51,564 research outputs found
Higgs boson production with one bottom quark including higher-order soft-gluon corrections
A Higgs boson produced in association with one or more bottom quarks is of
great theoretical and experimental interest to the high-energy community. A
precise prediction of its total and differential cross-section can have a great
impact on the discovery of a Higgs boson with large bottom-quark Yukawa
coupling, like the scalar (h^0 and H^0) and pseudoscalar (A^0) Higgs bosons of
the Minimal Supersymmetric Standard Model (MSSM) in the region of large
\tan\beta. In this paper we apply the threshold resummation formalism to
determine both differential and total cross-sections for b g \to b\Phi (where
\Phi = h^0, H^0), including up to next-to-next-to-next-to-leading order (NNNLO)
soft plus virtual QCD corrections at next-to-leading logarithmic (NLL)
accuracy. We present results for both the Fermilab Tevatron and the CERN Large
Hadron Collider (LHC).Comment: revtex4, 13 pages, 11 figures; new references and additional comment
Chiral-logarithmic Corrections to the S and T Parameters in Higgsless Models
Recently, Higgsless models have proven to be viable alternatives to the
Standard Model (SM) and supersymmetric models in describing the breaking of the
electroweak symmetry. Whether extra-dimensional in nature or their
deconstructed counterparts, the physical spectrum of these models typically
consists of ``towers'' of massive vector gauge bosons which carry the same
quantum numbers as the SM W and Z. In this paper, we calculate the one-loop,
chiral-logarithmic corrections to the S and T parameters from the lightest
(i.e. SM) and the next-to-lightest gauge bosons using a novel application of
the Pinch Technique. We perform our calculation using generic Feynman rules
with generic couplings such that our results can be applied to various models.
To demonstrate how to use our results, we calculate the leading
chiral-logarithmic corrections to the S and T parameters in the deconstructed
three site Higgsless model. As we point out, however, our results are not
exclusive to Higgsless models and may, in fact, be used to calculate the
one-loop corrections from additional gauge bosons in models with fundamental
(or composite) Higgs bosons.Comment: 45 pages, 15 figures, added references, analysis of three site model
expanded to include delocalized fermion
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