1. Ignacio Suárez Andrés Universidad de Oviedo XXXV Bienal de la RSEF 13/07/2015

2. Content Motivation CMS experiment Boosted Decision Trees Analysis and results 2

3. 3

4. Standard Model and BSM (SUSY) 4

5. Strongest coupling to Higgs field Determination of PDFs Top coupling to W/Z: vector and axial components 6D operators in BSM Multileptonic searches Backgrounds for: 5

6. This is all motivation to... 6

7. 7

8. CMS (Compact Muon Solenoid) 8

9. 9

10. Why BDTs? Easy to understand and explain Satisfactory BDT obtainable with little tuning Intuitive parameters Irrelevant variables are ignored Short computation time Compare all of this to Artificial Neural Networks… 10

11. Decision trees Separation: Gini index 11

12. Boosting: AdaBoost Steps: Train (preferably small) tree Give larger weights to misclassified events Train new tree … Combine weighted results 12

13. Output Implementation : package for Result: separation! 13

14. 14

15. Selection and variables 15 S IP of 2nd track

16. Two methods 1) Cut: Instead of sequential analysis, cut on BDT output, selecting signal-rich region 2) Fit: Since shape of BDT output is greatly influenced by signal events, rescale signal MC to fit data 16

17. Cut Fit Sergio Sánchez & Santiago Folgueras ongoing 17

18. Cut Fit CMS-TOP-14-021 SS+3L ongoing 18

19. Cut Fit CMS-TOP-14-021 OS+3L+4L ongoing 19

20. Conclusions 20