Searches for SUSY in Final States with Photons

Transcription

1 SUSY4: The nd International Conference on Supersymmetry and Unification of Fundamental Interactions" -6 July 4, Manchester, England" Searches for SUSY in Final States with Photons On Behalf of the CMS Collaboration July 4" Gail G. Hanson" University of California, Riverside"

2 OUTLINE" Search for SUSY in Two Photon + Jet Events with Razor Variables at 8 TeV CMS-PAS-SUS-4-8 " " Search for Top Suark and Higgsino Production Using Diphoton Higgs Boson Decays CMS-PAS-SUS-3-4, Phys. Rev. Lett. (4) 68 "" " FIRST PRESENTED AT SUSY3 Search for Electroweak Neutralino and Chargino Production in Channels with Higgs, Z, and W Bosons at 8 TeV CMS-PAS-SUS-4-" NEW FOR ICHEP4 NEW FOR SUSY4 G. Hanson" SUSY 4, -6 July 4, Manchester, England" "

3 SEARCHES FOR STRONG AND ELECTROWEAK SUSY PRODUCTION" Many searches for strong production of SUSY but with null results" Smaller cross section for electroweak production but different tools" In this presentation will discuss both for final states involving photons" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 3"

4 Search for SUSY in Two-Photons + Jet Events with Razor Variables CMS-PAS-SUS-4-8" NEW" P P g g Simplified Model T5gg" γ γ P P P P γ γ g g General Gauge Mediation GGM" P P γ γ g g γ γ G. Hanson" SUSY 4, -6 July 4, Manchester, England" 4"

5 ANALYSIS" Two photons: isolated, cluster shape, η <.5," "p T > 3, GeV" One or more jets with p T > 4 GeV, η <.5" Event is divided into two megajets selected as the pair with the smallest sum of suared invariant masses" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 5"

6 M R M T R R M R T M R Razor Variables" ( p j + p ) j ( p j j z + p ) z E miss T ( p j j T + p ) T E miss T i p T j + p T j ( ) GGM: pp ( ~ g ~ g)/( ~ ~ ) ( G ~ γ) ( G ~ γ)+jet(s) CMS Simulation s = 8 TeV M R [TeV] Signal region: M R > 6 GeV and R >." Control region: M R > 6 GeV and. < R <. (signal contamination < %) used to fit data for M R shape" Photons that fail the cluster shape or isolation reuirements are used as a cross check of the background method" N Events - - Razor γγ + jet GGM m~ = 5 GeV, m~ g = 8 GeV GGM m~ = 7 GeV, m~ g = 5 GeV GGM m~ = 9 GeV, m~ g = 3 GeV Background Model G. Hanson" SUSY 4, -6 July 4, Manchester, England" 6" "

7 Diphoton Razor Results" N Events 3 CMS Preliminary Razor γγ + jet: Low R Fit γγ 68% Shape Systematic Fit Prediction Low R Data (γγ) - s = 8 TeV, L = 9.7 fb Sample N Events 3 CMS Preliminary - s = 8 TeV, L = 9.7 fb Razor γγ + jet: High R γγ 68% Shape Systematic Estimation in High R High R Data (γγ) Sample z-score M R [TeV] z-score M R [TeV] M R distribution in low R control region" M R distribution in high R signal region" No evidence for a signal" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 7"

8 INTERPRETATION - LIMITS" GGM Bino-like : pp ( ~ g ~ g)/( ~ ~ ) ( G ~ γ) ( G ~ γ)+jet(s) CMS Preliminary - s = 8 TeV, L = 9.7 fb pp ~ g ~ g, ~ g +, CMS Preliminary G ~ γ - s = 8 TeV, L = 9.7 fb Razor γγ + jet Expected Exclusion Expected Exclusion ± σ exp NLO Exclusion Observed Exclusion Observed Exclusion ± σ th Razor γγ + jet Expected Exclusion Expected Exclusion ± σ exp NLO+NLL Exclusion Observed Exclusion Observed Exclusion ± σ th [GeV] g m~ m~ [GeV] Mass fixed to 375 GeV" % CL upper limit on cross section [fb] [GeV] m m~ g < m m~ g [GeV] 95% CL upper limit on cross section [fb] G. Hanson" SUSY 4, -6 July 4, Manchester, England" 8"

9 Search for Top Suark and Higgsino Production Using Diphoton Higgs Boson Decays (SUS-3-4), Phys. Rev. Lett. (4) 68 " Search for natural SUSY using GMSB" First CMS Higgs tagging to search for SUSY" P P t R t R + Strong Production" H f f b b f f H First shown at SUSY3" The Higgs boson is reconstructed via the diphoton decay. " Two b uarks are also present either from decay of the other Higgs or from the top suark decay." Events are also characterized by missing transverse energy." G. Hanson" SUSY 4, -6 July 4, Manchester, England" 9"

10 Limits for Stop Quark and Higgsino Masses" m CMS, m = m s = 8 TeV, L + 5 GeV, m = m dt Natural GMSB HG ~ Higgsino model Br( ) =, Strong and EW Production Observed 95% CLs Limits Theory uncertainty Expected 95% CLs Limits Expected ±σ experimental + - = 9.7 fb + 5 GeV m~ t R Observed 95% Cross Section Exclusion (pb) G. Hanson" SUSY 4, -6 July 4, Manchester, England" "

11 Search for Electroweak Neutralino and Chargino Production in Channels with Higgs, Z, and W Bosons CMS-PAS-SUS-4- hh and hz production through GMSB model with lightest neutralino NLSP and nearly massless gravitino LSP." " NEW FOR ICHEP4 hw production through chargino-neutralino pair creation. is massive LSP." h h h P P P P P P ± h Z W ± G. Hanson" SUSY 4, -6 July 4, Manchester, England" "

12 Channels Used " Channels used for hh: ( γγ )( bb), ( bb)( bb), ( γγ )(leptons), " "(leptons)(leptons)" Channels used for hz: ( γγ )( jets), ( γγ )(leptons), " " " ( bb)(leptons), (leptons)(leptons)" Channels used for hw: ( γγ )( jets), ( γγ )(leptons), " " "( bb)(leptons),(leptons)(leptons)" Leptonic channels will be covered in another talk" G. Hanson" SUSY 4, -6 July 4, Manchester, England" "

13 h γγ Reconstruction" Two photons: isolated, cluster shape, η <.44, p T > 4, 5 GeV" h candidate is formed from two highest p T photons in the event" Diphoton invariant mass m γγ is reuired to be within Higgs boson mass region < < 3 GeV" m γγ m γγ m γγ sidebands defined by 3 8 GeV and 33 m γγ 63 GeV are used to determine background from data" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 3"

14 h bb Reconstruction" b jets identified using combined secondary vertex algorithm (CSV): displaced secondary vertices, tracks with large impact parameters, kinematic variables. Three operating points (efficiency, misidentification probability) for jets with p T > 6 GeV:" " " loose (83%, %)" " " medium (7%,.5%)" " " tight (55%,.%)" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 4"

15 h( γγ)h( bb) Channel" Exactly two tagged b jets" Invariant mass of the two b jets between 95 and 55 GeV" No identified isolated electron or muon candidates" S Th, the scalar sum of the pt s of the two Higgs candidates, is the discriminating variable" Events / GeV CMS Preliminary L = 9.5 fb Data m γ γ s = 8 TeV Sideband fit Signal, m =3 GeV Events / GeV h Higgs S T G. Hanson" SUSY 4, -6 July 4, Manchester, England" 5" CMS Preliminary - L = 9.5 fb Data Background estimate Signal, m =3 GeV Signal, m = GeV s = 8 TeV

16 Events / GeV hz and hw γγ + jets " Similar to h( γγ )h( bb) " Z or W formed from two jets with dijet mass between 7 and GeV" E miss T is the discriminating variable rather than S Th " CMS Preliminary Data L = 9.5 fb m γ γ s = 8 TeV Sideband fit Signal (x3), m =3 GeV - Events / GeV Data Prediction CMS Preliminary L = 9.5 fb - Data Background estimate Signal, m =3 GeV Signal, m = GeV s = 8 TeV G. Hanson" SUSY 4, -6 July 4, Manchester, England" 6" miss E T

17 h( bb) h( bb) Channel" With a branching fraction of.56 h bb decays represent the most likely decay mode" All jets must satisfy p T > GeV, η <.4 Exactly 4 or exactly 5 jets, with p T > 5 GeV for two highest p T jets" E miss T significance S MET > 3" No isolated charged particles" Reject fake E miss T with Δφ cut between E miss min T vector and - - CMS Preliminary L = 9.3 fb s = 8 TeV CMS Preliminary L = 9.3 fb s = 8 TeV jets" Events / GeV Data 8 6 tt Non-tt m m = 5 GeV = 4 GeV Already public in February 4" Events / S bin 8 6 4b sample Data Background estimate Signal, m = 5 GeV Signal, m = 4 GeV S MET bin bin S S bin 3 bin 4 MET MET m bb G. Hanson" SUSY 4, -6 July 4, Manchester, England" 7" S MET

18 hh GMSB Higgsino Interpretation" σ (pb) CMS Preliminary L = 9.5 fb s = 8 TeV m = m ± = m ; m ~ G hg ~ hg ~ Observed Expected ± σ exp. = GeV ± σ exp. +3σexp. NLO+NLL ± σ theory Individual expected 3l γγ bb bbbb γγ l Higgsino mass m 4 b channel is most sensitive for higgsino mass > GeV." Observed limit deviates from expected for higgsino mass less than about 7 GeV due to excess in multi-lepton channel" G. Hanson" SUSY 4, -6 July 4, Manchester, England" 8"

19 hh and hz GMSB Interpretation" σ (pb) - CMS Preliminary L = 9.5 fb s = 8 TeV m = m = m ; m ± = GeV G ~ Individual expected 3l γγ bb bbbb γγ l h + G ~ ) Br( m - CMS Preliminary L = 9.5 fb s = 8 TeV = m ± = m ; m ~ G = GeV Combined exclusion regions, all analyses Observed Expected ± σ exp. σ exp Higgsino mass m (Leptonic channels also used)" ± Higgsino mass m - CMS Preliminary L = 9.5 fb s = 8 TeV G. Hanson" SUSY 4, -6 July 4, Manchester, England" Higgsino mass m 9" hh" σ (pb) σ (pb) - - hh, hz, ZZ" - ZZ" hg ~ hg ~ Observed Expected ± σ exp. ± σ exp. +3σexp. m NLO+NLL ± σ theory Higgsino mass m CMS Preliminary - L = 9.5 fb s = 8 TeV m = m = m ; m ± = GeV G ~ = m = m ; m ± = GeV G ~ hg ~ ZG ~ events only B( hg ~ ) =.5 B( ZG ~ ) =.5 ZG ~ ZG ~ Observed Expected ± σ exp. NLO+NLL ± σ theory Individual expected Observed Expected ± σ exp. NLO+NLL ± σ theory Individual expected ± σ exp. ± σ exp l lljj 3l bb ll γγ l

20 hw Electroweak Chargino-Neutralino Pair Production Interpretation" CMS Preliminary - s = 8 TeV L = 9.5 fb M 4 8 ± M - M = M H ± (W )(H ), combined observed 95% CLs Limits expected 95% CLs Limits expected ±σ experimental Theory uncertainty (NLO) (pb) σ 95% observed M ± = M σ (fb) CMS Preliminary - s = 8 TeV L = 9.5 fb ± (W )(H ), combined Observed 95% CLs limits Expected 95% CLs limits Expected ±σ Theoretical σ NLO Theoretical uncertainty M = GeV G. Hanson" SUSY 4, -6 July 4, Manchester, England" " M ± = M

21 Combined Chargino-Neutralino Limits" More sensitivity when lepton channels are included see presentation by Santiago Folgueras on Friday!" G. Hanson" SUSY 4, -6 July 4, Manchester, England" "

22 CONCLUSIONS" New diphoton search using razor variables, interpreted in T5gg as well as GGM" First Higgs tagging in search for stop and higgsino (shown at SUSY3)" Electroweak production with Higgs tagging with photons and b s" No SUSY yet, but we are looking forward to 3 TeV data with higher cross sections in 5!" G. Hanson" SUSY 4, -6 July 4, Manchester, England" "