Probing the Higgs mechanism via γγ→W+W−\gamma\gamma\to W^+W^-

We investigate the sensitivity of the reaction $\gamma\gamma\to W^+W^-$ to the Higgs sector based on the complete one-loop corrections in the minimal Standard Model and the gauged non-linear $\sigma$-model. While this sensitivity is very strong for the suppressed cross-section of equally polarized photons and longitudinal W bosons, it is only marginal for the dominant mode of transverse polarizations. The corrections within the $\sigma$-model turn out to be UV-finite in accordance with the absence of \log\MH terms in the Standard Model with a heavy Higgs boson.Comment: 12 pages uuencoded postscrip

Application of remote sensing to state and regional problems

The author has identified the following significant results. The Lowndes County data base is essentially complete with 18 primary variables and 16 proximity variables encoded into the geo-information system. The single purpose, decision tree classifier is now operational. Signatures for the thematic extraction of strip mines from LANDSAT Digital data were obtained by employing both supervised and nonsupervised procedures. Dry, blowing sand areas of beach were also identified from the LANDSAT data. The primary procedure was the analysis of analog data on the I2S signal slicer

Application of remote sensing to state and regional problems

There are no author-identified significant results in this report

Observation of Leggett's collective mode in a multi-band MgB2 superconductor

We report observation of Leggett's collective mode in a multi-band MgB2 superconductor with T_c=39K arising from the fluctuations in the relative phase between two superconducting condensates. The novel mode is observed by Raman spectroscopy at 9.4 meV in the fully symmetric scattering channel. The observed mode frequency is consistent with theoretical considerations based on the first principle computations.Comment: Accepted for PR

The Minimal Phantom Sector of the Standard Model: Higgs Phenomenology and Dirac Leptogenesis

We propose the minimal, lepton-number conserving, SU(3)xSU(2)xU(1) gauge-singlet, or phantom, extension of the Standard Model. The extension is natural in the sense that all couplings are of O(1) or forbidden due to a phantom sector global U(1)_D symmetry, and basically imitates the standard Majorana see-saw mechanism. Spontaneous breaking of the U(1)_D symmetry triggers consistent electroweak gauge symmetry breaking only if it occurs at a scale compatible with small Dirac neutrino masses and baryogenesis through Dirac leptogenesis. Dirac leptogenesis proceeds through the usual out-of-equilibrium decay scenario, leading to left and right-handed neutrino asymmetries that do not fully equilibrate after they are produced. The model contains two physical Higgs bosons and a massless Goldstone boson. The existence of the Goldstone boson suppresses the Higgs to bb branching ratio and instead the Higgs bosons will mainly decay to invisible Goldstone and/or to visible vector boson pairs. In a representative scenario, we estimate that with 30 fb^-1 integrated luminosity, the LHC could discover this invisibly decaying Higgs, with mass ~120 GeV. At the same time a significantly heavier, partner Higgs boson with mass ~210 GeV could be found through its vector boson decays. Electroweak constraints as well as astrophysical and cosmological implications are analysed and discussed.Comment: 21 pages, 4 figures. Corrected typos and added references. To appear in JHE

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Effects of R-parity Violation on the Charged Higgs Boson Decays

We calculate one-loop R-parity-violating couplings corrections to the processes $H^-\to \tau\bar{\nu_\tau}$ and $H^-\to b\bar{t}$. We find that the corrections to the $H^-\to \tau\bar{\nu_\tau}$ decay mode are generally about 0.1%, and can be negligible. But the corrections to the $H^-\to b\bar{t}$ decay mode can reach a few percent for the favored parameters.Comment: 17 pages,6 figures. One type error in the title correcte

Does Magnetic Charge Imply a Massive Photon ?

In Abelian theories of monopoles the magnetic charge is required to be enormous. Using the electric-magnetic duality of electromagnetism it is argued that the existence of such a large, non-perturbative magnetic coupling should lead to a phase transition where magnetic charge is permanently confined and the photon becomes massive. The apparent masslessness of the photon could then be used as an argument against the existence of such a large, non-perturbative magnetic charge. Finally it is shown that even in the presence of this dynamical mass generation the Cabbibo-Ferrari formulation of magnetic charge gives a consistent theory.Comment: 10 pages LaTe

Bloch-Nordsieck Violation in Spontaneously Broken Abelian Theories

We point out that, in a spontaneously broken U(1) gauge theory, inclusive processes, whose primary particles are mass eigenstates that do not coincide with the gauge eigenstates, are not free of infrared logarithms. The charge mixing allowed by symmetry breaking and the ensuing Bloch-Nordsieck violation are here analyzed in a few relevant cases and in particular for processes initiated by longitudinal gauge bosons. Of particular interest is the example of weak hypercharge in the Standard Model where, in addition, left-right mixing effects arise in transversely polarized fermion beams.Comment: 4 pages, 1 figur

Higgs Radiation off Top Quarks at the Tevatron and the LHC

Higgs bosons can be searched for in the channels $p\bar p/pp\to t\bar tH+X$ at the Tevatron and the LHC. We have calculated the QCD corrections to these processes in the Standard Model at next-to-leading order. The higher-order corrections reduce the renormalization and factorization scale dependence considerably and stabilize the theoretical predictions for the cross sections. At the central scale $\mu=(2m_t+M_H)/2$ the properly defined $K$ factors are slightly below unity for the Tevatron ($K \sim 0.8$) and slightly above unity for the LHC ($K \sim 1.2$).Comment: 5 pages, latex, 2 figure