QCD Corrections in two-Higgs-doublet extensions of the Standard Model with Minimal Flavor Violation

We present the QCD corrections to R_b and to the Delta B=1 effective Hamiltonian in models with a second Higgs field that couples to the quarks respecting the criterion of Minimal Flavor Violation, thus belonging either to the (1,2)_1/2 or to the (8,2)_1/2 representation of SU(3)xSU(2)xU(1). After the inclusion of the QCD corrections, the prediction for R_b becomes practically insensitive to the choice of renormalization scheme for the top mass, which for the type-I and type-II models translates in a more robust lower bound on tan(beta). The QCD-corrected determinations of Rb and BR(B->Xs gamma) are used to discuss the constraints on the couplings of a (colored) charged Higgs boson to top and bottom quarks.Comment: 19 pages, 7 figures. v2: version published in Phys. Rev. D, with additional reference and not

SOFIA: A Stratospheric Observatory for Infrared Astronomy

SOFIA is described as it was originally (May 1988) for the Space and Earth Sciences Advisory Committee (SESAC). The format and questions were provided by SESAC as a standard for judging the merit of potential U.S. space science projects. This version deletes Section IIF, which addressed development costs of the SOFIA facility. SOFIA's unique astronomical potential is described and it is shown how it complements and supports existing and planned facilities

Unitary ambiguity in the extraction of the E2/M1 ratio for the γN↔Δ\gamma N\leftrightarrow\Delta transition

The resonant electric quadrupole amplitude in the transition $\gamma N\leftrightarrow\Delta(1232)$ is of great interest for the understanding of baryon structure. Various dynamical models have been developed to extract it from the corresponding photoproduction multipole of pions on nucleons. It is shown that once such a model is specified, a whole class of unitarily equivalent models can be constructed, all of them providing exactly the same fit to the experimental data. However, they may predict quite different resonant amplitudes. Therefore, the extraction of the E2/M1($\gamma N\leftrightarrow\Delta$) ratio (bare or dressed) which is based on a dynamical model using a largely phenomenological $\pi N$ interaction is not unique.Comment: 10 pages revtex including 4 postscript figure

Modified Paschos-Wolfenstein relation and extraction of weak mixing angle sin^2 theta_W

The NuTeV collaboration reported anomalously large weak mixing angle sin^2 theta_W in comparison with the standard model prediction. Neutrino and antineutrino charged- and neutral-current events are analyzed for extracting sin^2 theta_W. Although the Paschos-Wolfenstein relation is not directly used in the analysis, it plays an important role in the determination. Noting that the target nucleus, iron, is not an isoscalar nucleus, we derive a leading-order expression for a modified Paschos-Wolfenstein relation for nuclei, which may have neutron excess. Then, using charge and baryon-number conservations for nuclei, we discuss a nuclear correction in the sin^2 theta_W determination. It is noteworthy that nuclear modifications are different between valence up- and down-quark distributions. We show this difference effect on the NuTeV sin^2 theta_W deviation.Comment: 5 pages, REVTeX4.0, revtex4.cls, url.sty, natbib.sty, revsymb.sty, 10pt.rtx, aps.rtx, amssymb.sty, amsfonts.sty, 3 eps figures. Phys. Rev. D in press. Email: [email protected] See also http://hs.phys.saga-u.ac.j

Parametrization of the octupole degrees of freedom

A simple parametrization for the octupole collective variables is proposed and the symmetries of the wave functions are discussed in terms of the solutions corresponding to the vibrational limit. [PACS: 21.60Ev, 21.60.Fw, 21.10.Re]Comment: 14 page

E(5), X(5), and Prolate to Oblate Shape Phase Transitions in Relativistic Hartree Bogoliubov Theory

Relativistic mean field theory with the NL3 force is used for producing potential energy surfaces (PES) for series of isotopes suggested as exhibiting critical point symmetries. Relatively flat PES are obtained for nuclei showing the E(5) symmetry, while in nuclei corresponding to the X(5) case, PES with a bump are obtained. The PES corresponding to the Pt chain of isotopes suggest a transition from prolate to oblate shapes at 186-Pt.Comment: 21 pages, LaTeX, including 14 .eps figure