48,018 research outputs found
A New Tool for the study of the CP-violating NMSSM
Supersymmetric extensions of the Standard Model open up the possibility for
new types of CP-violation. We consider the case of the Next-to-Minimal
Supersymmetric Standard Model where, beyond the phases from the soft
lagrangian, CP-violation could enter the Higgs sector directly at tree-level
through complex parameters in the superpotential. We develop a series of
Fortran subroutines, cast within the public tool NMSSMTools and allowing for a
phenomenological analysis of the CP-violating NMSSM. This new tool performs the
computation of the masses and couplings of the various new physics states in
this model: leading corrections to the sparticle masses are included; the
precision for the Higgs masses and couplings reaches the full one-loop and
leading two-loop order. The two-body Higgs and top decays are also attended. We
use the public tools HiggsBounds and HiggsSignals to test the Higgs sector.
Additional subroutines check the viability of the sparticle spectrum in view of
LEP-limits and constrain the phases of the model via a confrontation to the
experimentally measured Electric Dipole Moments. These tools will be made
publicly available in the near future. In this paper, we detail the workings of
our code and illustrate its use via a comparison with existing results. We also
consider some consequences of CP-violation for the NMSSM Higgs sector.Comment: 60 pages, 9 figures, updated versio
Decays of a NMSSM CP-odd Higgs in the low-mass region
A popular regime in the NMSSM parameter space involves a light CP-odd Higgs
. This scenario has consequences for e.g. light singlino Dark Matter
annihilating in the -funnel. In order to confront the pseudoscalar to
experimental limits such as flavour observables, Upsilon decays or Beam-Dump
experiments, it is necessary to control the interactions of this particle with
hadronic matter and derive the corresponding decays. The partonic description
cannot be relied upon for masses close to GeV and we employ a
chiral lagrangian, then extended to a spectator model for somewhat larger
masses, to describe the interplay of the CP-odd Higgs with hadrons.
Interestingly, a mixing can develop between and neutral pseudoscalar
mesons, leading to substantial hadronic decays and a coupling of to the
chiral anomaly. Additionally, quartic -meson couplings induce tri-meson
decays of the Higgs pseudoscalar. We investigate these effects and propose an
estimate of the Higgs widths for masses below GeV. While we focus
on the case of the NMSSM, our results are applicable to a large class of
models.Comment: 23 pages, 9 figures, published versio
Update of the flavour-physics constraints in the NMSSM
We consider the impact of several flavour-changing observables in the -
and the Kaon sectors on the parameter space of the NMSSM, in a minimal flavour
violating version of this model. Our purpose consists in updating our previous
results in arXiv:0710.3714 and designing an up-to-date flavour test for the
public package NMSSMTools. We provide details concerning our implementation of
the constraints in a series of brief reviews of the current status of the
considered channels. Finally, we present a few consequences of these flavour
constraints for the NMSSM, turning to two specific scenarios: one is
characteristic of the MSSM-limit and illustrates the workings of charged-Higgs
and genuinely supersymmetric contributions to flavour-changing processes; the
second focus is a region where a light CP-odd Higgs is present. Strong limits
are found whenever an enhancement factor - large , light ,
resonant pseudoscalar - comes into play.Comment: 22 pages, 7 figure
- …