Mark D. Goodsell

Precision tools and models to narrow in on the 750 GeV diphoton resonance

The hints for a new resonance at 750xa0GeV 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.

Two-loop Higgs mass calculations in supersymmetric models beyond the MSSM with SARAH and SPheno

We present an extension to the Mathematica package SARAH which allows for Higgs mass calculations at the two-loop level in a wide range of supersymmetric (SUSY) models beyond the MSSM. These calculations are based on the effective potential approach and include all two-loop corrections which are independent of electroweak gauge couplings. For the numerical evaluation Fortran code for SPheno is generated by SARAH. This allows the prediction of the Higgs mass in more complicated SUSY models with the same precision that most state-of-the-art spectrum generators provide for the MSSM.

Dirac gauginos and kinetic mixing

We present formulae for the calculation of Dirac gaugino masses at leading order in the supersymmetry breaking scale using the methods of analytic continuation in superspace and demonstrate a link with kinetic mixing, even for non-abelian gauginos. We illustrate the result through examples in field and string theory. We discuss the possibility that the singlet superfield that gives the U(1) gaugino a Dirac mass may be a modulus, and some consequences of the D-term coupling to the scalar component. We give examples of possible effects in colliders and astroparticle experiments if the modulus scalar constitutes decaying dark matter.

Generating μ and Bμ in models with Dirac gauginos

We consider the extension of the Minimal Supersymmetric Standard Model by Dirac masses for the gauginos. We study the possibility that the same singlet S that pairs up with the bino. to form a Dirac fermion, is used to generate it and Bit terms through its vacuum expectation value. For this purpose. we assume that, in the Higgs potential. the necessary R-symmetry breaking originates entirely from a superpotential term (kappa)/S-3(3) and discuss the implications for the spectrum of the model

Two-loop corrections to the Higgs masses in the NMSSM

We discuss the impact of the two-loop corrections to the Higgs mass in the NMSSM beyond

Flavour models with Dirac and fake gluinos

O(alpha_S(alpha_b + alpha_t))

Constrained minimal Dirac gaugino supersymmetric standard model

. For this purpose we use the combination of the public tools SARAH and SPheno to include all contributions stemming from superpotential parameters. We show that the corrections in the case of a heavy singlet are often MSSM-like and reduce the predicted mass of the SM-like state by about 1 GeV as long as

Dirac gauginos in low scale supersymmetry breaking

lambda

Dark matter scenarios in a constrained model with Dirac gauginos

is moderately large. For larger values of

A fake split-supersymmetry model for the 126 GeV Higgs

lambda