9 research outputs found
SFOLD - a program package for calculating two-body sfermion decays at full one-loop level in the MSSM
SFOLD (Sfermion Full One Loop Decays) is a Fortran program package for
calculating all sfermion two-body decay widths and the corresponding branching
ratios at full one-loop level within the MSSM. The package adopts the SUSY
Parameter Analysis convention and supports the SUSY Les Houches Accord input
and output format. With the SFOLD package we found non-negligible electroweak
corrections in bosonic decays of sbottom, stop and stau.Comment: 17 pages, 3 figure
Heavy Higgs decays into sfermions in the complex MSSM: a full one-loop analysis
For the search for additional Higgs bosons in the Minimal Supersymmetric Standard Model (MSSM) as well as for future precision analyses in the Higgs sector a precise knowledge of their decay properties is mandatory. We evaluate all two-body decay modes of the heavy Higgs bosons into sfermions in the MSSM with complex parameters (cMSSM). The evaluation is based on a full one-loop calculation of all decay channels, also including hard QED and QCD radiation. The dependence of the heavy Higgs bosons on the relevant cMSSM parameters is analyzed numerically. We find sizable contributions to many partial decay widths. They are roughly of O(15%) of the tree-level results, but can go up to 30% or higher. The size of the electroweak one-loop corrections can be as large as the QCD corrections. The full one-loop contributions are important for the correct interpretation of heavy Higgs-boson search results at the LHC and, if kinematically allowed, at a future linear e+e- collider. The evaluation of the branching ratios of the heavy Higgs bosons will be implemented into the Fortran code FeynHiggs
FlexibleDecay: An automated calculator of scalar decay widths
We present FlexibleDecay, a tool to calculate decays of scalars in a broad
class of BSM models. The tool aims for high precision particularly in the case
of Higgs boson decays. In the case of scalar and pseudoscalar Higgs boson
decays the known higher order SM QED, QCD and EW effects are taken into account
where possible. The program works in a modified scheme that
exhibits a decoupling property with respect to heavy BSM physics, with BSM
parameters themselves treated in the -scheme
allowing for an easy connection to high scale tests for, e.g., perturbativity
and vacuum stability, and the many observable calculations readily available in
programs. Pure BSM effects are taken into
account at the leading order, including all one-loop contributions to
loop-induced processes. The program is implemented as an extension to
FlexibleSUSY, which determines the mass spectrum for arbitrary BSM models, and
does not require any extra configuration from the user. We compare our
predictions for Higgs decays in the SM, singlet extended SM, type II THDM,
CMSSM and MRSSM, as well as for squark decays in the CMSSM against a selection
of publicly available tools. The numerical differences between our and other
programs are explained. The release of FlexibleDecay officially deprecates the
old effective couplings routines in FlexibleSUSY.Comment: 44 pages, 3 figures, 11 tables; version published in CP
Computing decay rates for new physics theories with FeynRules and MadGraph5/aMC@NLO
We present new features of the FeynRules and MadGraph5/aMC@NLO programs for
the automatic computation of decay widths that consistently include channels of
arbitrary final-state multiplicity. The implementations are generic enough so
that they can be used in the framework of any quantum field theory, possibly
including higher-dimensional operators. We extend at the same time the
conventions of the Universal FeynRules Output (or UFO) format to include decay
tables and information on the total widths. We finally provide a set of
representative examples of the usage of the new functions of the different
codes in the framework of the Standard Model, the Higgs Effective Field Theory,
the Strongly Interacting Light Higgs model and the Minimal Supersymmetric
Standard Model and compare the results to available literature and programs for
validation purposes.Comment: 32 pages, 2 figures. Published versio
Computing decay rates for new physics theories with FeynRules and MadGraph 5_aMC@NLO
We present new features of the FeynRules and MadGraph 5_aMC@NLO programs for the automatic computation of decay widths that consistently include channels of arbitrary final-state multiplicity. The implementations are generic enough so that they can be used in the framework of any quantum field theory, possibly including higher-dimensional operators. We extend at the same time the conventions of the Universal FeynRules Output (or UFO) format to include decay tables and information on the total widths. We finally provide a set of representative examples of the usage of the new functions of the different codes in the framework of the Standard Model, the Higgs Effective Field Theory, the Strongly Interacting Light Higgs model and the Minimal Supersymmetric Standard Model and compare the results to available literature and programs for validation purposes
Precision tools and models to narrow in on the 750 GeV diphoton resonance
The hints for a new resonance at 750 GeV from ATLAS and CMS have triggered a
significant amount of attention. Since the simplest extensions of the standard
model cannot accommodate the observation, many alternatives have been
considered to explain the excess. Here we focus on several proposed
renormalisable weakly-coupled models and revisit results given in the
literature. We point out that physically important subtleties are often missed
or neglected. To facilitate the study of the excess we have created a
collection of 40 model files, selected from recent literature, for the
Mathematica package SARAH. With SARAH one can generate files to perform
numerical studies using the tailor-made spectrum generators FlexibleSUSY and
SPheno. These have been extended to automatically include crucial higher order
corrections to the diphoton and digluon decay rates for both CP-even and CP-odd
scalars. Additionally, we have extended the UFO and CalcHep interfaces of
SARAH, to pass the precise information about the effective vertices from the
spectrum generator to a Monte-Carlo tool. Finally, as an example to demonstrate
the power of the entire setup, we present a new supersymmetric model that
accommodates the diphoton excess, explicitly demonstrating how a large width
can be obtained. We explicitly show several steps in detail to elucidate the
use of these public tools in the precision study of this model.Comment: 184 pages, 24 figures; model files available at
http://sarah.hepforge.org/Diphoton_Models.tar.gz; v2: added a few
clarifications and reference