38 research outputs found
Associated W+/- H-/+ production at e+ e- and hadron colliders
We show some results in the minimal supersymmetric Standard Model (MSSM) and
the two Higgs doublet model (THDM) for W+/- H-/+ production cross sections at
e+ e- and hadron colliders. We demonstrate that the predictions for the cross
sections in the two models can be vastly different. Observing these processes,
once the existence of a charged Higgs is established, might shed some light on
the underlying model for an extended Higgs sector.Comment: 8 pages, 5 figures, Contribution to SUSY 02, Hamburg, Germany, June
200
Production of Neutral Higgs + Jet at the LHC in the SM and the MSSM
The cross section prediction for the production of the lightest neutral Higgs
boson in association with a high-p_T hadronic jet is presented in the framework
of the minimal supersymmetric standard model (MSSM) and compared to the SM
case. Prospects for the CERN Large Hadron Collider (LHC) are discussed.Comment: 4 pages, To appear in the Proceedings of SUSY 2003, held at the
University of Arizona, Tucson, AZ, 5-10 June 200
Adaptive scanning - a proposal how to scan theoretical predictions over a multi-dimensional parameter space efficiently
A method is presented to exploit adaptive integration algorithms using
importance sampling, like VEGAS, for the task of scanning theoretical
predictions depending on a multi-dimensional parameter space. Usually, a
parameter scan is performed with emphasis on certain features of a theoretical
prediction. Adaptive integration algorithms are well-suited to perform this
task very efficiently. Predictions which depend on parameter spaces with many
dimensions call for such an adaptive scanning algorithm.Comment: 8 pages, 4 figure
Charged Higgs-boson production in association with an electron and a neutrino at electron-positron colliders
We present results of a calculation of the cross section for the production
of a charged Higgs boson in association with an electron and a neutrino at
electron-positron colliders (e+ e- -> H+ e- nu_e-bar, H- e+ nu_e). We study
predictions for the cross section in the Minimal Supersymmetric Standard Model
(MSSM) and the Two Higgs Doublet Model (THDM), highlighting possible
differences. The process is effectively loop-induced in both models. Hence, the
cross section is expected to be strongly model-dependent. Most notably, due to
the presence of superpartners, the MSSM amplitude contains Feynman graphs of
pentagon-type, which are not present in the THDM. This is the first complete
one-loop calculation of the cross section for this process in the THDM and the
MSSM. For both models, so far, only approximate results with limited ranges of
validity were available. Our main aim here is to clarify several open questions
in the existing literature on this process. Specifically, we will discuss the
validity of the Heavy Fermion loop approximation in both models, and of the
Fermion/Sfermion loop approximation in the MSSM.Comment: 21 pages, 8 figures, 1 tabl
Electroweak and Bottom Quark Contributions to Higgs Boson plus Jet Production
This paper presents predictions for jet pseudorapidity (eta) and transverse
momentum (p_T) distributions for the production of the Standard Model Higgs
boson in association with a high-p_T hadronic jet. We discuss the contributions
of electroweak loops and of bottom-quark parton processes to the cross section.
The latter arise in the five-flavour scheme. Predictions for the Tevatron and
the Large Hadron Collider with 10 TeV collision energy are presented. For Higgs
boson masses of 120 GeV, 160 GeV and 200 GeV, we find the maximal effects of
the electroweak contributions to the Higgs plus jet p_T and eta distribution to
be -14 % and -5.3 %, respectively, for the Tevatron, and -3 % and -2 %,
respectively, for the LHC. For the maximal contribution of bottom-quark parton
processes to the p_T and eta distribution, we find +3 % and + 2.5 %,
respectively, for the Tevatron, and +3.5 % and +3 %, respectively, for the LHC.
A separate study of the Higgs + b-jet cross section demonstrates that a
calculational approach which respects the hierarchies of Yukawa couplings
yields a leading order cross section prediction which is more accurate in the
high-p_T regime than conventional approaches.Comment: 25 pages, 14 figure
Towards a Realistic MSSM Prediction for Neutrino-nucleon Deep-inelastic Scattering
We discuss the radiative corrections to charged and neutral current
deep-inelastic neutrino--nucleon scattering in the minimal supersymmetric
standard model (MSSM). In particular, we study deviations, delta_R^nu(nu-bar),
from the Standard Model prediction for the ratios of neutral- to
charged-current cross sections, taking into account all sources for deviations
in the MSSM, i.e. different contributions from virtual Higgs bosons and virtual
superpartners. Our calculation includes the full q^2 dependence of the one-loop
amplitudes, parton distribution functions and a NuTeV-inspired process
kinematics. We present results of a scan of delta_R^nu(nu-bar) over the
relevant MSSM parameter space.Comment: 5 pages, 2 figures, to appear in Proceedings of SUSY06, the 14th
International Conference on Supersymmetry and the Unification of Fundamental
Interactions, UC Irvine, California, 12-17 June 200
Enhancement of W+/- H-/+ Production at Hadron Colliders in the Two Higgs Doublet Model
We discuss the associated W+/- H-/+ production at the CERN Large Hadron
Collider. The dependence of the hadronic cross section on the Higgs sector
parameters is investigated in detail in the framework of the general Two Higgs
Doublet Model (THDM). We study the possible enhancement of the THDM prediction
for the cross section compared to the prediction of the Minimal Supersymmetric
Standard Model (MSSM). We find regions in the THDM parameter space where the
THDM prediction can exceed the one of the MSSM by two orders of magnitude.
These regions of large cross section are in agreement with theoretical bounds
on the model, derived from the requirement of vacuum stability and perturbative
unitarity, and are not excluded by experimental constraints.Comment: 19 pages, 5 figure
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