B. C. Allanach

SUSY Les Houches Accord 2

The Supersymmetry Les Houches Accord (SLHA) provides a universal set of conventions for conveying spectral and decay information for supersymmetry analysis problems in high energy physics. Here, we propose extensions of the conventions of the first SLHA to include various generalisations: the minimal supersymmetric standard model with violation of CP, R-parity, and flavour, as well as the simplest next-to-minimal model.

Benchmark models, planes, lines and points for future SUSY searches at the LHC

We define benchmark models for SUSY searches at the LHC, including the CMSSM, NUHM, mGMSB, mAMSB, MM-AMSB and p19MSSM, as well as models with R-parity violation and the NMSSM. Within the parameter spaces of these models, we propose benchmark subspaces, including planes, lines and points along them. The planes may be useful for presenting results of the experimental searches in different SUSY scenarios, while the specific benchmark points may serve for more detailed detector performance tests and comparisons. We also describe algorithms for defining suitable benchmark points along the proposed lines in the parameter spaces, and we define a few benchmark points motivated by recent fits to existing experimental data.

Searching for narrow graviton resonances with the ATLAS detector at the large hadron collider

A spectrum of massive graviton states is present in several recent theoretical models that include extra space dimensions. In some such models the graviton states are well separated in mass, and can be detected as resonances in collider experiments. The ability of the ATLAS detector at the Large Hadron Collider to identify such states and measure their properties is considered, in the case that the resonances are narrow compared to the experimental resolution. The discovery limits for the detection of the decay mode G→e+e− are derived. The angular distribution of the lepton pair is used to determine the spin of the intermediate state. In one specific model, the resonance can be detected up to a graviton resonance mass of 2080 GeV, while the angular distribution favours a spin-2 hypothesis over a spin-1 hypothesis at 90% confidence for resonance masses up to 1720 GeV.

Hide and seek with natural supersymmetry at the LHC

A bstractGluinos that result in classic large missing transverse momentum signatures at the LHC have been excluded by 2011 searches if they are lighter than around 800 GeV. This adds to the tension between experiment and supersymmetric solutions of the naturalness problem, since the gluino is required to be light if the electroweak scale is to be natural. Here, we examine natural scenarios where supersymmetry is present, but has hidden from 2011 searches due to violation of R-parity and the absence of a large missing transverse momentum signature. Naturalness suggests that third generation states should dominate gluino decays and we argue that this leads to a generic signature in the form of same-sign, flavour-ambivalent leptons, without large missing transverse momentum. As a result, searches in this channel are able to cover a broad range of scenarios with some generality and one should seek gluinos that decay in this way with masses below a TeV. We encourage the LHC experiments to tailor a search for supersymmetry in this form. We consider a specific case that is good at hiding: baryon number violation, and estimate that the most constraining existing search from 2011 data implies a lower bound on the gluino mass of 550 GeV.

Naturalness reach of the large hadron collider in minimal supergravity

We re-analyse the prospects of discovering supersymmetry at the LHC, inordertore-expresscoverageintermsofane-tuningparameterandtoextendthe analysistoscalarmasses(m0)above2TeV.Weuseminimalsupergravity(mSUGRA) unication assumptions for the SUSY breaking parameters. The discovery reach at high m0 is of renewed interest because this region has recently been found to have a focus point, leading to relatively low ne-tuning, and because it remains uncertainhowmuchoftheregioncanberuledoutduetolackofradiativeelectroweak symmetry breaking. The best ne tuning reachis foundinamono-leptonic channel, where for >0, A0 = 0 and tan = 10 (within the focus point region), and a top mass of 174GeV, all points in mSUGRA with m0 < 4000GeV, with a ne tuning measure up to 210 (500) are covered by the search, where the denition of ne-tuningexcludes(includes)thecontributionfromthetopYukawacoupling. Even forarbitrarilyhighm0,mSUGRAcanbediscoveredthroughgauginoevents,provided the gaugino mass parameter M1=2 < 460GeV. In this region, the mono-leptonic channel still provides the best reach.

Impact of CMS Multi-jets and Missing Energy Search on CMSSM Fits

Recent CMS data significantly extend the exclusion limits for supersymmetry. We examine the impact of such data on global fits of the constrained minimal super- symmetric standard model (CMSSM) to indirect and cosmological data. By simulating supersymmetric signal events at the LHC, we construct a likelihood map for the recent CMS data, validating it against the exclusion region calculated by the experiment itself. A previous CMSSM global fit is then re-weighted by our likelihood map. The CMS results nibble away at the high fit probability density region, transforming probability distribu- tions for the scalar and gluino masses. The CMS search has a non-trivial effect on tan� due to correlations between the parameters implied by the fits to indirect data.

Two Loop supersymmetric renormalization group equations including R-parity violation and aspects of unification

We present the complete 2-loop renormalization group equations of superpotential parameters for the supersymmetric standard model including the full set of R-parity violating superpotential couplings. We use these equations to do a study of (a) gauge coupling unification, (b) bottom-tau unification, (c) the fixed-point structure of the top quark Yukawa coupling, and (d) two-loop bounds from perturbative unification. The value of

The impact of the ATLAS zero-lepton, jets and missing momentum search on a CMSSM fit

{\ensuremath{\alpha}}_{S}{(M}_{Z})

Mass spectrum in R-parity violating minimal supergravity and benchmark points

predicted from unification can be reduced by 5% with respect to the R-parity conserving case, bringing it to within

Searches for new physics: Les Houches recommendations for the presentation of LHC results

2\ensuremath{\sigma}