64 research outputs found
Higgs Boson Production at Hadron Colliders at N3LO in QCD
We present the Higgs boson production cross section at Hadron colliders in
the gluon fusion production mode through N3LO in perturbative QCD.
Specifically, we work in an effective theory where the top quark is assumed to
be infinitely heavy and all other quarks are considered to be massless. Our
result is the first exact formula for a partonic hadron collider cross section
at N3LO in perturbative QCD. Furthermore, this result represents the first
analytic computation of a hadron collider cross section involving elliptic
integrals. We derive numerical predictions for the Higgs boson cross section at
the LHC. Previously this result was approximated by an expansion of the cross
section around the production threshold of the Higgs boson and we compare our
findings. Finally, we study the impact of our new result on the state of the
art prediction for the Higgs boson cross section at the LHC.Comment: several nice figure
The Soft-Virtual Higgs Cross-section at N3LO and the Convergence of the Threshold Expansion
We discuss the validity of the soft-virtual approximation and the threshold
expansion for the Higgs boson production cross-section at hadron colliders in
perturbative QCD up to next-to- next-to-next-to-leading order (N3LO).Comment: Proceedings of Moriond QCD 2014; contains several interesting plot
Four-gluon scattering at three loops, infrared structure and Regge limit
We compute the three-loop four-gluon scattering amplitude in maximally
supersymmetric Yang-Mills theory, including its full color dependence. Our
result is the first complete computation of a non-planar four-particle
scattering amplitude to three loops in four-dimensional gauge theory and
consequently provides highly non-trivial data for the study of non-planar
scattering amplitudes. We present the amplitude as a Laurent expansion in the
dimensional regulator to finite order, with coefficients composed of harmonic
poly-logarithms of uniform transcendental weight, and simple rational
prefactors. Our computation provides an independent check of a recent result
for three-loop corrections to the soft anomalous dimension matrix that predicts
the general infrared singularity structure of massless gauge theory scattering
amplitudes. Taking the Regge limit of our result, we determine the three-loop
gluon Regge trajectory. We also find agreement with very recent predictions for
sub-leading logarithms
iHixs 2 - Inclusive Higgs Cross Sections
We present a new release of the program iHixs. This easy-to-use tool allows
to derive state of the art predictions for the inclusive production cross
section of a Higgs boson at hadron colliders in the gluon fusion production
mode. This includes the most up-to-date corrections in perturbative QCD and
electro-weak theory, effects due to finite quark masses as well as an option to
perform threshold resummation. In particular, exact perturbative QCD
corrections through N3LO are included in the heavy top quark effective theory.
Furthermore, iHixs contains automatic routines that allow to assess residual
uncertainties on the prediction for the Higgs boson production cross section
according to well established standard definitions. iHixs can be obtained from
https://github.com/dulatf/ihixs .Comment: 46 pages, 3 awesome figure
Differential Higgs production at N3LO beyond threshold
We present several key steps towards the computation of differential Higgs
boson cross sections at NLO in perturbative QCD. Specifically, we work in
the framework of Higgs-differential cross sections that allows to compute
precise predictions for realistic LHC observables. We demonstrate how to
perform an expansion of the analytic NLO coefficient functions around the
production threshold of the Higgs boson. Our framework allows us to compute to
arbitrarily high order in the threshold expansion and we explicitly obtain the
first two expansion coefficients in analytic form. Furthermore, we assess the
phenomenological viability of threshold expansions for differential
distributions. In addition, we report on an interesting obstacle for the
computation of NLO corrections with LHAPDF parton distribution functions
and our solution. We provide files containing the analytic expressions for the
partonic cross sections together with the arXiv submission.Comment: 12 plots and 1 Feynman Diagra
Precision Predictions at NLO for the Higgs Boson Rapidity Distribution at the LHC
We present precise predictions for the Higgs boson rapidity distribution at
the LHC in the gluon fusion production mode. Our approach relies on the fully
analytic computation of six terms in a systematic expansion of the partonic
differential cross section around the production threshold of the Higgs boson
at next-to-next-to-next-to leading order (NLO) in QCD perturbation theory.
We observe a mild correction compared to the previous perturbative order and a
significant reduction of the dependence of the cross section on the
perturbative scale throughout the entire rapidity range.Comment: 6 pages, 3 awesome figure
Higgs production in bottom-quark fusion to third order in the strong coupling
We present the inclusive cross section at next-to-next-to-next-to-leading
order (NLO) in perturbative QCD for the production of a Higgs boson via
bottom-quark fusion. We employ the five-flavour scheme, treating the bottom
quark as a massless parton while retaining a non-vanishing Yukawa coupling to
the Higgs boson. We find that the dependence of the hadronic cross section on
the renormalisation and factorisation scales is substantially reduced. For
judicious choices of the scales the perturbative expansion of the cross section
shows a convergent behaviour. We present results for the NLO cross section
at various collider energies. In comparison to the cross section obtained from
the Santander-matching of the four and five-flavour schemes we predict a
slightly higher cross section, though the two predictions are consistent within
theoretical uncertainties.Comment: 3 pretty plots with pretty colours. Published versio
Higgs-differential cross section at NNLO in dimensional regularisation
We present an analytic computation of the Higgs production cross section in
the gluon fusion channel, which is differential in the components of the Higgs
momentum and inclusive in the associated partonic radiation through NNLO in
perturbative QCD. Our computation includes the necessary higher order terms in
the dimensional regulator beyond the finite part that are required for
renormalisation and collinear factorisation at NLO. We outline in detail
the computational methods which we employ. We present numerical predictions for
realistic final state observables, specifically distributions for the decay
products of the Higgs boson in the decay channel.Comment: 27 pages, 6 awesome figure
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