646 research outputs found
Photoproduction of W Bosons at HERA: QCD Corrections
W bosons can be produced in the channels e+- p -> W+- + X at HERA thus
allowing to probe for anomalous trilinear couplings among the gauge bosons. We
discuss the NLO QCD corrections to the photoproduction of W bosons with finite
transverse momentum at HERA. The higher-order QCD corrections reduce the
factorization scale dependence significantly and modify the leading order cross
sections by +-O(10%).Comment: 15 pages, latex, 9 figures, published versio
Photoproduction of W Bosons at HERA: Reweighting Method for implementing QCD Corrections in Monte Carlo Programs
A procedure of implementing QCD corrections in Monte Carlo programs by a
reweighting method is described for the photoproduction of W bosons at HERA.
Tables for W boson production in LO and NLO are given in bins of the transverse
momentum of the W boson and its rapidity.Comment: 39 pages, latex, 5 figure
Exact Hybrid Covariance Thresholding for Joint Graphical Lasso
This paper considers the problem of estimating multiple related Gaussian
graphical models from a -dimensional dataset consisting of different
classes. Our work is based upon the formulation of this problem as group
graphical lasso. This paper proposes a novel hybrid covariance thresholding
algorithm that can effectively identify zero entries in the precision matrices
and split a large joint graphical lasso problem into small subproblems. Our
hybrid covariance thresholding method is superior to existing uniform
thresholding methods in that our method can split the precision matrix of each
individual class using different partition schemes and thus split group
graphical lasso into much smaller subproblems, each of which can be solved very
fast. In addition, this paper establishes necessary and sufficient conditions
for our hybrid covariance thresholding algorithm. The superior performance of
our thresholding method is thoroughly analyzed and illustrated by a few
experiments on simulated data and real gene expression data
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
PIN101 Confirmation of the Factor Structure of the Proqol-HIV Questionnaire to Assess Health-Related Quality of Life in PLWHA
Scalar Particle Contribution to Higgs Production via Gluon Fusion at NLO
We consider the gluon fusion production cross section of a scalar Higgs boson
in models where fermion and scalar massive colored particles are present. We
report analytic expressions for the matrix elements of , , and processes completing the calculation of the NLO QCD
corrections in these extended scenarios. The formulas are written in a complete
general case, allowing a flexible use for different theoretical models.
Applications of our results to two different models are presented: i) a model
in which the SM Higgs sector is augmented by a weak doublet scalar in the
adjoint representation. ii) The MSSM, in the limit of neglecting the
gluino contribution to the cross section.Comment: 20 pages, 5 figures. Minor changes. Refs. adde
Scalar and Pseudoscalar Higgs Boson Plus One Jet Production at the LHC and Tevatron
The production of the Standard Model (SM) Higgs boson (H) in association with
a jet is compared with that of the lightest scalar Higgs boson (h^0) and the
pseudoscalar Higgs boson (A^0) of the Minimal Supersymmetric Model (MSSM) at
both the CERN Large Hadron Collider (LHC) and the Fermilab Tevatron. We include
both top and bottom quark loops to lowest order in QCD and investigate the
limits of zero quark mass and infinite quark mass.Comment: 14 pages, REVTeX4, 14 eps figures v2: Version accepted for
publication in PR
Next-to-leading order QCD predictions for production at LHC
We calculate the complete next-to-leading order (NLO) QCD corrections to the
production in association with a jet at the LHC. We study the impacts
of the NLO QCD radiative corrections to the integrated and differential cross
sections and the dependence of the cross section on the
factorization/renormalization scale. We present the transverse momentum
distributions of the final -, Higgs-boson and leading-jet. We find that
the NLO QCD corrections significantly modify the physical observables, and
obviously reduce the scale uncertainty of the LO cross section. The QCD
K-factors can be 1.183 and 1.180 at the and
LHC respectively, when we adopt the inclusive event selection scheme with
, and . Furthermore, we make the comparison between the two scale
choices, and , and find the scale choice seems to be more
appropriate than the fixed scale .Comment: 18 pages, 7 figure
Higgs production and decay with a fourth Standard-Model-like fermion generation
State-of-the-art predictions for the Higgs-boson production cross section via
gluon fusion and for all relevant Higgs-boson decay channels are presented in
the presence of a fourth Standard-Model-like fermion generation. The
qualitative features of the most important differences to the genuine Standard
Model are pointed out, and the use of the available tools for the predictions
is described. For a generic mass scale of 400-600 GeV in the fourth generation
explicit numerical results for the cross section and decay widths are
presented, revealing extremely large electroweak radiative corrections, e.g.,
to the cross section and the Higgs decay into WW or ZZ pairs, where they amount
to about -50% or more. This signals the onset of a non-perturbative regime due
to the large Yukawa couplings in the fourth generation. An estimate of the
respective large theoretical uncertainties is presented as well.Comment: 24 pages, 5 figures, contribution to LHC Higgs Cross Section Working
Group https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections,
discussion considerably extended to more scenarios for heavy fermion masse
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