CDF Searches Overview Tracey Pratt Liverpool University Extra

CDF Searches Overview Tracey Pratt Liverpool University Ø Extra Dimensional Models and their Signatures Ø Introduction to the Tevatron and CDF Ø Search channels, Search Strategy Ø Comparison of Background Expectation to Data Ø Preliminary Results Ø Summary and Outlook Tracey Pratt Euro. GDR, Frascati, Italy November 2004 1

Extra Dimensional Solutions the Hierarchy Problem (MEW << MPlanck? ) Curvature of the extra dimension Taking compact space to be very large G Gravity freely propagates in the many large extra dimensions (n>2) MPl 2 = Vn. MPl(4+n)(2+n) To solve hierarchy: MPl(4+n) ~ 1 Te. V hep-ph 9803315 Tracey Pratt Planck Te. V brane 1 highly curved extra dimension Gravity localised in the ED Scale of physical phenomena on the Te. V-brane is specified by the exponential warp factor: = MPle-k. Rc ~ Te. V if k. Rc ~11 -12. Euro. GDR, Frascati, Italy November 2004 hep-ph 9905221 2

CDF @ Tevatron pp Collider Highest energy collider operating in the world! CDF p p D 0 Run I (1992 -1996) √s 1. 8 Te. V, 110 pb-1 Run II (2001 -2009) √s 1. 96 Te. V Physics Analyses use ~200 -345 pb-1 collected between 02/02 and 07/04 Tracey Pratt pb-1 Total Luminosity 700 600 500 400 300 200 Delivered To Tape 100 0 Euro. GDR, Frascati, Italy November 2004 days 3

Experimental Signatures for Graviton emission Search for ET + jet(s), ET + V g, q G g, q d /d. M 10 -2 (pb/Ge. V) 10 -4 10– 6 M (Ge. V) Tracey Pratt f, V g, q & =+1 jet, V g, q Graviton exchange Search for deviations in cross sections and asymmetries of SM processes Run I G f, V Dilepton channel RS model Tevatron 700 Ge. V KK graviton K/MPl 1 0. 7 0. 5 0. 3 0. 2 0. 1 10 -8 400 600 800 1000 Mll (Ge. V) Euro. GDR, Frascati, Italy November 2004 Mll (Ge. V) 4

CDF ED Search Channels Channel Completed On their way! Run II Emission + ET jet + ET Virtual Graviton Exchange ee & & ee jet-jet ZZ Run II Search Strategy Aim to make generic signature-based searches (e. g. ee channel) Perform general searches comparing data to expectation So we can interpret data according to many new models (e. g. G: RS and ADD, Z’: SM, E 6; RPV )! Tracey Pratt Euro. GDR, Frascati, Italy November 2004 5

G Emission: +Et Search Selection 87 pb-1 Run I - One with ET > 55 Ge. V and | |<1 - ET > 45 Ge. V - No jets with ET > 15 Ge. V - No tracks with p. T > 5 Ge. V qq GKK Main backgrounds Cosmic ray muons 6. 3 2. 0 Z 0 + 3. 2 1. 0 W e (“ “ ) 0. 9 0. 1 Prompt diphotons 0. 4 0. 1 W ( ) 0. 3 0. 1 Results Expected background: 11. 0 2. 3 Observed: 11 Tracey Pratt Limits n=4 MD > 0. 55 Te. V n=6 MD > 0. 58 Te. V n=8 MD > 0. 60 Te. V Euro. GDR, Frascati, Italy November 2004 6

G Emission: jet(s)+Et qq g. GKK dominate sub-process for n>2 q g q g GKK q q q g GKK g g g q GKK g g falls as 1/MD Tracey Pratt n+2 n=4 GKK g g GKK q q gg g. GKK g n=2 GKK q q q g g q q qg g. GKK q q Tevatron s=2 Te. V MD = 1. 2 Te. V g GKK for all subprocesses Euro. GDR, Frascati, Italy November 2004 p. Tmin (Ge. V) from Pythia prediction from Giudice, Rattazi and Wells (hep-ph 9811291) 7

G Emission: jet(s)+ET Search Selection 84 pb-1 Run Ib jet ET 1 st 80 Ge. V, | | <1. 1 and ET>80 Ge. V a second jet is allowed if ET 2 nd > 30 Ge. V no isolated tracks in event (p. T 10 Ge. V) Main background Z( )+jets, W( )+jets. Results Expected: 274 16 Observed: 284 events. Predicted Data Predicted invisible Z Observed (84 pb-1) Relative uncertainty on the signal acceptance 25 % Limits 95 % C. L. upper limit on number of signal events: 62 Run I : MD (Te. V) > Run II 85 pb -1 n CDF (K=1. 0) D (K=1. 34) D (K=1. 3) 4 0. 77 0. 66 0. 73 0. 68 6 0. 71 0. 63 0. 65 0. 66 Tracey Pratt Euro. GDR, Frascati, Italy November 2004 ET (Ge. V) CDF Run I : Best limits from the Tevatron from searches for direct graviton emission 8

G Exchange: ee Search selection 2 two isolated e, ET > 25 Ge. V 2 central e (CC) or 1 central and 1 forward e (CP) Standard Model + Z/ l l- Extra Dimensions l+ l+ l- l- Apply energy dependent cuts for high mass efficiency Main Backgrounds Central Calorimeter | | < 1 Plug Calorimeter 1<| |<3 Solenoid Time-of-Flight Tracey Pratt COT Silicon Tracker Nexp=11. 1 Nobs=14 for Mee>300 Ge. V/c 2 Nexp= 4. 6 Nobs= 9 for Mee>350 Ge. V/c 2 Euro. GDR, Frascati, Italy November 2004 9

G Exchange: Search Selection 2 isolated PT>20 Ge. V | 1|<1, | 2|<1. 5* Veto cosmic rays using track-timing cuts Muon System | | < 1. 5 Nexp=5. 2 ± 0. 3 Nobs=6 for Mee>300 Ge. V/c 2 Nexp=3. 2 ± 0. 2 Nobs=1 for Mee>350 Ge. V/c 2 Solenoid Time-of-Flight COT Silicon Tracker Tracey Pratt * 2 may include tracks w/o -chamber information Euro. GDR, Frascati, Italy November 2004 10

G Exchange: Search Selection 2 isolated ET>15 Ge. V 2 central (CC) Standard Model Extra Backgrounds Dimensions • Standard Model diphoton production (dominant at very high masses) • Fakes: -jet and jet-jet, where jet fragments into a hard 0 Nexp=4. 2± 1. 0 Nobs=1 for Mee>300 Ge. V/c 2 Nexp=1. 5± 0. 5 Nobs=1 for Mee>350 Ge. V/c 2 Tracey Pratt Euro. GDR, Frascati, Italy November 2004 11

Extracting G Exchange ll, Limits 95 % C. L. upper limits on . BR(G→ ) are placed using ± 3 search windows around MG 95 % C. L. lower limits on string scale and upper limits on . BR(G→ll) and are placed using binned likelihood method ni : observed events ni i L( / )= i i e i= Nisig + Nibkg (Resonant particles) ni! i= Nisig( ) + Nibkg (LED spectrum) Likelihoods are integrated to give the final limits, taking into account the signal and background systematic uncertainties Sources of systematic uncertainties: Luminosity Acceptance (PDF, MC statistics. . . ) Energy/Momentum scale resolution Selection Efficiencies Background statistics and normalisation Tracey Pratt Euro. GDR, Frascati, Italy November 2004 N 95%= 95%Nsig 95%= N 95% AÕ 12

G Exchange: jet Search Selection 2 highest ET jets selected from inclusive jet samples • Fit the mass spectrum with a simple background parameterization and • Search for bumps comparable with the mass resolution. No significant evidence for a new particle Tracey Pratt Euro. GDR, Frascati, Italy November 2004 13

ADD ee Limits Set a limit on the effective Planck scale (Ms 4) using invariant mass spectrum (1 D fit) Parameterise the cross section in terms of = / Ms 4, where =± 1 (Hewett) s = s. SM + s. INT + 2 s. KK 987 959 CDF Run I: 780 768 Tracey Pratt Euro. GDR, Frascati, Italy November 2004 14

RS Graviton Limits Channel Luminosity MG(Ge. V/c 2) (pb-1) K/MPl=0. 01 K/MPl=0. 1 ee 200 640 200 170 610 ee+ 200 700 345 220 690 jetjet Tracey Pratt 75 pb-1 exclude 220 -840 Ge. V: k/MPl=0. 3 Euro. GDR, Frascati, Italy November 2004 15

Angular Distributions: ee 1 -D fits performed, but also study angular distributions cos * in Collins-Soper frame Good agreement with SM prediction Tracey Pratt Euro. GDR, Frascati, Italy November 2004 16

Angular Distributions: & cos * in Collins-Soper frame Tracey Pratt Euro. GDR, Frascati, Italy November 2004 17

Summary and Outlook Ø Searches for ED have been performed in many channels at CDF Ø No evidence of deviations from Standard Model expectation observed Ø Best limits obtained ADD jets+ET, ee + ~ 1 Te. V RS (345 pb-1) m 1 ~ 220 to 690 Ge. V for k/MPl 0. 01 to 0. 1 ee + (200 pb-1) m 1 ~ 200 to 700 Ge. V for k/MPl 0. 01 to 0. 1 Ø Many new results and publications on their way…. ee PP search ZZ channel Ø Tevatron Run IIa (2 fb-1) has a promising observation potential and should be in a position to discover ED, if they exist, ADD: up to about MS = 2 Te. V RS: m 1 from 0. 5 to 1 Te. V for k/MPl 0. 01 to 0. 1 Look out for CDF results! Tracey Pratt Euro. GDR, Frascati, Italy November 2004 18

ee(PP): Comparison to Expectation New for Run II: Plug ee increase acceptance! Search selection 2 two isolated e, ET > 25 Ge. V 2 forward e (PP) Main Non-Drell-Yan Background QCD dijets: jet is misidentified Larger effect in the plug region than in central limits being obtained! Tracey Pratt Nexp=2. 7 ± 0. 7 Nobs=8 for Mee>300 Ge. V/c 2 Nexp=1. 4 ± 0. 3 Nobs=3 for Mee>350 Ge. V/c 2 Euro. GDR, Frascati, Italy November 2004 19

Summary and Outlook Ø Searches for ED have been performed in many channels at CDF Ø No evidence of deviations from Standard Model expectation observed Ø Best limits obtained ADD jets+ET, ee + ~ 1 Te. V RS (345 pb-1) m 1 ~ 220 to 690 Ge. V for k/MPl 0. 01 to 0. 1 ee + (200 pb-1) m 1 ~ 200 to 700 Ge. V for k/MPl 0. 01 to 0. 1 Ø Many new results and publications on their way…. ee PP search ZZ channel Ø Tevatron Run IIa (2 fb-1) has a promising observation potential and should be in a position to discover ED, if they exist, ADD: up to about MS = 2 Te. V RS: m 1 from 0. 5 to 1 Te. V for k/MPl 0. 01 to 0. 1 Look out for CDF results! Tracey Pratt Euro. GDR, Frascati, Italy November 2004 20

Spin-0 Dilepton Limits RP sneutrino ` l+ l- 2 x. BR Tracey Pratt Euro. GDR, Frascati, Italy November 2004 21

Spin-1 Dilepton Limits Z' bosons CDF Run L(pb-1) Mass Limit @ 95 % Sequential Z`: Reference model Z' SM ee with SM-like couplings to fermions Run IA(92 -93) 20 505 Free parameter M(Z`) Run IB(94 -94) 90 640 590 IIA (winter 04) 200 750 735 Run I limits exceeded! E 6 Z' E 6 Model Z`: del Aguilia et al. , Nuc Phys B 287 (87) Unification of strong and EWK forces at GUT E 6→(SO(10)→SU(5)x. U(1) Z` = Z sin E 6 + Z cos E 6 Z , ZI E 6 = sin-1√ 3/8, sin-1√ 5/8 Tracey Pratt Euro. GDR, Frascati, Italy November 2004 22

Spin-1 Dilepton Limits Little Higgs Z' Solve fine-tuning and hierarchy by canceling divergences of Higgs mass SU(2) ZH coupling parameter cot First limits set! Littlest Higgs ZH (→ee) M(ZH)>800 Ge. V/c 2 for cot =1. 0 M(ZH)>755 Ge. V/c 2 for cot =0. 9 Tracey Pratt Arkani-Hamed, Cohen, Georgi, Phys. Lett. B 513, 232, 2001 Han, Logan, Mc. Elrath, Wang, Phys. Rev. D 67, 095004, 2003 Euro. GDR, Frascati, Italy 23 November 2004

Spin-1 Dilepton Limits Technicolor Tracey Pratt Euro. GDR, Frascati, Italy November 2004 24

Spin-dependent Acceptance Angular distribution and therefore acceptance of decay products depends on the spin of the decaying particle. spin-0 Tracey Pratt spin-1 Euro. GDR, Frascati, Italy November 2004 spin-2 25

CDF Run I search for LED Search Selection 2 with Et > 22 Ge. V, CC or CP: central (| | < 1), plug (1<| | <2. 4) CC 100 pb-1, CP 87 pb-1 Main backgrounds: fakes from -jet and jet-jet Results Observed: 287 Central events 192 Central Plug events Limits Using a maximum likelihood fit method 95 % C. L. MS > 899 / 797 Ge. V KLED = 1. 0 ( = -1/+1, Hewett) Central <1 Plug M highest = 288 Ge. V/c 2 < 2. 4 Tracey Pratt Euro. GDR, Frascati, Italy November 2004 26

CDF Run I ee search for LED 2 high Et isolated electrons (> 25 Ge. V) (CC and CP) Main Backgrounds: Drell-Yan, QCD di-jet, diboson production, Z , tt-bar production CC: 3319 CP: 3825 500 Ge. V Channel 95 % C. L. MS > 780 / 768 Ge. V KLED = 1. 0 95 % C. L. MS > 826 / 808 Ge. V KLED = 1. 3 ( = -1/+1, Hewett) Tracey Pratt ee and Euro. GDR, Frascati, Italy November 2004 95 % C. L. MS 2 (Hewett) Ge. V/c KLED = 1. 0 = = +1 1 780 768 899 815 905 826 27

constraints 2 fb-1 Tevatron 110 pb-1 Dijet and dilepton data 0. 20 Curvature of 5 th dimension K/MPl |R 5| < M 52 0. 10 Allowed 0. 07 Region < 10 Te. V 0. 05 Solve hierarchy LHC 10 fb-1 Dilepton data 0. 03 0. 02 0. 01 Oblique Parameters 1000 2000 3000 4000 5000 Diphoton data m 1 (Ge. V) 2 fb-1 Tracey Pratt Davoudiasl, Hewett, Rizzo hep-ph 0006041 Sridhar hep-ph 0103055 Euro. GDR, Frascati, Italy 28 November 2004

Diphoton constraints Tevatron | |<1. 2 for both K/MPl 0. 1 0. 08 LHC Using (KLED=1. 3) for full Run II a, b s = 2 Te. V L = 2 fb-1 | |<2. 5 for both K/MPl 0. 1 s = 14 Te. V 0. 08 L = 100 fb-1 0. 06 0. 04 0. 02 1000 1100 1200 1300 1400 95 % C. L. m 0 (Ge. V) 200 220 240 260 280 95 % C. L. m 0 (Ge. V) m 1 : 700 -1150 Ge. V Tracey Pratt m 1 : 3. 5 -5. 5 Te. V Euro. GDR, Frascati, Italy November 2004 hep-ph 0103055 29