16,496 research outputs found

    Zero mode contribution in quarkonium correlators and in-medium properties of heavy quarks

    Full text link
    We calculate the low energy contribution to quarkonium correlators in Euclidean time in lattice QCD. This contribution was found to give the dominant source of the temperature dependence of the correlators. We have found that the low energy contribution is well described by a quasi-particle model and have determined the effective temperature dependent heavy quark mass.Comment: Contribution to QM2008, 4 pages, LaTeX, uses iopart.cls, corrected typo

    Sample-specific and Ensemble-averaged Magnetoconductance of Individual Single-Wall Carbon Nanotubes

    Full text link
    We discuss magnetotransport measurements on individual single-wall carbon nanotubes with low contact resistance, performed as a function of temperature and gate voltage. We find that the application of a magnetic field perpendicular to the tube axis results in a large magnetoconductance of the order of e^2/h at low temperature. We demonstrate that this magnetoconductance consists of a sample-specific and of an ensemble-averaged contribution, both of which decrease with increasing temperature. The observed behavior resembles very closely the behavior of more conventional multi-channel mesoscopic wires, exhibiting universal conductance fluctuations and weak localization. A theoretical analysis of our experiments will enable to reach a deeper understanding of phase-coherent one-dimensional electronic motion in SWNTs.Comment: Replaced with published version. Minor changes in tex

    The charged lepton mass matrix and non-zero θ13\theta_{13} with TeV scale New Physics

    Full text link
    We provide an explicit structure of the charged lepton mass matrix which is 2-3 symmetric except for a single breaking of this symmetry by the muon mass. We identify a flavor symmetric limit for the mass matrices where the first generation is decoupled from the other two in the charged lepton sector while in the neutrino sector the third generation is decoupled from the first two generations. The leptonic mixing in the symmetric limit can be, among other structures, the bi-maximal (BM) or the tri-bimaximal (TBM) mixing. Symmetry breaking effects are included both in the charged lepton and the neutrino sector to produce corrections to the leptonic mixing and explain the recent θ13\theta_{13} measurements. A model that extends the SM by three right handed neutrinos, an extra Higgs doublet, and two singlet scalars is introduced to generate the leptonic mixing.Comment: 28 pages, 24 figures. arXiv admin note: substantial text overlap with arXiv:1111.307
    • …
    corecore