58,436 research outputs found
Higgs Boson Mass Bounds in the Standard and Minimal Supersymmetric Standard Model with Four Generations
We study the question of distinguishability of the Higgs sector between the
standard model with four generations(SM4) and the minimal supersymmetric
standard model with four generations (MSSM4). We find that a gap exists between
the SM4 and MSSM4 Higgs boson masses for a range of the fourth generation
fermion mass considered in the analysis at a fixed top quark mass. We also
compare the Higgs boson mass bounds in these models with those in the standard
and the minimal supersymmetric standard models.Comment: 11 pages, Revtex, 3 postscript figures, accepted for publication in
Mod. Phys. Lett.
Pressure effects on the superconducting thin film BaKFeAs
We report electrical resistivity measurements on a high-quality
BaKFeAs thin film () under pressure. The
superconducting transition temperature (=39.95 K) of the optimally-doped thin
film shows a dome shape with pressure, reaching a maximal value 40.8 K at 11.8
kbar. The unusually high superconducting transition temperature and its
anomalous pressure dependence are ascribed to a lattice mismatch between the
LaAlO substrate and the thin film. The local temperature exponent of the
resistivity () shows a funnel shape around
the optimal pressure, suggesting that fluctuations associated with the
anomalous normal state are responsible for high-temperature superconductivity.Comment: To appear in Appl. Phys. Let
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