CDF UK Aidan Robson PPGP: 22 April 2009 Glasgow Liverpool Oxford UCL

2/18 CDF UK, PPGP 2009 Tevatron Performance 6 fb -1 delivered 5 fb -1 good data recorded by CDF 3.6 fb -1 included in winter conference analyses 2010 running is confirmed 2011 running is being bid for With 2 more years running:   double delivered luminosity   treble amount of good data currently analysed

3/18 CDF UK, PPGP 2009 Detector CDF – 2007 silicon cooling problems fixed – Expect to deplete silicon for life of experiment – Successful trigger upgrades addressed high trigger deadtimes at high instantaneous luminosity Trigger coordination Level3 trigger software Calibration coordination Calorimeter reconstruction Track reconstruction Offline infrastructure Data-handling Grid computing L1 Trigger L2 Trigger L3 Trigger Offline Reconstruction Data Handling Simulation Silicon L00 Detector performing well UK involvement

4/18 CDF UK, PPGP 2009 UK Roles in CDF Operational Associate Head of Detector Operations Co-Head of Offline Level3 trigger software coordination Offline calibration database coordination Calorimeter reconstruction leader Tracking reconstruction leader Trigger operations coordination (2007-8) Trigger and Dataset group leader (2006-7) Offline Operations manager (2006) Roles since All current unless noted. Physics Electroweak Physics co-convener x3 Exotic Physics co-convener (2007-8) Subgroup conveners: W mass and width x3 W/Z analysis H->WW analysis (2006-8) Diboson analysis B mixing and lifetimes Collaboration International finance committee Chair, Spokespersons election committee Spokespersons’ paper reading group Statistics committee Speakers committee (2006-7) Student training 9 PhD theses submitted in last 3 years

5/18 CDF UK, PPGP 2009 CDF UK Physics landscape  (W+jets) PRD77(2008)  (W+charm) PRL100(2008)  (tt) (soft lepton tag) PRD-RC in review  (  +b)  (Z+b) PRD79(2009) m W PRL99(2007) PRD77(2008)  W PRL100(2008) m t (soft lepton tag) PRD-RC in review m t (matrix element) PRD-RC in prep. B s oscillation PRL97(2006) B lifetimes  ( exclusive  ) PRL99(2007)  ( exclusive ee) PRL98(2007)  ( exclusive Z) PRL submitted H->WW PRL102(2009) ZH->llbb PRL101(2008) Z'->ee PRL99(2007) Z'->  PRL102(2009) Z'->  PRL99(2007) excited muons PRL97(2006) trileptons PRL99(2007) rare decays PRD79(2009)011104(R) Benchmark measurements Precision measurements Flavour physics Searches Advanced tools building on earlier fundamentals  Soft lepton tagging  H1 jet algorithm  Unbiased B lifetime method from displaced vertex triggers UK topics since 2006 Total CDF PRLs/PRDs 2006: : : so far : 29

6/18 CDF UK, PPGP 2009 m W,  W Detector calibration: few 1/10000 in p T and E T Detailed description of hadronic W production, decay and interaction with detector Mass extracted from fits to m T, p T and E T from W->e and W->  Tevatron m W average now better than LEP average m W = ± 48 MeV/c 2  W = 2032 ± 73 (stat+sys) MeV/c 2 m  / GeV E/p (W ➝ e ) 200 pb –1 m T / GeV

7/18 CDF UK, PPGP 2009 mtmt (1) Matrix element method, lepton + jets channel. PDF per event using signal (tt) and bck (W+jets) MEs likelihood function maximised wrt top mass, JES correction, and signal fraction m t = ± 1.4 (stat+JES) ± 1.3 (sys) GeV/c 2 = ± 1.9 (total) GeV/c 2 (2) Partially reconstructed invariant mass in soft muon b-tagged events (soft muon plus lepton from W decay) Minimal dependence on precision jet-energy calibration or precision vertex tracking. m t =181.3 ± 12.4(stat) ± 3.5(sys) GeV/c 2 Current CDF combination: m t =172.6 ± 0.9(stat) ± 1.2(sys) GeV/c 2

8/18 CDF UK, PPGP 2009 Exclusive processes Require no (extra) tracks and empty calorimeters and bunch shower counters Observe 3 candidate pp->p  p events in 0.5pb -1 Observe 8 candidate pp->pllp events in 2fb -1 (0 pass the Z selection)  (pp  p ll p) = pb [m ll >40 GeV, |  l |<4]  (Z excl ) < 0.96 pb at 95% CL  ~ 0.3 fb; signal would be BSM [cf LPAIR = pb]  (pp  p  p) = (stat) ± 0.03 (sys) pb [E T >5 GeV, |  |<1] theor: pb (Durham)

9/18 CDF UK, PPGP 2009 Rare decays B + ->  K + B 0 ->  K* B s ->  s b s s ++ -- s b s s ++ -- Never seen in a hadron collider Never seen before predicted BR(B s ->  ) = 16.1x10 -7 BRs measured relative to normalisation modes: Penguin or box processes in the Standard Model New physics can exist in the loops (BR, kinematics) relative efficiency from MC Count rare mode candidates Count control mode candidates B +   K + Abs BR (0.60±0.15±0.04)x  observation B 0   K* Abs BR (0.82±0.31±0.10)x10 -6 B s   Rel BR 95% CL Limit < 2.61x m(  K*) / GeV/c 2 m(  ) / GeV/c 2

10/18 CDF UK, PPGP 2009 Z’ and RS searches high mass m  dominated by track curvature resolution signal templates constructed for 1/m  distribution search for excess using p- value scan of mass spectrum m Z’ (SM) > 1030 GeV/c 2 at 95% CL m Z’ / TeV/c 2 m –1  / c 2 /TeV m ee / GeV/c 2

11/18 CDF UK, PPGP 2009 Higgs searches (1) ZH->llbb Find Z->ll + >=2 jets with >=1 b-tag 2D Neural Net discriminant q q’ W,Z H (2) H->WW->l l using neural networks split into 0,1,2+ jet bins low and high s/b dilepton combinations CDF H->WW analysis only All CDF+D0 Higgs analyses  < 1.45  SM at 95%CL (m H =165GeV/c 2 ) 95% CL /  SM m H (GeV/c 2 ) NN output Code to LHC!

12/18 CDF UK, PPGP 2009 CDF UK plans The Standard Model Search for H->WW Precision measurement of m W Confirmation of anomalous  s

13/18 CDF UK, PPGP 2009 CP violation in B s ->J/    B s mixing frequency well-measured Phase of mixing amplitude also required to constrain NP Large  s unequivocal sign of new physics CDF and D0 see ~2  effects; CDF favours  s ~0.8 B factories see ~5  effects in b->s transitions We are working on particle ID to improve measurement 8 fb –1 would enable 5  observation of SM-violating  s  s ~ 0.02 (SM)

14/18 CDF UK, PPGP 2009 mWmW Current CDF m W = ± 48 MeV/c 2. Working on measurement with x12 data. published (200pb -1 ) expected (2.3fb -1 )  m W stat (  ) 54 MeV16 MeV  m W stat (e) 48 MeV14 MeV  m W scale 20 MeV6 MeV Aiming for 25 MeV/c 2 measurement contains blinded offset Measurement well underway; Requires years of work by dedicated team Inst. L < 70x10 30 s –1 cm –2  2/dof = 62/50 Inst. L > 70x10 30 s –1 cm –2  2/dof = 41/50  m Z stat = 12 MeV/c 2  2/dof = 27/29

15/18 CDF UK, PPGP 2009 Higgs Mar 07 Aug 07 Feb 08 Oct 05 Jan Aug 08 Expected limits Development of sensitivity in H->WW Feb 09

16/18 CDF UK, PPGP 2009 Higgs 22 33 ’ H->WW already most sensitive channel down to ~125 GeV/c 2. Work on optimising at low mass. Better harness characteristic VBF Higgs kinematics to improve sensitivity, and look for VBF W and Z production Probability of 2  Excess Probability of 3  Evidence With 10fb –1 have good chance of 2  evidence (or conversely 95% CL exclusion) of SM Higgs over the whole mass range – before LHC experiments have results 95% CL Limit / SM L=10 fb –1 w/ improvements L=5 fb –1 w/ improvements

17/18 CDF UK, PPGP 2009 Request We request minimal funding to complete exploitation: – common fund and M&O (~£100k) – travel funding (~£100k) 70% of CDF-UK effort dedicated to physics exploitation Most effort is from academics, plus Royal Society / STFC fellowship awards Currently only 0.5FTE committed RA rolling grant effort for CDF – Request for ½ an additional RA for Higgs search

18/18 CDF UK, PPGP 2009 Summary The Tevatron is performing extremely well UK physicists have produced a raft of world-leading physics results at CDF Our ongoing analyses will remain competitive until the LHC experiments have collected substantial good data We should make the most of our investment in CDF by completing our measurement of m W and continuing to improve our Higgs search.

19/18 CDF UK, PPGP 2009 Backup

20/18 CDF UK, PPGP 2009 CDF UK Personnel

21/18 CDF UK, PPGP 2009 A physics programme During last 18 months Heading towards Higgs  (pp  ZZ)  3  (pp  H) (m H =160) UK authors (pre-2006)

22/18 CDF UK, PPGP 2009 e+e–e+e– ZHZH Z bbbb m H >114GeV m H <154GeV Higgs mass ‘bounds’

23/18 CDF UK, PPGP 2009 EWK fits Higgs mass from individual measurements pulls

24/18 CDF UK, PPGP 2009 q q’ W,Z H ’ Br m H /GeV Br WW Production Decay   / fb m H /GeV gg  H qq  WH qq  qqH qq  ZH bb  H gg,qq  ttH

25/18 CDF UK, PPGP 2009 H0H0 W+W+ l+l+ W–W– l–l– ee, e ,  ; E T Isolation m ll > 16 Z and top suppression Dilepton sample composition Drell-Yan dominated WW dominated Higgs enhanced B ZZ tt WW HHH H signal separation H0H0 W+W+ l+l+ W–W– l–l– W+W+ W–W– q q’ q 90% 10% H  WW

26/18 CDF UK, PPGP 2009 H W–W– W+W+ l –l – l+l+ NN score 0 1 var1 var2 var n Spin structure WW vs H  WW lepton   Cut-based analysis Neural net approach Looking for single final distinguishing distribution to which to fit templates for signal and background extend sensitivity Background Higgs Analysis technique

27/18 CDF UK, PPGP 2009 NN score 0 1 var1 var2 var n Background Higgs  Use Monte Carlo simulation  Apply preselection (eg E T to remove Z/γ* )  Train on backgrounds against Higgs m H =110,120…160…200 { variations: can separate ee,e ,  one for each m H  Pass signal/all backgrounds through net  Form templates for each background, add up NN 0 1  Pass templates and data to fitter E T  E T m ll E lep1 E lep2 E T sig Probabilities from leading-order matrix elements Data HWW WW DY Wg WZ ZZ t fakes E T jet1  R leptons  leptons  E T lep or jet E T jet2 N jets Neural net method 0 1 Summed in proportion …

28/18 CDF UK, PPGP 2009 Matrix element method  Use LO matrix element (MCFM) to compute event probability H  WW  l l WW  l l ZZ  ll W+parton  l +jet W  l +  E T model lepton energy resn pxpypzpxpypz lep1 LO | M | 2 : pxpypzpxpypz lep2 E x, E y parton  lepton fake rate  conversion rate x obs : (with true values y )  Compute likelihood ratio discriminator R = P s P s +  k b i P b i i k b is relative fraction of expected background contrib. P s computed for each m H  Fit templates (separately for high S/B and low S/B dilepton types)

29/18 CDF UK, PPGP 2009 Limit setting Aidan Robson Glasgow University Isolation m ll > 16 or 25 Z and top suppression signal separation Background Higgs signal x 10 events X X = some observable H 1 =SM+Higgs (of mass m H ) H 0 =SM only  Construct test statistic Q = P(data|H 1 )/P(data|H 0 ) –2lnQ =  2 (data|H 1 ) –  2 (data|H 0 ), marginalized over nuisance params except   H  Find 95 th percentile of resulting   H distribution – this is 95% CL upper limit.  When computed with collider data this is the “observed limit”  Repeat for pseudoexperiments drawn from expected distributions to build up expected outcomes  Median of expected outcomes is “expected limit” Expected outcomes 95% CL Limit/SM Median = expected limit  H (pb) 95%  H /  SM 95% rescale PDF

30/18 CDF UK, PPGP 2009 Background Higgs signal x 10 events NN output score  H (pb) 95% PDF  H /  SM 95% 0 2 rescale Q = P(data|H 1 )/P(data|H 0 ) H 1 =SM+Higgs (of mass m H ) H 0 =SM only 95% CL Limit / SM m H / GeV median 1212 illustrative m H =160 Expected Outcomes Limit setting expected limits median

31/18 CDF UK, PPGP % CL Limit / SM m H / GeV expected limit observed limit illustrative expected limit observed limit illustrative DeficitExcess Interpretation

32/18 CDF UK, PPGP 2009 CDF   = 1.0  = 0.6  = 2.0 muon chambers = 2= 2 = 3= m tracker had cal hadronic cal EM cal had cal solenoid pre-radiatorshower max silicon EM cal = 1= 1 Drift chamber to |  |<1 Further tracking from Si Calorimeter to |  |<3 Muon system to |  |<1.5