optional. Then, the main applications will be dealt with based on examples that expands from structure solution of zeolites to the in-situ studies of perovskite catalyst under H2 atmosphere at high temperatures. The high-pressure studies will be exemplified by studies of materials in DAC.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Powder diffraction at ALBA synchrotron

This talk is devoted to explain the uses of powder diffraction at MSPD (material science and powder diffraction) of ALBA synchrotron light source. General characteristics of the beamline are: Station 1 - High Pressure Diffraction on powders with diamond anvil cell (DAC) and CCD detector. Microdiffraction; and Station 2 - High Resolution Powder Diffraction with Multicrystal- and Silicon-Strip detector. Energy Range: 8-50keV; Typical beam size: 4x1mm; all typical sample geometries possible: capillary, reflection and flat sample in transmission. Initially the setups are described in detail both in the optics hutch and in the experimental hutch. In the high-pressure end station, we can highlight: i) sample alignment semi-automatic; ii) data acquisition and reduction integrated within the beamline control system; iii) online pressure calibration system operational and several upgrades which are under commissioning: i) system for Membrane DAC, Automatic Drive System (change the pressure from outside the hutch); ii) Gas Membrane kit for Almax-Boehler DAC cell (from screw-driven to gas membrane driven); iii) low temperature cryostat and high temperature DAC cell projects are on-going. In the high resolution powder diffraction end station, we can highlight: i) a diffractometer with 3 concentric rotary stages (for two detectors); ii) one very high resolution detector MAD26 (10 – 50KeV), devoted to high resolution ~0.005° [13 channels with 1.5 deg pitch, Si111 Bragg crystals, YAP scintillator + PMT]; iii) MythenII (8 – 30 keV) for fast acquisitions [6 modules that cover 40 deg 0.005 pitch angle, with millisecond resolution]; iv) Temperature range 80 – 900K; v) Eulerian Cradle optional. Then, the main applications will be dealt with based on examples that expands from structure solution of zeolites to the in-situ studies of perovskite catalyst under H2 atmosphere at high temperatures. Total scattering (pair distribution function analysis) will also be presented. The high-pressure studies will be exemplified by studies of materials in DAC.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech