REPORT ON THE LYON WORKSHOP BLIND SUSY ANALYSIS REPORT ON THE LYON WORKSHOP OUTLINE Introduction Updates First public results Conclusions and Outlook 1 S. Muanza, CPPM Marseille 1

Introduction - Reminders - The « SUSY Blind Analysis » is a SUSY challenge that was coocked ~2 years ago in the SUSY GDR and proposed to SUSY hunters communities (LH 2007) The aim was to test our methods and strategies to: assess a SUSY signal at the LHC measure some observables (end-points, thresholds, s, BR ratios,…) constrain or determine the underlying model parameters all of this in a BLIND ANALYSIS 2 2

Introduction - Cookbook - A SUSY point was chosen in a model to be determined All the SUSY & Higgs processes were produced simultaneously and mixed with the SM background (MC truth infos removed) CoM energy: 14 TeV, L=100 pb-1 Individual SM background samples were also made available Format: simple root-tuples available at CCIN2P3 in HPSS, also made available elsewhere using SRB Website: http://www-clued0.fnal.gov/~muanza/Blind_SUSY_Analysis.html 3 3

Introduction - Lyon Workshop - Very few people dared to try & solve this SUSY challenge The Lyon workshop was proposed to revive this project within the GDR and to make myself available to answer any technical questions while some analyzers were actually « getting their hands dirty » with the challenge Place: IPN Lyon Date: 25-27 march 2009 Low attendance: 2 post-docs from Lyon => very informal workshop 3 people based at CERN expressed interest but finally did not have time to try the challenge at the time of the workshop 4 4

Updates - Technicalities - At CCIN2P3 the Linux platforms have evolved: at the time I produced the samples: ROOT v5.14, SL v3, gcc v3.2.3, 32-bits currently: ROOT v5.14, SL v4, gcc v3.4.6, 64-bits platform (supports 32-bits) h2root does not work anymore! solution connect to ccalisl432.in2p3.fr : works interactively no batch support for 32-bits code 5 5

Updates - Revealing a Clue - Here’s the main experimental trick I introduced to differentiate the pseudo-data sample from the SM background samples: PsD1: was produced using the option KEYLUM=2 (high lumi) BKGD: was produced using the option KEYLUM=1 (low lumi) effects: I chose not to change the trigger nor the jets thresholds the only effects are different resolutions can find it in the code (tarball on the webpage): atlfast-00-02-22/atlfast/atlfast.F FUNCTIONS: RESHAD, RESEL, RESPHO 6 6

Updates - Revealing a Clue - This is propagate to the mET calculation: SUBROUTINE: MAKMIS Example: Jet Resolutions |h|<3.0: |h|>3.0: for DR=0.4, Epile-up=7.5 GeV 7 7

Updates - New Analysis Code - I updated the proposed analysis code: a bug fix on a Z(qq)+jets cross section (thanks to Patrice Verdier) slightly different access to the sub-processes root-tuples: each sub-process in its own sub-dir the analysis code automatically makes TChain w/ all the root-tuples in there it does not depend on a specific root-tuple name anymore the user will have to copy the sub-dir tree in his/her working area the code is set to analyze the skimmed (mET > 150 GeV) root-tuples the code can perform further skimmings 8 8

Updates - New Analysis Code: Outputs - Arbitrary Cuts: Trigger OR mET > 250 GeV Njets > 3 9 9

First Public Results - P. Verdier - 10 10

Conclusions & Outlook Apologies I did not find the time to update the website (end of this week) I encourage all of you to try this SUSY challenge Especially to measure some features of the SUSY+Higgs excess And to hand it over to SUSY fitters (Sfitter, Fittino, OSET methods,…) I’ll « open the box » at the time of the Les Houches 2009 meeting And give the bottle champagne to the author of the closest answer! 11 11