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Beate Heinemann University of Liverpool For the CDF collaboration EPS 2003, Aachen, 17.-23.7.2003 Physics Beyond the Standard Model with Photonic Final States at CDF
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2 EPS 2003, Beate Heinemann, University of Liverpool The CDF event: ee 10 -6 events expected! Exotics Searches with Photons in CDF Run II CDF at Run 2 Search for LED in Di-Photon Production Search for Anomalous Photon+Lepton Production Search for GMSB with Di-Photon+ Search for Photon + Heavy Flavour Production Search for LED with Photon+ Anomalous Couplings: W/Z+Photon CDF at Run 2 Search for LED in Di-Photon Production Search for Anomalous Photon+Lepton Production Search for GMSB with Di-Photon+ Search for Photon + Heavy Flavour Production Search for LED with Photon+ Anomalous Couplings: W/Z+Photon / ETET / ETET The CDF event: ee / ETET
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3 EPS 2003, Beate Heinemann, University of Liverpool The CDF 2 Detector The CDF 2 Detector New for Run 2 Tracking System Tracking System Silicon Vertex detector (SVX II) Silicon Vertex detector (SVX II) Intermediate silicon layers (ISL) Intermediate silicon layers (ISL) Central Outer tracker (COT) Central Outer tracker (COT) Scintillating tile forward calorimeter Scintillating tile forward calorimeter Intermediate muon detectors Intermediate muon detectors Time-Of-Flight system Time-Of-Flight system Front-end electronics (132 ns) Front-end electronics (132 ns) Trigger System (pipelined) Trigger System (pipelined) DAQ system DAQ system Retained from Run 1 Solenoidal magnet (1.4 Tesla) Solenoidal magnet (1.4 Tesla) Central Calorimeters Central Calorimeters Central Muon Detectors Central Muon Detectors
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4 EPS 2003, Beate Heinemann, University of Liverpool CDF Run 2 Luminosity CDF Run 2 Luminosity Integrated Luminosity pb -1 Data Recording Efficiency ~ 280 pb -1 delivered ~ 220 pb -1 recorded 90% efficiency ~ commissioning physics 07/2003 Physics Analyses use about 80 pb -1 recorded up to Jan 2003 (about twice as much good quality data on tape since) Data taking efficiency about 90% now Run 1b (1994-1996) 08/2001
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5 EPS 2003, Beate Heinemann, University of Liverpool Signals Backgrounds 00 Photon candidates: Isolated electromagnetic showers in the calorimeter, with no charged tracks pointing at the calorimeter cluster Two techniques for determination of photon signals; 1. EM Shower width (shape): using Shower Max. Detector 2. Probability of Conversion: using pre-radiator hits Statistical background subtraction Two techniques for determination of photon signals; 1. EM Shower width (shape): using Shower Max. Detector 2. Probability of Conversion: using pre-radiator hits Statistical background subtraction Identification of Photon Signals in CDF Central EM Calorimeter Shower Maximum Detector Pre-shower Detector -- -Jet Jet-jet CPR29±23%40±28 % 30±23% e.g. for diphoton candidates, S/B result using CPR method is..
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6 EPS 2003, Beate Heinemann, University of Liverpool Di-Photon Mass Spectrum Search Selection: 2 photons with E t >13 GeV, cosmic and beam-halo rejection cuts Main backgrounds : fakes from photon-jet and jet-jet: determined from data! Results: 1365(95)events for E t >13(25) GeV M =168GeV For M > 150 GeV Expected background: 3.3 Observed: 2.0 Run I Results (LED Search) observed: 287(192) CC(CP) events 95% C.L. Limits on eff. string scale: using a maximum likelihood fit method Run I Results (LED Search) observed: 287(192) CC(CP) events 95% C.L. Limits on eff. string scale: using a maximum likelihood fit method NO excess observed @ High invariant mass, good agreement b/w Run II Data and expectation NO excess observed @ High invariant mass, good agreement b/w Run II Data and expectation For M > 150 GeV Expected background: 4.5 0.6 Observed: 5 95 % C.L. M S > 899 / 815 GeV K LED = 1.0 ( = -1/+1, Hewett)
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7 EPS 2003, Beate Heinemann, University of Liverpool +Jets and +Leptons Search Search for + X; X=jet(s) To search for anomalous production of quarks and gluons, look in anomalous N jet production in data Search Selection: Diphoton+extra lepton(s) Main backgrounds : W/Z+ , fake , Z ,e( ) +jet Search Selection: Diphoton+extra lepton(s) Main backgrounds : W/Z+ , fake , Z ,e( ) +jet No event found Good agreement of Run II data with expectation.. Result consistent with SM Search for + X; X=lepton(s)
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8 EPS 2003, Beate Heinemann, University of Liverpool Search GMSB for + Search Selection: 2 central photons w/ Et>13(25) Cosmic/beam halo clean-up Main backgrounds : (see plot) QCD diphoton, jet mis-ID, W+photon (lost track) Results: 1392(97)events for Et>13(25) For Missing Et>25GeV Expected background: 2 2 Observed: 2 Gravitino is the LSP NLSP: Neutralino 1 G Experimental Signature: +E T Missing Et Spectrum Set cross section limit / ETET SUSY would show up as an excess of events with large Missing Energy Run 1: ee Et pp → X → GG + X
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9 EPS 2003, Beate Heinemann, University of Liverpool Search GMSB for + (II) Set the lower mass limit on the lightest chargino in GMSB: M c >113 GeV @ 95% C.L. Set the lower mass limit on the lightest chargino in GMSB: M c >113 GeV @ 95% C.L. Acceptance Events Expected / ETET
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10 EPS 2003, Beate Heinemann, University of Liverpool B Motivation Topological search sensitive to “new physics” Topological search sensitive to “new physics” Require photon and b-jet Require photon and b-jet Can look for , e, , jets in addition Can look for , e, , jets in addition Search originally motivated by Run 1 ee Et event Search originally motivated by Run 1 ee Et event E.g in MSSM: chargino + neutralino + i 0 2 E.g in MSSM: chargino + neutralino + i 0 2 0 2 -> 0 1, + 1 -> 0 1 tb 2b-jets, photon, lepton, missing Et 2b-jets, photon, lepton, missing Et Mass at sec. Vertex: separate b-, c- and light quarks
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11 EPS 2003, Beate Heinemann, University of Liverpool Photon + b-jet: A first look Cross Sections: b- : 40.6±19.4(stat.) ± 7.6(syst.) pb, LO: 68.6 pb c- : 486 ± 153(stat.) ± 88 (syst.) pb, LO: 368.4 pb Data agree with LO QCD predictions More excl. Searches and Limits on New Physics soon Mass @ sec. vertex Missing Et /GeVB-jet-γ-Mass/GeV
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12 EPS 2003, Beate Heinemann, University of Liverpool Search Selection: - one with E T > 47 GeV and | |<1 - Missing E T > 42 GeV - No jets with E T > 10 GeV - No tracks with p T > 5 GeV Results: No excess was found Expected background: 18.0 2.1 Observed: 17 Cosmic ray muons 3.9 1.0 Z + 4.8 0.5 W e 7.3 1.7 QCD diphotons 1.1 0.4 W ( )0.9 0.3 Main backgrounds: (84 pb -1 ) Randall- Sundrum Search for New Physics in + 95% C.L. upper limit on (accep. x eff. x cross-section) of 121 fb was set Run I limit: M S >0.58 TeV / ETET ADD Extra Dimensions qq G KK
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13 EPS 2003, Beate Heinemann, University of Liverpool New Physics in W Production? Sensitive to TGC ( ): e.g. compositeness of W/Z Sensitive to TGC ( ): e.g. compositeness of W/Z Run I: excess at high Et: lepton Et>25 GeV, Met>25 GeV, photon Et>25 GeV Run I: excess at high Et: lepton Et>25 GeV, Met>25 GeV, photon Et>25 GeV leptonData SM exp muon114.2 electron53.4 both167.6
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14 EPS 2003, Beate Heinemann, University of Liverpool DataBG BR(W l ) (pb) e4333%17.2±3.8 stat ±2.8 sys ±1.0 lum 3829%19.8±4.5 stat ±2.4 sys ±1.2 lum W Production s-channel diagram not present in SM Signature: high p T lepton(e ) , MET>25, photon Et>7 GeV, R( -l)>0.7 Results: No excess was found Data: 43(38) Signal MC+Background : 46.6 1.3 4.5 (36.5 0.7 3.0) … derived the cross section for Et( )>7, R>0.7 Results consistent with SM SM: B(W l ) = 18.7 ± 1.3 pb Results consistent with SM SM: B(W l ) = 18.7 ± 1.3 pb
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15 EPS 2003, Beate Heinemann, University of Liverpool Z Production Signature: two high p T lepton(e ) ( R( -l)>0.7) Results: No excess was found Data: 11(14) Signal MC+BGD : 10.8 0.9 0.6 (12.4 1.2 0.7) DataBG B(Z ll ) (pb) e114.6%5.5±1.7 stat ±0.6 sys ±0.3 lum 144.0%6.0±1.6 stat ±0.7 sys ±0.4 lum Results consistent with SM SM: B(Z ll ) = 5.4 ± 0.4 pb Results consistent with SM SM: B(Z ll ) = 5.4 ± 0.4 pb 3-body mass Photon Et cross-section for Et( )>7, R>0.7
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16 EPS 2003, Beate Heinemann, University of Liverpool Conclusions CDF is taking high quality data in Run 2 CDF is taking high quality data in Run 2 Run 2 statistics about twice of Run 1 Run 2 statistics about twice of Run 1 Covering broad range for photon searches: Covering broad range for photon searches: Model independent, LED, SUSY,… Model independent, LED, SUSY,… No evidence of new physics found No evidence of new physics found Nothing like run 1 event found yet Nothing like run 1 event found yet … but if mother nature gives it to us we will for sure find it!
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Backup Slides
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18 EPS 2003, Beate Heinemann, University of Liverpool Di-Photon Mass Spectrum Classic LHC higgs search channel Classic LHC higgs search channel SM higgs cross section factor 100 too low for TeVatron, but e.g. boso- philic higgs SM higgs cross section factor 100 too low for TeVatron, but e.g. boso- philic higgs Model independent search for “bump” in di-photon mass spectrum Model independent search for “bump” in di-photon mass spectrum No Signal, limits soon No Signal, limits soon RUN 2 Search Selection: 2 central photons with Et>13(25) Cosmic and beam halo clean-up Results: 1365 events for Et>13 GeV
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19 EPS 2003, Beate Heinemann, University of Liverpool Search for Excited Electrons Since cross-section depends on M e* & Λ, we obtain exclusion region using various values of M e* and Λ Search for the production of excited or exotic electrons (e*) in : resonance in e invariant mass in ee events: select two high p T electrons one photon (Et>25 GeV) 0 event observed: set mass limit on e* for contact interaction model: For M e* = Λ, the mass limit is 785 GeV M(e*)<785 GeV Λ = Compositeness Scale
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