Search for SUperSYmmetry (SUSY) in Opposite Sign (OS) di-lepton final states with Parked Data collected at $\sqrt{s}$ = 8 TeV using the CMS detector

The Large Hadron Collider (LHC) has had a very successful data-taking phase with Run 1. After the discovery of the Higgs, confirming the predictions of the Standard Model (SM), the focus is on finding new physics, especially in the context of supersymmetry (SUSY). One of the potential hiding places of natural SUSY is in models with compressed spectra, that is, models where the mass difference between the parent SUSY particle and the Lightest Supersymmetric Particle (LSP) is small. Such signals are characterized by low transverse momentum (p${_T}$) objects, low hadronic activity and missing transverse energy (MET). In this analysis, we focus on di-lepton final states, specifically in the low p${_T}$ regime. We use 7.4 fb$^{-1}$ of parked data collected at $\sqrt{s}$ = 8 TeV. The analysis is enabled by the use of triggers that place no restrictions on the di-lepton p${_T}$, instead relying on methods like Initial State Radiation (ISR) tagging by triggering on a high p${_T}$ photon, to reduce the trigger rate. The final state we are interested in consists of a high p${_T}$ photon and two oppositely charged leptons. Since no statistically significant excess of events consistent with the presence of supersymmetric particles was found, we compute exclusion limits at a 95\% confidence level for the cross section of stop pair production in association with a photon. We also show results for model independent limits in this channel.