1,965 research outputs found

    Baryon Stability on the Higgs Dissolution Edge : Threshold corrections and suppression of Baryon violation in the NMSGUT

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    Superheavy threshold corrections to the matching condition between matter Yukawa couplings of the effective Minimal Supersymmetric Standard Model (MSSM) and the New Minimal Supersymmetric (SO(10)) GUT(NMSGUT) provide a novel and generic mechanism for reducing the long standing and generically problematic operator dimension 5 Baryon decay rates. In suitable regions of the parameter space strong wave function renormalization of the effective MSSM Higgs doublets due to the large number of heavy fields can take the wave function renormalization of the MSSM Higgs field close to the dissolution value (ZH,H=0Z_{H,\overline{H}}=0). Rescaling to canonical kinetic terms lowers the SO(10) Yukawas required to match the MSSM fermion data. Since the same Yukawas determine the dimension 5 B violation operator coefficients, the associated rates can be suppressed to levels compatible with current limits. Including these threshold effects also relaxes the constraint ybyτysyμ y_b-y_\tau\simeq y_s-y_\mu operative between 10120\textbf{10} -\textbf{120} plet generated tree level MSSM matter fermion Yukawas yfy_f. We exhibit accurate fits of the MSSM fermion mass-mixing data in terms of NMSGUT superpotential couplings and 5 independent soft Susy breaking parameters specified at 1016.2510^{16.25}\, GeV with the claimed suppression of Baryon decay rates. As before, our s-spectra are of the mini split supersymmetry type with large A0,μ,mH,H>100|A_0|,\mu,m_{H,\overline H} > 100\,\, TeV, light gauginos and normal s-hierarchy. Large A0,μA_0,\mu and soft masses allow significant deviation from the canonical GUT gaugino mass ratios and ensure vacuum safety. Even without optimization, prominent candidates for BSM discovery such as the muon magnetic anomaly, bsγb\rightarrow s\gamma and Lepto-genesis CP violation emerge in the preferred ball park.Comment: PdfLatex. 50 pages. Version accepted for publication in Nuclear Phys.B(2014). Available online at http://dx.doi.org/10.1016/j.nuclphysb.2014.03.003. arXiv admin note: substantial text overlap with arXiv:1107.296

    Photoionization in the time and frequency domain

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    Ultrafast processes in matter, such as the electron emission following light absorption, can now be studied using ultrashort light pulses of attosecond duration (101810^{-18}s) in the extreme ultraviolet spectral range. The lack of spectral resolution due to the use of short light pulses may raise serious issues in the interpretation of the experimental results and the comparison with detailed theoretical calculations. Here, we determine photoionization time delays in neon atoms over a 40 eV energy range with an interferometric technique combining high temporal and spectral resolution. We spectrally disentangle direct ionization from ionization with shake up, where a second electron is left in an excited state, thus obtaining excellent agreement with theoretical calculations and thereby solving a puzzle raised by seven-year-old measurements. Our experimental approach does not have conceptual limits, allowing us to foresee, with the help of upcoming laser technology, ultra-high resolution time-frequency studies from the visible to the x-ray range.Comment: 5 pages, 4 figure

    Modal analysis using a Fourier analyzer, curve-fitting, and modal tuning

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    The proposed modal test program differs from single-input methods in that preliminary data may be acquired using multiple inputs, and modal tuning procedures may be employed to define closely spaced frquency modes more accurately or to make use of frequency response functions (FRF's) which are based on several input locations. In some respects the proposed modal test proram resembles earlier sine-sweep and sine-dwell testing in that broadband FRF's are acquired using several input locations, and tuning is employed to refine the modal parameter estimates. The major tasks performed in the proposed modal test program are outlined. Data acquisition and FFT processing, curve fitting, and modal tuning phases are described and examples are given to illustrate and evaluate them

    Investigation of organic adhesives for hybrid microcircuits

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    The properties of organic adhesives were investigated to acquire information for a guideline document regarding the selection of adhesives for use in high reliability hybrid microcircuits. Specifically, investigations were made of (1) alternate methods for determining the outgassing of cured adhesives, (2) effects of long term aging at 150 C on the electrical properties of conductive adhesives, (3) effects of shelf life age on adhesive characteristics, (4) bond strengths of electrically conductive adhesives on thick film gold metallization, (5) a copper filled adhesive, (6) effects of products outgassed from cured adhesives on device electrical parameters, (7) metal migration from electrically conductive adhesives, and (8) ionic content of electrically insulative adhesives. The tests performed during these investigations are described, and the results obtained are discussed

    High harmonic generation from Bloch electrons in solids

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    We study the generation of high harmonic radiation by Bloch electrons in a model transparent solid driven by a strong mid-infrared laser field. We solve the single-electron time-dependent Schr\"odinger equation (TDSE) using a velocity-gauge method [New J. Phys. 15, 013006 (2013)] that is numerically stable as the laser intensity and number of energy bands are increased. The resulting harmonic spectrum exhibits a primary plateau due to the coupling of the valence band to the first conduction band, with a cutoff energy that scales linearly with field strength and laser wavelength. We also find a weaker second plateau due to coupling to higher-lying conduction bands, with a cutoff that is also approximately linear in the field strength. To facilitate the analysis of the time-frequency characteristics of the emitted harmonics, we also solve the TDSE in a time-dependent basis set, the Houston states [Phys. Rev. B 33, 5494 (1986)], which allows us to separate inter-band and intra-band contributions to the time-dependent current. We find that the inter-band and intra-band contributions display very different time-frequency characteristics. We show that solutions in these two bases are equivalent under an unitary transformation but that, unlike the velocity gauge method, the Houston state treatment is numerically unstable when more than a few low lying energy bands are used

    On cross-diffusion systemsfor two populations subject to a common congestion effect

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    In this paper, we investigate the existence of solution for systems of Fokker-Planck equations coupled through a common nonlinear congestion. Two different kinds of congestion are considered: a porous media congestion or \textit{soft} congestion and the \textit{hard} congestion given by the constraint ρ1+ρ21\rho_1+\rho_2 \leqslant 1. We show that these systems can be seen as gradient flows in a Wasserstein product space and then we obtain a constructive method to prove the existence of solutions. Therefore it is natural to apply it for numerical purposes and some numerical simulations are included
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