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Supersymmetry Content 퐵푢푔푟푎 푌푖푙푑푖푧∗ Supersymmetry Content Introduction (SUSY) Motivation (SUSY) Stop Squark Analysis Samples Cuts Histograms Conclusion 6 July 2015 Bugra Yildiz 2 Introduction SUSY is a proposed type of spacetime symmetry that relates bosons and fermions. Each particle from one group is associated with a particle from the other, known as its superpartner, the spin of which differs by a half-integer. If supersymmetry exists then it must be a spontaneously broken symmetry. 6 July 2015 Bugra Yildiz 3 Motivation There are three principal motivations Naturalness : Radiative corrections are quadratically divergent in the Standard Model (hierarchy problem). 6 July 2015 Bugra Yildiz 4 Gauge coupling unifications : If the superpartners of the Standard Model are near the TeV scale, then measured gauge couplings of the three gauge groups unify at high energies. Dark matter : If R-parity is preserved, then the lightest superparticle (LSP) of the MSSM is stable and is a Weakly interacting massive particle (WIMP). 6 July 2015 Bugra Yildiz 5 Stop Stop squark is the superpartner of the top quark. It is a spin-0 boson (scalar). The top quark is the heaviest known quark, the stop squark is actually often the lightest squark in many supersymmetry models. 6 July 2015 Bugra Yildiz 6 The stop is a key ingredient of a wide range of SUSY models that address the hierarchy problem of the Standard Model (SM) in a natural way.It would stabilize the Higgs boson mass against quadratically divergent quantum corrections, provided its mass is close to the electroweak symmetry breaking energy scale (246 GeV). If this was the case then the stop would be accessible at the Large Hadron Collider. 6 July 2015 Bugra Yildiz 7 Depending on the specific details of the SUSY model and the mass hierarchy of the sparticles, the stop might decay into a bottom quark and a chargino, with a subsequent decay of the chargino into the lightest neutralino. Lepton Bottom Quark Neutrino Stop Neutrolino Chargino 6 July 2015 Bugra Yildiz 8 Analysis Aim : We have to synchronize ourselves with single lepton stop analysis group. Software : CMGTools Samples : EOS /store/cmst3/group/susy/Phys14_V3/ 6 July 2015 Bugra Yildiz 9 Sample Used : T1tttt_HL_1500_100 4 Top Quark Gluino Mass : 1500 GeV Neutralino Mass : 100 GeV High Gluino Mass wrt Low Neutralino Mass 6 July 2015 Bugra Yildiz 10 Cuts 0. No Cuts 1. 1 Lepton Cut 2. Lepton Veto 3. Njets ≥ 2 4. Njets ≥ 4 5. Leading jets pT > 80 unused 6. HT > 750 7. MET > 80 8. NbJet ≥ 1 6 July 2015 Bugra Yildiz 11 Cut Flow 6 July 2015 Bugra Yildiz 12 6 July 2015 Bugra Yildiz 13 6 July 2015 Bugra Yildiz 14 6 July 2015 Bugra Yildiz 15 6 July 2015 Bugra Yildiz 16 6 July 2015 Bugra Yildiz 17 6 July 2015 Bugra Yildiz 18 6 July 2015 Bugra Yildiz 19 6 July 2015 Bugra Yildiz 20 6 July 2015 Bugra Yildiz 21 6 July 2015 Bugra Yildiz 22 6 July 2015 Bugra Yildiz 23 6 July 2015 Bugra Yildiz 24 6 July 2015 Bugra Yildiz 25 6 July 2015 Bugra Yildiz 26 6 July 2015 Bugra Yildiz 27 6 July 2015 Bugra Yildiz 28 6 July 2015 Bugra Yildiz 29 6 July 2015 Bugra Yildiz 30 Conclusion • I analyzed T1tttt_HL_1500_100 sample, applied the different cuts and checked the results. (https://twiki.cern.ch/twiki/bin/viewauth/CMS/ ACDSUSYSingleLepton) • Preparation for 13 TeV stop 1l analysis is continiue. (https://twiki.cern.ch/twiki/bin/view/CMS/Stop SingleLepton2015#Common_Baby_Format) 6 July 2015 Bugra Yildiz 31 Thanks ∗ This work has been supported by Hacettepe University, Scientific Research Projects Program through the Project: 014 A602 004-824. 6 July 2015 Bugra Yildiz 32.
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