122 research outputs found
Next-to-leading order QCD predictions for the hadronic +jet production
We calculate the next-to-leading order(NLO) QCD corrections to the
production in association with a jet at hadron colliders. We study the impacts
of the complete NLO QCD radiative corrections to the integrated cross sections,
the scale dependence of the cross sections, and the differential cross sections
(, ) of the final -,
Higgs-boson and jet. We find that the corrections significantly modify the
physical observables, and reduce the scale uncertainty of the LO cross section.
Our results show that by applying the inclusive scheme with and taking , , the
K-factor is 1.15 for the process at the Tevatron,
while the K-factors for the processes and
at the LHC are 1.12 and 1.08 respectively. We conclude that to understand the
hadronic associated production, it is necessary to study the NLO QCD
corrections to production process which is part of the inclusive
production.Comment: 26 pages, 27 figures, accepted by Phys. Rev.
Jet-veto in bottom-quark induced Higgs production at next-to-next-to-leading order
We present results for associated Higgs+n-jet production in bottom quark
annihilation, for n=0 and n>=1 at NNLO and NLO accuracy, respectively. We
consider both the cases with and without b-tagging. Numerical results are
presented for parameters relevant for experiments at the LHC.Comment: 27 pages, 13 figures, 8 table
The MSSM prediction for W+/- H-/+ production by gluon fusion
We discuss the associated W+/- H-/+ production in p p collision for the Large
Hadron Collider. A complete one-loop calculation of the loop-induced subprocess
g g -> W+/- H-/+ is presented in the framework of the Minimal Supersymmetric
Standard Model (MSSM), and the possible enhancement of the hadronic cross
section is investigated under the constraint from the squark direct-search
results and the low-energy precision data. Because of the large destructive
interplay in the quark-loop contributions between triangle-type and box-type
diagrams, the squark-loop contributions turn out to be comparable with the
quark-loop ones. In particular, the hadronic cross section via gluon fusion can
be extensively enhanced by squark-pair threshold effects in the box-type
diagrams, so that it can be as large as the hadronic cross section via the b
b-bar -> W+/- H-/+ subprocess which appears at tree level.Comment: 35 pages, 7 figures, version to appear in Physical Review
LeistungsfÀhigkeit von RettungsgerÀten der Feuerwehr bei der Rettung von Personen aus Obergeschossen baulicher Anlagen
Zur Ermittlung der âLeistungsfĂ€higkeit von RettungsgerĂ€ten der Feuerwehr bei der Rettung von Personen aus Obergeschossen baulicher Anlagenâ sollte ein Fragebogen erarbeitet und an 100 Feuerwehren ver-schickt werden. Aufgrund unklarer Formulierungen der Fragen waren auch die Antworten nicht eindeutig und somit konnte die Auswertung der ausgefĂŒllten Fragebögen keine nutzbaren Erkenntnisse bringen. Um dennoch verwertbare Erkenntnisse zu gewinnen, wurden Versuchsreihen mit verschiedenen Feuerweh-ren durchgefĂŒhrt, bei denen die Rettungszeiten adipöser Personen, mittels Krankentrage auf die Drehleiter, untersucht wurden
MSSM Higgs bosons associated with high-pT jets at hadron colliders
The cross section for the production of the lightest neutral Higgs boson in
association with a high-pT hadronic jet, calculated in the framework of the
minimal supersymmetric standard model (MSSM), is presented. The expectations
for the hadronic cross section at the Large Hadron Collider are discussed using
reasonable kinematical cuts. In particular the contributions from superpartner
loops to the cross section and their dependence on the parameters of the MSSM
are investigated and found to be significant. Comparisons show that the
production rate for h0 + jet in the MSSM can differ widely from the
corresponding standard-model prediction.Comment: 20 page
Gauge-independent renormalization in the 2HDM
We present a consistent renormalization scheme for the CP-conserving
Two-Higgs-Doublet Model based on renormalization of the mixing
angles and the soft--symmetry-breaking scale in the Higgs sector.
This scheme requires to treat tadpoles fully consistently in all steps of the
calculation in order to provide gauge-independent -matrix elements. We show
how bare physical parameters have to be defined and verify the gauge
independence of physical quantities by explicit calculations in a general
-gauge. The procedure is straightforward and applicable to other
models with extended Higgs sectors. In contrast to the proposed scheme, the
renormalization of the mixing angles combined with popular
on-shell renormalization schemes gives rise to gauge-dependent results already
at the one-loop level. We present explicit results for electroweak NLO
corrections to selected processes in the appropriately renormalized
Two-Higgs-Doublet Model and in particular discuss their scale dependence.Comment: 52 pages, PDFLaTeX, PDF figures, JHEP version with Eq. (5.23)
correcte
Production of the neutral top-pion in association with a high- jet at the
In the framework of the topcolor-assisted technicolor model, we study
production of the neutral top-pion in association with a
high- jet at the , which proceeds via the partonic processes
, ,
, , and . We find
that it is very challenging to detect the neutral top-pion via
the process , while the
possible signatures of might be detected via the process
at the .Comment: 13 pages, 4 figures; typos correcte
Analytic Results for Higgs Production in Bottom Fusion
We evaluate analytically the cross section for Higgs production plus one jet
through bottom quark fusion. By considering the small pT limit we derive
expressions for the resummation coefficients governing the structure of large
logarithms, and compare these expressions with those available in the
literature.Comment: 14 pages, 7 figure
Charged Higgs Boson Production in Bottom-Gluon Fusion
We compute the complete next-to-leading order SUSY-QCD corrections for the
associated production of a charged Higgs boson with a top quark via
bottom-gluon fusion. We investigate the applicability of the bottom parton
description in detail. The higher order corrections can be split into real and
virtual corrections for a general two Higgs doublet model and into additional
massive supersymmetric loop contributions. We find that the perturbative
behavior is well under control. The supersymmetric contributions consist of the
universal bottom Yukawa coupling corrections and non-factorizable diagrams.
Over most of the relevant supersymmetric parameter space the Yukawa coupling
corrections are sizeable, while the remaining supersymmetric loop contributions
are negligible.Comment: 18 pages, v2: some discussions added, v3: published versio
Higgs-Boson Production Induced by Bottom Quarks
Bottom quark-induced processes are responsible for a large fraction of the
LHC discovery potential, in particular for supersymmetric Higgs bosons.
Recently, the discrepancy between exclusive and inclusive Higgs boson
production rates has been linked to the choice of an appropriate bottom
factorization scale. We investigate the process kinematics at hadron colliders
and show that it leads to a considerable decrease in the bottom factorization
scale. This effect is the missing piece needed to understand the corresponding
higher order results. Our results hold generally for charged and for neutral
Higgs boson production at the LHC as well as at the Tevatron. The situation is
different for single top quark production, where we find no sizeable
suppression of the factorization scale. Turning the argument around, we can
specify how large the collinear logarithms are, which can be resummed using the
bottom parton picture.Comment: 18 page
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