1 / 37

Large Searches at CDF, Tevatron

Extra Dimension. Large Searches at CDF, Tevatron. Extra Dimensional models Tevatron and the CDF detector Run I & Run II searches Future reaches at the Tevatron Questions Conclusions and outlook. Tracey Pratt Liverpool University. March 2003. G.

plunkettl
Télécharger la présentation

Large Searches at CDF, Tevatron

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Extra Dimension Large Searchesat CDF, Tevatron • Extra Dimensional models • Tevatron and the CDF detector • Run I & Run II searches • Future reaches at the Tevatron • Questions • Conclusions and outlook Tracey Pratt Liverpool University March 2003 Durham Exotics Workshop

  2. G Extra dimensional solutions to the hierarchy problem(MEW << MPlanck?) ADD RS Taking the compact space to be very large Curvature of the extra dimension Planck TeV brane Many large extra dimensions (n=2-7) gravity freely propagates in the ED compactified 1 highly curved extra dimension gravity localised in the ED MPl2 = VnMPl(4+n)(2+n) Scale of physical phenomena on the TeV-brane is specified by the exponential warp factor: = Mple-kRc ~ TeV if kRc ~11-12. To solve hierarchy choose Torus Vn = 2Rcn MPl(4+n) ~ 1 TeV  requires Rc ~ 10(30/n–19) m for n  2, Rc < 1 mm Durham Exotics Workshop

  3. Searching for ED ADD New Parameter Fundamental mass scale MD and R are related to Newton’s constant GN-1 and the number of extra dimensions by GN-1= 8RnM2+nD probe Kaluza-Klein gravitons (GKK)by: 1)Direct GKK emission in association with a vector-boson Picture of cross-section for emission Gravitons, do not interact with the detector, and radiate into the bulk, appearing as missing energy: jet + MET + MET Cross section depends on the number of ED New Parameter MD = MPl(4+n) New Parameter Fundamental mass scale MD GN-1= 8RnM2+nD , where GN-1 Newton’s constant 2)Graviton exchange: virtual contribution to the scattering processes Deviations in cross sections and asymmetries of SM processes e.g. qq-bar  l+l-,   Or new processes e.g. gg  l+l-, Cross section independent of the number of ED in Hewett formalism l=+1 Run I • New Parameters (Hewett formalism) • Ms • , dimensionless parameter, 1 Mmm(GeV) Durham Exotics Workshop Gupta et. al. hep-ph/9904234 Since gravitons can propagate in the bulk, energy and momentum are not conserved in the GKK emission from the point of view of our 3+1 space-time Since the spin 2 graviton in generally a has a bulk momentum component , its spin from the point of view of our brane can appear as 0, 1 or 2 Ms is the Planck scale in the extra dimensions  is a dimensionless parameter of order  1 • Two classes of experimental tests • Graviton emission • and a photon or a jet recoiling against it, • Gravitons, do not interact with the detector, and radiate into the bulk appearing as missing energy: • jet + ET  + ET • Cross section depends on the number of extra dimensions • 2. Graviton exchange • Deviations in the cross section from SM predictions the collider signatures include single photons/Z/jets with missing ET or fermion/vector boson pair production

  4. 10-2 10-4 10–6 10-8 Dilepton channel d/dM (pb/GeV) 1 0.7 0.5 0.3 0.2 0.1 RS model Tevatron 700 GeV graviton couplings of each individual KK excitation are determined by the scale, = Mple-kRc ~ TeV.masses mn = kxne-krc (J1(xn)=0) 200 400 600 800 1000 1200 Mll (GeV) 10-2 10-4 10-6 10-8 10-10 700 GeV KK Graviton at the Tevatron k/MPl = 1,0.7,0.5,0.3,0.2,0.1 from top to bottom • New parameters: • First graviton excitation mass: m1 • A ratio: k/Mpl • = m1Mpl/kx1,, 1 = m1 x12 (k/Mpl)2 1 0.5 0.1 0.05 0.01 LHC 1500 GeV graviton Mll (GeV) Searching for ED RS 10-2 10-4 10–6 10-8 Via virtual exchange Dilepton channel d/dM (pb/GeV) K/MPl 1 0.7 0.5 0.3 0.2 0.1 KK excitations can be excited individually on resonance RS model Tevatron 700 GeV KK graviton 400 600 800 1000 Mll (GeV) 10-2 10-4 10-6 10-8 10-10 700 GeV KK Graviton at the Tevatron k/MPl = 1,0.7,0.5,0.3,0.2,0.1 from top to bottom 1 0.5 0.1 0.05 0.01 LHC The cleanest signature for graviton resonance production is an excess of events in the dilepton or dijet channel. 1500 GeV GKK and subsequent tower states K/MPl 1000 3000 5000 Mll (GeV) 6 Durham Exotics Workshop Davoudiasl, Hewett, Rizzo hep-ph0006041 (Why not diphoton ?!!) Massive eigenstates only suppressed by -1 ~ TeV-1 RS modes can be excited individually on resonance (Add BRs here?!) Via Virtual exchange but different expected cross sections/distributions from ADD model

  5. p p u u u u d d 980 GeV/c2 980 GeV/c2  s 2 TeV Tevatron pp collider Highest energy collider operating in the world! Run I (1992-1996) L ~ 110 pb-1 s  1.8 TeV Run II (2001-2006) L ~ 2000 pb-1s 2 TeV CDF D0 20 x more events Durham Exotics Workshop 8 Physics reach extended and ability to set improved limits on new physics

  6. Muon System Central Calorimeters Plug Calorimeter Solenoid COT Time-of-Flight Silicon Tracker CDF at the Tevatron Run I Run II Highlights of Upgrade Improved trigger Improved silicon tracker Improved central outer tracker New forward calorimeters Extended muon coverage Time of flight detector EM calorimeter timing (Summer 03) Taking physics quality data since February 2002 Durham Exotics Workshop CDF detector is essentially new, commissioned and now taking physics-quality data! Improved sensitivity for leptons and photons

  7. Run I Run II CDF ED Searches Emission Channels  + MET , jet+ MET Exchange Diphoton, Dielectron and combined ADD (top pair, RS Dimuon Dielectron and combined (Diphoton) (Dijet) Durham Exotics Workshop

  8. Events surviving cuts 15,046 1,475 94 11 qq  GKK 104 103 102 101 1 Events per 5 GeV 0 100 200 300 400 Corrected photon ET Run I GKK emission: Et CR cuts are timing cuts (No jets with ET > 15 GeV and No tracks with pT > 5 GeV) are to remove backgds from W and events in which mismeasurement of jet energy produces fake MEt Search Selection - One  with ET > 55 GeV and ||<1 - Missing ET > 45 GeV - No jets with ET > 15 GeV - No tracks with pT > 5 GeV 87 pb-1 The fundamental mass scale MD and R are related to Newton’s constant GN-1 and the number of extra dimensions by GN-1= 8RnM2+nD Numbers don’t add due to rounding Main backgrounds but no track is found irreducible Other backgrounds: W->e nu, where the e is misidentified as a photon W -> where the charged lepton in a leptonic W decay is lost Prompt photon-photon production where a photon is lost Dijet Photon+jet production Limits n=4 MD > 0.55 TeV n=6 MD > 0.58 TeV n=8 MD > 0.60 TeV Results Expected background: 11.0  2.3 Observed: 11 Durham Exotics Workshop CDF 5725 PRD L3 has set limit MS >1 TeV for n=2 (hep-ph0003306) Main backgrounds Cosmic rays where muon undergoes a Bremsstrahlung in the calorimeter Irreducible Z+ We (), W (),  (),jet-jet, -jet (+MEt) No signal is observed 95 % C.L. ADD limits: GN-1= 8RnM2+nD MD = 549, 581, 602 GeV n=4,6,8 extra dimensions

  9. Expected number of events with timing 22 GeV 55 GeV EM calorimeter timing Summer 2003 ! Hadronic EM Calorimeters Reducing the kinematic requirement would increase the signal by a factor of 2.8 And decrease cosmic ray background Durham Exotics Workshop

  10. q q q qqgGKK dominate sub-process for n>2 q g q g q g g q q GKK GKK GKK qggGKK q q q q q q q q q g q g g g GKK GKK GKK gggGKK g g g g g g g g g g g g GKK GKK GKK from Pythia prediction from Giudice, Rattazi and Wells (hep-ph9811291) Real GKK emission : jets+Et Tevatron s=2 TeV MD = 1.2 TeV n=2 n=4 pTmin (GeV) s falls as 1/MDn+2 for all subprocesses Durham Exotics Workshop CDF 5151 qq-bar  gG is larger for larger values of n, relative to the other sub-processes, since (gggG) and (qggG) depend on (m2/s)4 Whereas (qq-bargG) depends on (m2/s)3 This results in larger splittings at high values of MD between values of n for qg and gggG compared to qq-bargG. For n=2 qq-bar is not the dominate process, but for n>2 then this is the dominate process Dashed lines for  from Pythia Solid lines prediction from Giudice, Rattazi and Wells (hep-ph9811291)

  11. Run Ib GKK emission: jets+ET Search Selection Jet ET1st80 GeV, || <1.1 and ET>80 GeV a second jet is allowed if ET2nd > 30 GeV no isolated tracks in event (pT10 GeV) Main background Z()+jets, W()+jets. 84  4 pb-1 Results Expected: 27416 Observed: 284 events. Relative uncertainty on the signal acceptance 25 % The fundamental mass scale MD and R are related to Newton’s constant GN-1 and the number of extra dimensions by GN-1= 8RnM2+nD Limits 95 % C.L. upper limit on number of signal events:62 Best limits from the Tevatron from searches for direct graviton emission pp  jet +MEt subprocesses: qggG, qq-bargG and gggG. Main bkgd from Z+jet +jet LHC: qggG gives largest contribution Compare to LEP and Delphi results?- in the paper (for that time) Durham Exotics Workshop CDF 5151 Used Poilim (poisson statistics)  Normalise bkgd predictions to Zee+jets data and use direct normalisation of W->enu+jets as a cross check L3 gives limit Ms > 600 GeV hepph0003306 Allowing a 2nd jet: improves the signal eff. (2nd jet from ISR or FSR) And allows us to estimate the QCD bkgd using data. No tracks; reduces bkgd from W+jets

  12. Predicted results for GKK emissionjet+ET Bounds obtained by requiring Tevatron: signal>205 fb (for s=2 TeV) with the acceptance cuts |jet|<3 and EminT, jet = 150 GeV. LHC: signal>2.6 fb (for s=14 TeV) with the acceptance cuts |jet|<3 and EminT, jet = 1 TeV. PRL 82,2236 (1999) |jet|<1.1 and EminT, jet = 80 GeV G. Giudice, R. Rattazzi, J. Wells hep-ph 9811291 (1999) Durham Exotics Workshop and requiring signal significance S/B = 5, assuming bkgd cross-section known to within 10 % and requiring that the signal be more than 50 % of the background to have confidence of a discovery. LHC with 300 times more data

  13. l- q l- q l- g /Z0 KKn KKn + + q l+ q g l+ l+ + q KKn KKn + q Virtual Graviton Exchange Dilepton Channel gg initiated process Clean experimental signature. Low backgrounds Standard Model Diphoton Channel + + Extra Dimensions + Durham Exotics Workshop qq-bar and gg ->  : gg process contributes about 30 % of the cross-section Interference term of gg-> between SM and KK is not in their gamgam searches in Run I, they take this a a systematic uncert, however , interference of qq-bar term is in the MC and gg interference term about 0.1* qq-bar interference term (CDF5694)

  14. KLED KLED applies to the LED terms of the cross section, to estimate the effect of non-leading orders in LED. No estimate of KLED; so results quoted for KLED=1.0 (no correction) and 1.3 (SM-like) Generate MC templates for each piece independent of the choice of  and Ms4. Fit method used Parameterise the cross section in terms of h = / Ms4 s = sSM+ h sINT + h2 sKK + sBG events 103 102 101 1 KLED=1.3 0 200 400 600 800 1000 1200 Mgg (GeV/c2) A 3 parameter (nSM, nBG,h) unbinned likelihood function is used to extract h Durham Exotics Workshop CDF 5892,5373 A different choice of  and Ms4 would affect the templates’ relative and absolute normalisations, but not their shapes. Shapes depend only on the general structure of the lagrangian and on the pdfs. and to date (March 2002) has not been theoretically estimated. (Comment on ang distrib too ) Ms is the Planck scale in the extra dimensions  is a dimensionless parameter of order  1

  15. h<1 h<1 Plug h < 2.4 h < 2.4 CDF  Run I search for LED Search Selection 2  with Et > 22 GeV, CC or CP: central (|| < 1), plug (1<|| <2.4) Main backgrounds: fakes from -jet and jet-jet Results Observed: 287 Central Central events 192 Central Plug events Limits Using a maximum likelihood fit method CC 100 pb-1, CP 87 pb-1 2 separate analyses – CP and CC – then combined to give: 95 % C.L. MS > 899 / 797 GeV KLED = 1.0 ( = -1/+1, Hewett) MC distribution for the excluded signal shown here too Central Background falls off faster than signal. In CC above 200 GeV: Expect less than 0.2 events, as opposed to 2.5 SM gg events Mgghighest = 288 GeV/c2 Durham Exotics Workshop CDF5694 CDF: M > 150 GeV 5 events are observed where 4.5 +/-0.6 were expected with luminosity 100 pb-1 , and a limit MS > 0.9 TeV for n=4 was obtained. (hepph0003306) Problems gg interference –

  16. CDF Run I ee search for LED 2 high Et isolated electrons(> 25 GeV)(CC and CP) Main Backgrounds: Drell-Yan, QCD di-jet, diboson production, Z,tt-bar production CC: 3319 CP: 3825 NSMCP = 3883  292 (DY) NBGCP = 224  71 Observed 3825 500 GeV NSMCC = 3463  223 (DY) 95 % C.L. MS > 780 / 768 GeV ( = -1/+1, Hewett) KLED = 1.0 95 % C.L. MS > 826 / 808 GeV ( = -1/+1, Hewett) KLED = 1.3 CDF 5892 Durham Exotics Workshop Highest energy event is 500 GeV 2 separate analyses – CP and CC – then combined to give: 110 7 pb-1 KLED applies to the LED terms of the cross section, and to date (March 2002) has not been theoretically estimated. Therefore quote a SM-like K-factor result and also one where no loop corrections are assumed. ee and  CDF results cdf 5753 95 % C.L. MS > 826 / 905 GeV ( = +1/-1, Hewett) KLED = 1.0 95 % C.L. MS > 853 / 939 GeV ( = +1/-1, Hewett) KLED = 1.3

  17. CDF  + ee search for LED • Diphoton channel is more sensitive to LED than dielectrons, • because the LED production cross-section is higher • The LED dielectron analysis has a 500 GeV ee event which is more consistent with LED than the SM. CDF found that a 2 dimension fit in both invariant mass and angular distribution only gave a slight improvement over the 1-dimensional fit in their statistically limited samples. Durham Exotics Workshop CDF5753 (D0 does not include the gg process, which cdf found increases the SM cross section by about 30 %) cdf 5373 Combine the likelihoods (cdf5753) (Acounting for correlated and uncorrelated uncertainties) as advocated by Cheung and Landsberg)hep-ph/9909218

  18. Tevatron n=7-2 extra dimensions HLZ formalism: sign of interference fixed, interference term is ~ F / MS4, where F reflects the number of ED F = log(MS2/2) , n=2 F = 2/(n-2), n>2 l = p F . MS4(Hewett) 2 MS4(HLZ) Run II GKK exchange reaches ADD 95 % C.L. sensitivity limits on Ms (HLZ) Using double differential cross-sections 2 fb-1 20 fb-1 Han, Lykken and Zhang Phys Rev D 59, 105006 (1999) HLZ notation: hep-ex 0008065 D0 results: ADD Corresponds to R < 0.3 mm (n-2) and R < 2 fm (n=7) n=4 e+e- + +- +  D0 Collab. hep-ex 0008065 Durham Exotics Workshop Cheung hep-ph 0003306 Increased sensitivity to ADD model since can study angular distribution with more statistics ADD model Run I (110 pb-1) ee +  Ms 1.0-1.4 TeV for n=7-2 corresponds to R < 0.3 mm (n-2) and R < 2 fm (n=7) Run II (2 fb-1) Ms 1.3-2.5 TeV for n=7-2 n = number of extra dimensions 2 fb-1 Run II dilepton data (hep-ph 0006041) Compare to LEP? Add Z’ table numbers 95 % C.L. sensitivity limits on Ms (n=4), from , ee,  channels Using double differential cross-sections

  19. Run I Run II CDF ED Searches Emission Channels  + MET , jet+ MET Exchange Diphoton, Dielectron and combined ADD (top pair, RS Dimuon Dielectron and combined (Diphoton) (Dijet) Durham Exotics Workshop

  20. 102 101 1 10-1 10-2 Events / 5 GeV 100 200 300 400 Dimuon mass (GeV/c2) 0.1 K/MPl 0.09 0.08 0.07 95 % C.L.Excluded Region L = 16 pb-1 220 230 240 250 Initial Run II limits: ee, mm RS 16 pb-1 No deviations from the SM observed Limits set on one Z’ and RS model 16 pb-1 initial results MZ‘ > 275 GeV/c2 Now updated CDF6080,6073 Durham Exotics Workshop ICHEP 2002 Graviton mass (GeV/c2) Run 2 

  21. 55 42 25 0 limits mm 72 pb-1 RS Search selection 2 isolated m PT>20 GeV/c, ||<1 Cosmic ray rejection cuts Results Observed 775events Signal region above 150 GeV/c2 observed 4 events Limits 95 % C.L. upper limit on number of signal events:5.6 208 GeV/c2 K=1.3 CDF6344 Durham Exotics Workshop

  22. Tupper Tlower Time resolution  100 ps r z Interactionmuons Cosmic ray muons Run II cosmic ray rejectionusing the Time-of-Flight detector Tupper – Tlower ~ 2L/c for cosmic ray dimuons ~ 0 for interaction dimuons Remove cosmic rays with a cut requiring Tupper – Tlower > -5 ns Durham Exotics Workshop

  23. Run II ee search 72 pb-1 RS Search selection 2 isolated e (CC, CP) ET>25 GeV Results Observed: 4576 ee events Above 200 GeV/c2 observed 27, expected 16  8 Above 350 GeV/c2 observed 3, expected 1.1  0.3 371 GeV CDF6343 Durham Exotics Workshop

  24. 42,  3,e 0 Run II ee search 72 pb-1 RS 95 % C.L. Excluded region K=1.3 20 % rather than 50% Total acceptance Effic: for ee CC:84% CP:69% Mm: PP= 57%, XX 65%, PX 61% ee better limits than in mm channel, because plug gives e a larger acceptance and a higher efficiency per event Durham Exotics Workshop CDF6343

  25. Run II ee + mm search 72 pb-1 RS 95 % C.L. Excluded region K=1.3 Durham Exotics Workshop

  26. CDF model searches RS • Future: Add more of the  detector acceptance Use Run II dijet and diphoton searches to set RS limits |h|<0.6 55 |h|<1 42 25 |h|<1.5 0 Durham Exotics Workshop

  27. Run II dijet search at CDF Inclusive Jet samples 2 highest ET jets selected Fit of the mass spectrum with a simple background parameterisation and search for bumps comparable with mass resolution Highest mass event 1364 GeV/c2 ET=666 GeV (corr) 583 GeV (raw) h=0.31 (detector) =0.43 (correct z) ET=633 GeV (corr) 546 GeV (raw) h=-0.30 (detector) =-0.19 (correct z) No significant evidence for a new particle z h z vertex = - 25 cm CDF6248 Durham Exotics Workshop RS model dijet limits to be determined. MET/ET<6 and E<2.2 TeV J1 ET = 666 GeV (corr) 583 GeV (raw) J1 h = 0.31 (detector) = 0.43 (correct z) J2 ET = 633 GeV (corr) 546 GeV (raw) J2h = -0.30 (detector) = -0.19 (correct z)

  28. Run II diphoton search Search selection Isolated  with ET > 13 GeV, || < 0.9 No 3D tracks pointing to em cluster Main backgrounds fakes from -jet and jet-jet, where jet fragments into a hard p0 Results Highest mass event is: 168 GeV/c2 Above 150 GeV/c2: Observed 2 events Expected 3.3 events No excess observed at high invariant mass CDF6312 Durham Exotics Workshop Bins are 20 % of mass 71% from jets (loose cuts) + 29% from MC

  29. Tevatron 110 pb-1 Dijet and dilepton data 2 fb-1 Curvature of 5th dimension |R5| < M52 K/MPl  < 10 TeV Solve hierarchy LHC 10 fb-1 Dilepton data Oblique Parameters Diphoton data 2 fb-1 constraints RS 0.20 0.10 0.07 0.05 0.03 0.02 0.01 Allowed Region m1 : 700-1150 GeV 1000 2000 3000 4000 5000 m1 (GeV) Davoudiasl, Hewett, Rizzo hep-ph 0006041 Sridhar hep-ph 0103055 Durham Exotics Workshop

  30. What should the k-factor used for ED searches 1.0 as for no loop corrections ? or 1.3 like in the SM ? Justified? Not clear, since the NLO processes including gravitons are quite different than the SM NLO QCD processes s=sSM + KLED(h sINT+h2sKK) ? ? Outstanding Questions Reasonable to multiply the qq by 1.3, but also for interference (INT)and direct signal (KK)processes? qg-> gam gam is about 30 % of the cross section of qq-bar -> gam gam • Is ADD model graviton exchange in Pythia ? MC program by Ulrich Baur, but nointerference between the SM gg box diagrams and the tree-level gg graph This inference is relatively small compared to the direct KK terms, and has quite a complex analytic form. Has been computed by Eboli et al (hep-ph/9908358) Has been calculated by Eboli et al (hep-ph/9908358) Included as a systematic uncertainty (sSysINT) at present (sSysINT = 34 % sSysTotal for l=-1, 43 % for l=+1) CDF 5373 No interference between the gg SM and KK terms included in their Pythia input - this has been included into the systematics Durham Exotics Workshop (including K=1.3 increases sensitivity by about 30 GeV in exchange processes) Get Syst Uncert by varying the qq-bar interference cross-section by +/-100 % ,this is an over estimate. cdf5658 Interference term of gg-> between SM and KK is not in their gamgam searches in Run I, they take this a a systematic uncert, however , interference of qq-bar term is in the MC and gg interference term about 0.1* qq-bar interference term (CDF5694) K factor: ADD CDF ee+  use KLED = 1.0 and 1.3 “They place a KLED on the LED terms of the production cross-section: 1.0 for no loop corrections and a SM-like 1.3 for two independent cases.” (cdf 5753) used to correct the LO cross-section to NLO: Not clear, since the NLO processes including gravitons are quite different than the QCD processes (e.g. gg box diagram) that enhance SM photon production. KLED applies to the LED terms of the cross section, to estimate the effect of non-leading orders in LED. Should K=1.3 apply to the non-QCD process of graviton exchange?

  31. Conclusions and outlook • Searches performed in several channels at CDF • No evidence of deviations from Standard Model expectation observed • Bestlimits obtained ADD jets+ET, ee +  ~ 1 TeV RS ee +  m1 ~ 365 to 550 GeV for k/MPl 0.05 to 0.1 • Tevatron Run II has successfully started, the first CDF Run II results already determined and .. to be updated in the future… • 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 TeV RS: m1 from 0.5 to 1 TeV for k/MPl 0.01 to 0.1 Durham Exotics Workshop • The highest limits obtained are from the ** channel. • Many interesting channels to look in. • Run II results already coming in • To be updated in the future… ADD ee +  939 (853) GeV for =-1 (+1), KLED = 1.3 ADD jets+ET 995 for n=2, 768 for n=4 RS ee 205 to 535 GeV for k/MPl 0.025 to 0.1 • Tevatron Run II has a promising observation potential and should be in a position to discover ED, if they exist, ADD: up to about MS = 2 to 3 TeV (Runs IIa, 2 fb-1; IIb, 20 fb-1) RS: m1 from 0.5 to 1 TeV for k/MPl 0.01 to 0.1 (Run IIa, 2 fb-1)

  32. THE END! Durham Exotics Workshop

  33. Jets+MEt cdf5151 Durham Exotics Workshop

  34. CDF ll/gg LED search method 3 parameter unbinned likelihood function: nSM, nBGh=l/MS4 Bayesian gaussian prior on nSM events Bayesian gaussian prior on nBG events Poisson constraint on total number of events 110 pb-1+/- 7 Run I NSMCC = 3463  223 NSMCP = 3883  292 NBGCP = 224  71 The CC BG is negligible. Observed: CC: 3319, CP: 3825 Term to weight events according to its consistency with the SM, SM-LED interference, direct KK shapes, and BG shapes nLED(h) is the fitted number of events attributable to LED physics 1) Scan through h, and at each point, reminimise L w.r.t nSM and nBG. 2) Plot L 3) 95 % C.L. result is the value of h such that 95 % of area under the likelihood function lies between it and 0. Durham Exotics Workshop CDF 5892,5373 L = 1 e – ADD Equation! Page 15 cdf 5892 2SM2 ee and  CDF results cdf 5753 95 % C.L. MS > 826 / 905 GeV ( = +1/-1, Hewett) KLED = 1.0 95 % C.L. MS > 853 / 939 GeV ( = +1/-1, Hewett) KLED = 1.3

  35. Tevatron Durham Exotics Workshop

  36. Dimuon acceptance Durham Exotics Workshop

  37. Run II a, b 0.1 0.08 0.06 0.04 0.02 K/MPl s = 14 TeV L = 100fb-1 1000 1100 1200 1300 1400 m0 (GeV) |g|<1.2 for both g |g|<2.5 for both g Using (KLED=1.3) for full s Diphoton constraints RS Tevatron LHC ADD K factor for both and ref and add bin sizes And know method – xhi Squ !? 0.1 0.08 0.06 0.04 0.02 K/MPl s = 2 TeV L = 2fb-1 200 220 240 260 280 95 % C.L. 95 % C.L. m0 (GeV) m1 : 700-1150 GeV m1 : 3.5-5.5 TeV hep-ph 0103055 Durham Exotics Workshop LHC: can probe first graviton excitation up to ~ 3.5-5.5 TeV Diphoton production at Tevatron Run II sensitive to mass of first KK graviton resonance (m1) : 700-1150 GeV implies mass of first KK graviton resonance must lie above 700 GeV For K/MPl 0.01 to 0.1 95 % C.L. m0 Tevatron: 180-290 GeV

More Related