SUSY search prospects with 1 fb-1 data Rasmus Mackeprang (rasmack@nbi.dk) Discovery, center for particle physics On behalf of the CMS and ATLAS collaborations Ann Arbor - Dec 14, 2010

SUSY search prospects with 1fb-1 data You are aware that Supersymmetry postulates “superpartners” to the SM particles This regularises the higgs mass R-parity is introduced to keep the proton stable: R = (-1)2j+3B+L Breaking R-parity “just a little” gives an even richer phenomenology Cascade decays Long-lived particles Ann Arbor - Dec 14, 2010

You furthermore understand that SUSY search prospects with 1fb-1 data You furthermore understand that Two general-purpose experiments are operating at the LHC Differently sized physicists silicon det. (pixel, strips) 4T solenoid magnet crystal EM calorimeter σ(E)/E~3%/√E+0.003 brass/scintillator had. Calorimeter σ(E)/E~100%/√E+0.05 muon chambers σ(p)/p<10% at 1TeV silicon det. (pixel, strips) +TRT 2T solenoid + toroid magnets LAr EM calorimeter σ(E)/E~10%/√E+0.007 steel/scintillator had. calorimeter σ(E)/E~50%/√E+0.03 muon chambers σ(p)/p<10% at 1TeV Ann Arbor - Dec 14, 2010

Taking a step back… LHC Tevatron SUSY search prospects with 1fb-1 data Taking a step back… LHC Tevatron arXiv:1007.3492 So, the SM seems best left to the Tevatron for the next year Huge inroads exist into BSM physics, though Orders of magnitude to be found in some production cross sections Ann Arbor - Dec 14, 2010

SUSY is a broad concept… SUSY search prospects with 1fb-1 data SUSY is a broad concept… The MSSM contains a mere 120 parameters Not-so-minimal models even more Parameterized classes of theories based on physics assumptions introduce dependencies between parameters (e.g. mSUGRA, GMSB, AMSB…) One can construct (theoretically well motivated) models that fall outside the phenomenologies spanned by these models Do model-independent searches for generic signatures that can be discerned from the SM In preparation, scan parameter spaces of the different theories All these people… Looking for me? Ann Arbor - Dec 14, 2010

A typical day at the LHC… SUSY search prospects with 1fb-1 data A typical day at the LHC… 2 b-jets 2 jets 1 lepton Missing ET LHS-2 SPS 1a Lepton reconstruction and identification Jet reconstruction (and energy scale) Missing ET Ann Arbor - Dec 14, 2010

Missing transverse energy is traditionally hard… SUSY search prospects with 1fb-1 data Missing transverse energy is traditionally hard… Stick in non-minbias ATLAS-CONF-2010-057 CMS-PAS-JME-10-004 CMS-PAS-JME-10-005 Ann Arbor - Dec 14, 2010

Beating Back the Background SUSY search prospects with 1fb-1 data Beating Back the Background = 0.5 for a well-reconstructed QCD event One central jet (|η|<2) Two jets over 100 GeV 10 TeV study Cut on fraction of missing transverse jet momentum carried by soft jets HT: Scalar sum of transverse jet momenta MET cut is on Jet MET only Ann Arbor - Dec 14, 2010 CMS PAS SUS-09-001

General strategies Look for 1, 2, 3, 4 lepton events (+ jets + MET) SUSY search prospects with 1fb-1 data General strategies Look for 1, 2, 3, 4 lepton events (+ jets + MET) Peaks Edges All-hadronic channels Normalizations Search for stable massive particles Monojet signatures Anomalous energy depositions Out of time Stopping in the detector and decaying later Ann Arbor - Dec 14, 2010

Got to start somewhere SU4 (mSUGRA) SUSY search prospects with 1fb-1 data Got to start somewhere SU4 (mSUGRA) m0 = 200 GeV m1/2 = 160 GeV A0 = −400 GeV tanβ = 10 μ > 0.410 GeV σ = 51 pb Requiring leptons costs in yield Reduces backgrounds too, though. Ann Arbor - Dec 14, 2010 ATL-PHYS-PUB-2010-010

Benchmarking in mSUGRA SUSY search prospects with 1fb-1 data Benchmarking in mSUGRA 0 and 1 lepton channels give largest significance Gluino and squark masses up to ~700 GeV should be discoverable @ 1 fb-1 (if close) ATL-PHYS-PUB-2010-010 Significant improvement can be made on Tevatron limits during the next year. CMS exclusion prospects for another mSUGRA scenario CMS NOTE 2010/008 Ann Arbor - Dec 14, 2010

Two different samplings of parameter space SUSY search prospects with 1fb-1 data Two different samplings of parameter space 14 TeV study… Can we detect the MSSM? arXiv: 1009.2539 107 points defined in pMSSM 70k found to be allowed Theoretical constraints Precision measurements (g-2)μ DM < WMAP measurement Tevatron constraints LEP constraints ATLAS has 11 different “standard” searches defined (CERN-OPEN-2008-020) Start counting… Higgs potential bounded from below EWSB WIMP LSP thermal relic density … There could be other sources of DM Ann Arbor - Dec 14, 2010

How did we do? Call 1-800-CERN… SUSY search prospects with 1fb-1 data 14 TeV study… How did we do? Call 1-800-CERN… arXiv: 1009.2539 “Discovery yield:” Systematic SM BG error 1 TeV 3 TeV 50 % 99.4 % 68.1 % 20 % 99.9 % 81.3 % Caveat… Prospino 2.1, NLO CTEQ6 All other SUSY masses 10 TeV or higher… Ann Arbor - Dec 14, 2010

A aside on long-lived particles SUSY search prospects with 1fb-1 data 14 TeV study… A aside on long-lived particles Adopted from a table in… arXiv: 1009.2539 Many models feature “CHAMPS” R-hadrons remain an option Mechanisms for LLP Ann Arbor - Dec 14, 2010

Bottom-up Several candidates in the context of SUSY SUSY search prospects with 1fb-1 data Bottom-up Several candidates in the context of SUSY : Anomalous and late ionization Cascade decays Strong production  High cross section Pair production Hadronic interactions and theoretical uncertainties make life tricky… hep-ph/0611040v2 Ann Arbor - Dec 14, 2010

MET? (jets, leptons, MET…) SUSY cascade Jet? Signatures of SMPs MU HAD SUSY search prospects with 1fb-1 data Signatures of SMPs “Anomalously ionizing muon” MET? (jets, leptons, MET…) SUSY cascade TR EM HAD MU Anomalous dE/dx or ToF Monojet searches Stopped sparticle decays  All being actively pursued by both experiments Out of time decays Jet? Ann Arbor - Dec 14, 2010

SMP prospects for the coming year SUSY search prospects with 1fb-1 data SMP prospects for the coming year 198 nb-1 284 GeV Exclusion One could hope to push coloured stable sparticle limits significantly towards 1 TeV within a year No statement on staus as yet Discovery potential: Discovery Assumptions: High squark mass for the gluino result Possible signal in muon system Ann Arbor - Dec 14, 2010

Prospects for stopped gluinos SUSY search prospects with 1fb-1 data Prospects for stopped gluinos Limiting life-time for one set of masses CMS EXO-10-003 Gluino mass limit with fixed mass splitting to the neutralino A 300 GeV gluino decaying to a 100 GeV neutralino is discoverable in weeks @ 1032 Hz/cm2 CMS NOTE 2010/008 Significance falls off steeply with mass Ann Arbor - Dec 14, 2010

Who said Nature would be “minimally” anything? SUSY search prospects with 1fb-1 data Who said Nature would be “minimally” anything? Add a baryon-number violating term to the Soft SUSY breaking part of the Lagrangian Presto: kT jets with R=0.7: Y1 is the last merging and so on… 4 jets in |η|<2.5 2 with PT > 275 GeV y2 > -0.17 y1 + 0.08 2 jets with PT > 135 GeV SPS 1a + RPV ATL-PHYS-PUB-2009-076 Lesson: Not difficult to see, but you have to look… 1 fb-1 10 TeV Ann Arbor - Dec 14, 2010

So, how’s the next year going to look? SUSY search prospects with 1fb-1 data So, how’s the next year going to look? We’re going to be looking at plots like this: Maybe you shouldn’t be expecting 70 k exclusion limits ;-) A lot will be clearer though CMS NOTE 2010/008 ATL-PHYS-PUB-2009-084 ? ? Discovery? Of what? Ann Arbor - Dec 14, 2010

Backup slides SUSY search prospects with 1fb-1 data Ann Arbor - Dec 14, 2010

CMS focus point definitions SUSY search prospects with 1fb-1 data CMS focus point definitions Ann Arbor - Dec 14, 2010