BMSSM Higgses at 125 GeV

The BMSSM framework is an effective theory approach that encapsulates a variety of extensions beyond the MSSM with which it shares the same field content. The lightest Higgs mass can be much heavier than in the MSSM without creating a tension with naturalness or requiring superheavy stops. The phenomenology of the Higgs sector is at the same time much richer. We critically review the properties of a Higgs with mass around 125GeV in this model. In particular, we investigate how the rates in the important inclusive 2 photons channel, the 2 photons + 2 jets and the ZZ to 4 leptons (and/or WW) can be enhanced or reduced compared to the standard model and what kind of correlations between these rates are possible. We consider both a vanilla model where stops have moderate masses and do not mix and a model with large mixing and a light stop. We show that in both cases there are scenarios that lead to enhancements in these rates at a mass of 125GeV corresponding either to the lightest Higgs or the heaviest CP-even Higgs of the model. In all of these scenarios we study the prospects of finding other signatures either of the 125GeV Higgs or those of the heavier Higgses. In most cases the \oo{\tau}\tau channels are the most promising. Exclusion limits from the recent LHC Higgs searches are folded in our analyses while the tantalising hints for a Higgs signal at 125GeV are used as an example of how to constrain the BMSSM and/or direct future searches.Comment: 21 p v1 Tevatron result added in addendum, typo

SUSY Tools for Dark Matter and at the Colliders

With present and upcoming SUSY searches both directly, indirectly and at accelerators, the need for accurate calculations is large. We will here go through some of the tools available both from a dark matter point of view and at accelerators. For natural reasons, we will focus on public tools, even though there are some rather sophisticated private tools as well.Comment: 20 pages, 4 figures, Chapter 16 of the book "Particle Dark Matter: Observations, Models and Searches" edited by G. Bertone, Cambridge University Press, http://cambridge.org/us/catalogue/catalogue.asp?isbn=978052176368

Tools for Dark Matter in Particle and Astroparticle Physics

Despite several indirect confirmations of the existence of dark matter, the properties of a new dark matter particle are still largely unknown. Several experiments are currently searching for this particle underground in direct detection, in space and on earth in indirect detection and at the LHC. A confirmed signal could select a model for dark matter among the many extensions of the standard model. In this paper we present a short review of the public codes for computation of dark matter observables.Comment: 10 pages, 2 figures, to appear in the Proceedings of 13th International Workshop on Advanced Computing and Analysis Techniques in Physics Research, February 2010, Jaipur, Indi

Leading Yukawa corrections to Higgs production associated with a tagged bottom anti-bottom pair in the Standard Model at the LHC

Considering the large value of the top Yukawa coupling, we investigate the leading one-loop Yukawa electroweak corrections that can be induced by the top quark in a process such as Higgs production in association with a tagged bottom anti-bottom pair at the LHC. At NLO these contributions are found to be small at the LHC both for the total cross section and for the distributions. In the limit of vanishing bottom Yukawa coupling where the LO contribution vanishes, the process can still be induced at one-loop through the top quark transition. Though this contribution which can be counted as part of the NNLO correction is small for Higgs masses around 120GeV, it quickly picks up for higher Higgs masses. This contribution represents the rescattering of the top quarks and their decay into W's leading to Higgs production through WW fusionComment: 23 pages, 9 figures. One reference added (or rather corrected). Text unchange

NLO corrections to WWZ and ZZZ production at the ILC

We calculate the full one-loop electroweak corrections to tri-boson production (ZZZ and WWZ) at the ILC. This is important to understand the Standard Model (SM) gauge quartic couplings which can be a window on the mechanism of spontaneous symmetry breaking. We find that even after subtracting the leading QED corrections, the electroweak corrections can still be large especially as the energy increases.Comment: 7 pages, proceedings of the 3rd CPP Workshop, September 23-25, 2010, KEK Tsukuba Japa

Lab-frame observables for probing the top-Higgs interaction

We investigate methods to explore the CP nature of the $t\bar{t}h$ coupling at the LHC, focusing on associated production of the Higgs with a $t \bar{t}$ pair. We first discuss the constraints implied by low-energy observables and by the Higgs-rate information from available LHC data, emphasizing that they cannot provide conclusive evidence on the nature of this coupling. We then investigate kinematic observables that could probe the $t\bar{t}h$ coupling directly, in particular quantities that can be constructed out of just lab-frame kinematics. We define one such observable by exploiting the fact that $t \bar{t}$ spin correlations do also carry information about the CP-nature of the $t\bar{t}h$ coupling. Finally, we introduce a CP-odd quantity and a related asymmetry, able to probe CP violation in the $t\bar{t}h$ coupling and likewise constructed out of lab-frame momenta only.Comment: 32 pages, updated with latest data from ATLAS and references adde

SUSY Dark Matter: Loops and Precision from Particle Physics

With cosmology entering the era of precision measurements, the synergy with particle physics has strengthened. This new level of precision requires that the dark matter cross sections need to be evaluated with better accuracy at the loop level. We report on the progress in building the automatic code SloopS for generic one-loop calculations in supersymmetry that is applicable for collider observables, the relic density and indirect detection

NLO corrections to e+e- to WWZ and e+e- to ZZZ

We calculate the one-loop electroweak corrections to e+e- to WWZ and e+e- to ZZZ and analyse their impacts on both the total cross section and some key distributions. These processes are important for the measurements of the quartic couplings of the massive gauge bosons which can be a window on the mechanism of spontaneous symmetry breaking. We find that even after subtracting the leading QED corrections, the electroweak corrections can still be large especially as the energy increases. We compare and implement different methods of dealing with potential instabilities in the routines pertaining to the loop integrals. For the real corrections we apply a dipole subtraction formalism and compare it to a phase-space slicing method.Comment: 19 pages, a few comments and references added, version published in PRD