Discrepancies between measurements of decay modes with an underlying quark level transition $$b\rightarrow s \ell ^+\ell ^-$$ <math><mrow><mi>b</mi><mo>→</mo><mi>s</mi><msup><mi>ℓ</mi><mo>+</mo></msup><msup><mi>ℓ</mi><mo>-</mo></msup></mrow></math>  and standard model (SM) predictions have persisted for several years, particularly for the muon channels. The inadequacy of the SM becomes more compelling in a global fit. For example, Capdevila et al. (JHEP 01, 093. arXiv:1704.05340, 2018) described 175 observables by six parameters encoding new physics and quantified the disagreement with the SM at about the $$5\sigma $$ <math><mrow><mn>5</mn><mi>σ</mi></mrow></math>  level. While certain one and two parameter fits have previously been considered in detail, we establish a framework for the detailed discussion of the full 6d fit. We visualize and quantify the 6d $$1\sigma $$ <math><mrow><mn>1</mn><mi>σ</mi></mrow></math>  region around the best fit point and define fit uncertainties for both current and future observables. We then define metrics quantifying the deviations between measurements and both SM and best fit predictions. These metrics relate observables to directions in parameter space, revealing their precise role in the fit, thus providing guidance for future theoretical and experimental work. Some metrics further quantify the role of correlated uncertainties, which turns out to be significant. For example the relevance of angular observables such as $$P_5^\prime $$ <math><msubsup><mi>P</mi><mn>5</mn><mo>′</mo></msubsup></math>  is reduced in this context. Finally, studying the space of observables allows us to discuss the internal tensions in the fit.

Spain

Bernat Capdevila

Australia

Ursula Laa

German Valencia

Anatomy of a six-parameter fit to the $$b\rightarrow s \ell ^+\ell ^-$$ <math><mrow><mi>b</mi><mo>→</mo><mi>s</mi><msup><mi>ℓ</mi><mo>+</mo></msup><msup><mi>ℓ</mi><mo>-</mo></msup></mrow></math>  anomalies

A recent paper on visualizing the sensitivity of hadronic experiments to nucleon structure (Wang et al. in arXiv:1803.02777, 2018) introduces the tool PDFSense which defines measures to allow the user to judge the sensitivity of PDF fits to a given experiment. The sensitivity is characterized by high-dimensional data residuals that are visualized in a 3-d subspace of the 10 first principal components or using non-linear embeddings. We show how a tour, a dynamic visualisation of high dimensional data, can extend this tool beyond 3-d relationships. This approach enables resolving structure orthogonal to the 2-d viewing plane used so far, and hence finer tuned assessment of the sensitivity.

Dianne Cook

Dynamical projections for the visualization of PDFSense data

We investigate to which extent the SUSY search results published by ATLAS and CMS in the context of simplified models actually cover the more realistic scenarios of a full model. Concretely, we work within the phenomenological MSSM (pMSSM) with 19 free parameters and compare the constraints obtained from SModelS Â v1.1.1 with those from the ATLAS pMSSM study in arXiv:1508.06608 . We find that about 40â45% of the points excluded by ATLAS escape the currently available simplified model constraints. For these points we identify the most relevant topologies which are not tested by the current simplified model results. In particular, we find that topologies with asymmetric branches, including 3-jet signatures from gluinoâsquark associated production, could be important for improving the current constraining power of simplified models results. Furthermore, for a better coverage of light stops and sbottoms, constraints for decays via heavier neutralinos and charginos, which subsequently decay visibly to the lightest neutralino are also needed.

Austria

Federico Ambrogi

France

Sabine Kraml

Suchita Kulkarni

Brazil

Andre Lessa

Wolfgang Waltenberger

On the coverage of the pMSSM by simplified model results

We consider simplified dark matter models where a dark matter candidate couples to the standard model (SM) particles via an s -channel spin-2 mediator, and study constraints on the model parameter space from the current LHC data. Our focus lies on the complementarity among different searches, in particular monojet and multijet plus missing-energy searches and resonance searches. For universal couplings of the mediator to SM particles, missing-energy searches can give stronger constraints than WW , ZZ , dijet, dihiggs, tt¯ , bb¯ resonance searches in the low-mass region and/or when the coupling of the mediator to dark matter is much larger than its couplings to SM particles. The strongest constraints, however, come from diphoton and dilepton resonance searches. Only if these modes are suppressed, missing-energy searches can be competitive in constraining dark matter models with a spin-2 mediator.

Belgium

Kentarou Mawatari

Japan

Kimiko Yamashita

Simplified dark matter models with a spin-2 mediator at the LHC

We assess how different ATLAS and CMS searches for supersymmetry in the t t ¯ + E T miss $$ t\overline{t}+{E}_T^{\mathrm{miss}} $$ final state at Run 1 of the LHC constrain scenarios with a fermionic top partner and a dark matter candidate. We find that the efficiencies of these searches in all-hadronic, 1-lepton and 2-lepton channels are quite similar for scalar and fermionic top partners. Therefore, in general, efficiency maps for stop-neutralino simplified models can also be applied to fermionic top-partner models, provided the narrow width approximation holds in the latter. Owing to the much higher production cross-sections of heavy top quarks as compared to stops, masses up to m T ≈ 850 GeV can be excluded from the Run 1 stop searches. Since the simplified-model results published by ATLAS and CMS do not extend to such high masses, we provide our own efficiency maps obtained with C heck MATE and M ad A nalysis 5 for these searches. Finally, we also discuss how generic gluino/squark searches in multi-jet final states constrain heavy top partner production.

United Kingdom

Luca Panizzi

Hugo Prager

Scalar versus fermionic top partner interpretations of t t ¯ + E T miss $$ t\overline{t}+{E}_T^{\mathrm{miss}} $$ searches at the LHC

A mostly right-handed sneutrino as the lightest supersymmetric particle (LSP) is an interesting dark matter candidate, leading to LHC signatures which can be quite distinct from those of the conventional neutralino LSP. Using SModelS v1.0.1 for testing the model against the limits published by ATLAS and CMS in the context of so-called Simplified Model Spectra (SMS), we investigate to what extent the supersymmetry searches at Run 1 of the LHC constrain the sneutrino-LSP scenario. Moreover, we discuss the most relevant topologies for which no SMS results are provided by the experimental collaborations but which would allow to put more stringent constraints on sneutrino LSPs. These include, for instance, the mono-lepton signature which should be particularly interesting to consider at Run 2 of the LHC.

Netherlands

Chiara Arina

Maria Catalan

Constraints on sneutrino dark matter from LHC Run 1

We present a general procedure to decompose Beyond the Standard Model (BSM) collider signatures presenting a Z2 symmetry into Simplified Model Spectrum (SMS) topologies. Our method provides a way to cast BSM predictions for the LHC in a model independent framework, which can be directly confronted with the relevant experimental constraints. Our concrete implementation currently focusses on supersymmetry searches with missing energy, for which a large variety of SMS results from ATLAS and CMS are available. As show-case examples we apply our procedure to two scans of the minimal supersymmetric standard model. We discuss how the SMS limits constrain various particle masses and which regions of parameter space remain unchallenged by the current SMS interpretations of the LHC results.

Wolfgang Magerl

Doris Proschofsky-Spindler

SModelS: a tool for interpreting simplified-model results from the LHC and its application to supersymmetry