30 likes | 142 Vues
Timothy Brooks, a Year 1 PhD student at Royal Holloway, University of London, explores the application of Boosted Decision Trees (BDT) in supersymmetry searches. The research focuses on distinguishing SU(4) mSUGRA points from background events like t-tbar and W+Z production using BDTs trained on full Monte Carlo samples. The analysis, which uses 400 trees, indicates a significant excess at 31.15 pb^-1 and investigates the effects of over-boosting and background uncertainties. Further studies aim to refine signal extraction in di-lepton and jet multiplicity channels.
E N D
Boosted Decision Trees for Supersymmetry Searches Timothy Brooks Year 1 PhD Student Royal Holloway University of London
Boosted Decision TreeSeparation SU4 mSUGRA Point Backgrounds considered: Ttbar production W+Z production Comparisons made to Multi-lepton cuts. Precut requires NLeptons >= 3 Trained on full MC sample (without cuts) to maximise training sample. 400 trees used here. s = 63.4 b = 32.8 Z = 8.96
Boosted Decision TreeSignificance 5 σ excess at 31.15 pb-1 Effect of over boosting investigated. Significance estimation needs to include background uncertainties. Need to move to Di-lepton + 4 jet analysis. Aim is to investigate if a BDT run on control and expected signal regions can extract the top component in the signal region. To recover higher statistics, channels with jet multiplicities lower than 4 will be investigated.