589 research outputs found
Weak boson fusion production of supersymmetric particles at the LHC
We present a complete calculation of weak boson fusion production of
colorless supersymmetric particles at the LHC, using the new matrix element
generator SUSY-MadGraph. The cross sections are small, generally at the
attobarn level, with a few notable exceptions which might provide additional
supersymmetric parameter measurements. We discuss in detail how to consistently
define supersymmetric weak couplings to preserve unitarity of weak gauge boson
scattering amplitudes to fermions, and derive sum rules for weak supersymmetric
couplings.Comment: 24 p., 3 fig., 9 tab., published in PRD; numbers in Table IV
corrected to those with kinematic cuts cite
Determining the Structure of Higgs Couplings at the LHC
Higgs boson production via weak boson fusion at the CERN Large Hadron
Collider has the capability to determine the dominant CP nature of a Higgs
boson, via the tensor structure of its coupling to weak bosons. This
information is contained in the azimuthal angle distribution of the two
outgoing forward tagging jets. The technique is independent of both the Higgs
boson mass and the observed decay channel.Comment: 5 pages, 4 figures, version accepted for publication in PR
Robust LHC Higgs Search in Weak Boson Fusion
We demonstrate that an LHC Higgs search in weak boson fusion production with
subsequent decay to weak boson pairs is robust against extensions of the
Standard Model or MSSM involving a large number of Higgs doublets. We also show
that the transverse mass distribution provides unambiguous discrimination of a
continuum Higgs signal from the Standard Model.Comment: 12p, 2 figs., additional comments on backgrounds, version to appear
in PR
Next-to-leading order jet distributions for Higgs boson production via weak-boson fusion
The weak-boson fusion process is expected to provide crucial information on
Higgs boson couplings at the Large Hadron Collider at CERN. The achievable
statistical accuracy demands comparison with next-to-leading order QCD
calculations, which are presented here in the form of a fully flexible parton
Monte Carlo program. QCD corrections are determined for jet distributions and
are shown to be modest, of order 5 to 10% in most cases, but reaching 30%
occasionally. Remaining scale uncertainties range from order 5% or less for
distributions to below +-2% for the Higgs boson cross section in typical
weak-boson fusion search regions.Comment: 19 pages, 8 figure
Probing Trilinear Gauge Boson Interactions via Single Electroweak Gauge Boson Production at the LHC
We analyze the potential of the CERN Large Hadron Collider (LHC) to study
anomalous trilinear vector-boson interactions W^+ W^- \gamma and W^+ W^- Z
through the single production of electroweak gauge bosons via the weak boson
fusion processes q q -> q q W (-> \ell^\pm \nu) and q q -> q q Z(-> \ell^+
\ell^-) with \ell = e or \mu. After a careful study of the standard model
backgrounds, we show that the single production of electroweak bosons at the
LHC can provide stringent tests on deviations of these vertices from the
standard model prediction. In particular, we show that single gauge boson
production exhibits a sensitivity to the couplings \Delta \kappa_{Z,\gamma}
similar to that attainable from the analysis of electroweak boson pair
production.Comment: 20 pages, 6 figure
Transport Properties of Ground State Nitrogen Atoms
Transport properties of dilute monatomic gases depend on the two body atom-atom interaction potential. When two ground state (4S) nitrogen atoms interact, they can follow any of four potential energy curves corresponding to the N2 molecule; the X 1ÎŁ+g, A3ÎŁ+u, 5ÎŁ+g, and 7ÎŁ+u curves. Transport collision integrals for the 1ÎŁ+g and 3ÎŁ+u states have been calculated by representing the potentials for these states with the Hulburt-Hirschfelder potential. The5ÎŁ+g state has a large local maximum which requires changes in the computational procedure used previously; a modified Hulburt-Hirschfelder potential has been used to represent the potential for this state. Collision integrals for the 7ÎŁ+u state have been obtained by direct use of a recent theoretical potential for this state. The collision integrals are compared with results obtained in previous studies
Top Background Extrapolation for H -> WW Searches at the LHC
A leading order (LO) analysis is presented that demonstrates that key top
backgrounds to H -> W^+W^- -> l^\pm l^\mp \sla{p}_T decays in weak boson fusion
(WBF) and gluon fusion (GF) at the CERN Large Hadron Collider can be
extrapolated from experimental data with an accuracy of order 5% to 10%. If LO
scale variation is accepted as proxy for the theoretical error, parton level
results indicate that the tt~j background to the H -> WW search in WBF can be
determined with a theoretical error of about 5%, while the tt~ background to
the H -> WW search in GF can be determined with a theoretical error of better
than 1%. Uncertainties in the parton distribution functions contribute an
estimated 3% to 10% to the total error.Comment: 17 pages, 9 tables, 4 figures; LO caveat emphasized, version to be
published in Phys. Rev.
Characteristic slepton signal in anomaly mediated SUSY breaking models via gauge boson fusion at the LHC
We point out that slepton pairs produced via gauge boson fusion in anomaly
mediated supersymmetry breaking (AMSB) model have very characteristic and
almost clean signal at the Large Hadron Collider. In this article, we discuss
how one lepton associated with missing energy and produced in between two
high- and high-mass forward jets can explore quite heavy sleptons in this
scenario.Comment: Version to appear in Physical Review
Experimental Verification of 3D Plasmonic Cloaking in Free-Space
We report the experimental verification of metamaterial cloaking for a 3D
object in free space. We apply the plasmonic cloaking technique, based on
scattering cancellation, to suppress microwave scattering from a finite-length
dielectric cylinder. We verify that scattering suppression is obtained all
around the object in the near- and far-field and for different incidence
angles, validating our measurements with analytical results and full-wave
simulations. Our near-field and far-field measurements confirm that realistic
and robust plasmonic metamaterial cloaks may be realized for elongated 3D
objects with moderate transverse cross-section at microwave frequencies.Comment: 12 pages, 8 figures, published in NJ
Measuring Higgs boson couplings at the LHC
For an intermediate mass Higgs boson with SM-like couplings the LHC allows
observation of a variety of decay channels in production by gluon fusion and
weak boson fusion. Cross section ratios provide measurements of various ratios
of Higgs couplings, with accuracies of order 15% for 100 fb^{-1} of data in
each of the two LHC experiments. For Higgs masses above 120 GeV, minimal
assumptions on the Higgs sector allow for an indirect measurement of the total
Higgs boson width with an accuracy of 10 to 20%, and of the H-->WW partial
width with an accuracy of about 10%.Comment: 25 pages, Revtex, 1 figur
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