Search for Supersymmetry Signals at the LHC

1. Search for Supersymmetry Signals at the LHC Claudia-Elisabeth Wulz Institute of High Energy Physics of the Austrian Academy of Sciences SUSY at the LHC

2. Motivation • We know that the Standard Model of particle physics must be extended • Supersymmetry is such a possible extension, which can be embedded in higher-ranking theories • Detailed predictions of experimental signatures at the TeV scale exist • Searches can be performed throughout the entire lifetime of the LHC SUSY at the LHC

3. Experiment • Data from the CMS experiment will be used. • By now more than 1 fb-1 of integrated luminosity are available.By the end of 2011 3 to 5 fb-1 are expected. • The Vienna CMS groups have particular experience in triggering, tracking, reconstruction of tracks and vertices as well as of muons, b’s and t’s. SUSY at the LHC

4. Research Goals Now • Detect deviations from the Standard Model through inclusive analyses • Contribute to determine if a signal can be SUSY or not • Identify SUSY particles and determine their parameters, measure production cross-sections and branching fractions • In parallel: optimize/develop trigger strategies for all analyses Beginning of LHC Phase 2 (≈2020) SUSY at the LHC

5. Methodology - generic signatures • Use generic signatures to detect deviations from the Standard Model • Leptonic topologies • Single lepton • Same-sign di-leptons • Opposite-sign di-leptons • Tri-leptons • Di-leptons + photon • Hadronic topologies • Exclusive n-jet • Inclusive ≥3 jet • Photon + missing ET • Current focus: search in the jets + missing ET + single muon channel • DKPI theses: • exploit jets + missing ET + single electron channel • exploit heavy flavor content of events SUSY at the LHC

6. Methodology - simplified models • Use simplified models • Example: on-shell effective theories (OSETs) • models based on bottom-up approach • templates describing particle spectra and decay chains • OSETs can be used to tune and interpret searches in a more model-independent way and to serve as interface between theory and experiment SUSY at the LHC

7. Methodology – specific searches • Use specific event signatures and models • Example: scalar top production in association with two b-jets in the coannihilation region within the Minimal Supersymmetric Standard Model, with branching fraction close to 100% • Two possible, complementary approaches: • perform cut-based analysis • use multivariate techniques SUSY at the LHC

8. Synergies within the DK • Collaboration experiment – theory • A. Hoang (University of Vienna) • Theory groups (Institute of High Energy Physics) • Development of algorithms (trigger, reconstruction, analysis) • R. Frühwirth (Institute of High Energy Physics, TU Vienna) • M. Jeitler (Institute of High Energy Physics, TU Vienna) • Experimental techniques, detector issues • M.Krammer (Institute of High Energy Physics, TU Vienna) • Computing • Austrian Tier-2 GRID centre SUSY at the LHC

9. Added value • Students will work in a stimulating environment: • investigation of fundamental physics problems • world’s most powerful particle accelerator • large scientific community but human-sized research groups • international, multidisciplinary • Focus on research activities will shift to physics analyses, after long and important development work in triggering and tracking • Reinforcement of collaboration between theorists and experimentalists SUSY at the LHC SUSY at the LHC SUSY at the LHC

10. Thank you for your attention! SUSY at the LHC