Supersymmetry with heavy scalars at the LHC

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Tezin Türü: Doktora

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Fen Edebiyat Fakültesi, Fizik Bölümü, Türkiye

Tezin Onay Tarihi: 2008

Öğrenci: SEZEN SEKMEN

Danışman: MEHMET TEVFİK ZEYREK

Özet:

We consider three distinct categories of supersymmetric scenarios with heavy scalars and light gauginos. First, we investigate the SO(10) SUSY GUTs, and locate MSSM parameter space regions that satisfy GUT scale Yukawa unification, which is a distinct feature of these models. Then taking example SO(10) cases, we perform a Monte Carlo study with toy detector simulation at 14 TeV at the LHC on the no $\met$ leptonic channels 2,3 leptons + $\ge$4 jets and show that discovery is possible with $\sim$1 fb$^{-1}$ of integrated luminosity. We also demonstrate the feasibility of invariant mass endpoint measurements for $\sim$100 fb$^{-1}$. Furthermore, in a cosmological context, we propose that SO(10) scenarios with excess neutralino relic abundance can be made WMAP-compatble by assuming neutralino decays to axinos, and show that there are various axino/axion cold and warm dark matter admixtures which can be consistent with non-thermal leptogenesis requirements for the thermal re-heat temperature. Afterwards we complement the SO(10)s with the string-inspired G$_2$-MSSM and focus point mSUGRA scenarios and perform a full simulation search of these at $\sqrt{s} =$ 14 TeV at the LHC with the CMS detector where the main production mechanism is through gluino pair production and the final states are cheracterized by all-hadronic topologies (including $b$s and $t$s). Through the design of six prototype all-hadronic selection paths and using the CMS High Lever Trigger paths with highest significance (including the $b$-enriched ones), we find that all but one model benchmarks are accessible with 100 pb$^{-1}$ integrated luminosity. We present the results as a function of the gluino mass considering the major detector systematic effects.