CDF Experiment in JFY2002 Shin-Hong Kim (University of Tsukuba) May 30, 2003 at KEK

Tevatron status Luminosity goals for Run Ⅱ a : 5-8x10 31 cm -2 sec -1 w/o Recycler 2x10 32 cm -2 sec -1 with Recycler 2 fb -1 in 2005 → Run Ⅱ b Achieved: 4.6 x10 31 cm -2 sec -1 in May ’ pb -1 delivered until April ’03 –170 pb -1 are on tape –70 pb -1 analysed for 2003 winter conference Schedule: fb -1 in total by October fb -1 in Run Ⅱ a by the end of fb -1 in Run Ⅱ a + Run Ⅱ b Initial Luminosity July 01 Now Integrated Luminosity Delivered On tape 220 pb pb

Front End Electronics Triggers / DAQ (pipeline) Online & Offline Software Silicon Microstrip Tracker Time-of-Flight Drift Chamber Plug Calor. Muon Old New Partially New Muon System Solenoid Central Calor. Japan Group Contribution ○ Plug Calorimeter Scintillating tile/fiber unit ○ Silicon Microstrip detector SVX Ⅱ Silicon sensor ○ Inetrmediate Silicon Layer ISL Silicon sensor ○ DAQ Data logger, Monitor ○ TOF Counter Fine-mesh photomultiplier ○ Run Ⅱ b Silicon detector SVX Ⅱ b ○ Run Ⅱ b Central Preshower Counter CPR2

Physics Results from Run Ⅱ a (~70pb -1 ) –W and Z boson production cross section, decay width, Wγ production cross section –Top quark production cross section and mass –Masses and lifetimes of B-hadrons –J/ψ production cross section list

W and Z production MTMT l Require two isolated energetic leptons äNegligible backgrounds l Essential for Detector Calibrations äEnergy scale and resolution äID efficiency ● Koji Ikado (Waseda) worked on the electron-ID and energy scale study. Isolated energetic lepton and high missing E T Need more study for missing E T calibration

W and Z production cross section:  SampleBack.  B(W-->l l ) (nb) e %2.64±0.01 stat ±0.09 sys ±0.16 lum  %2.64±0.02 stat ±0.12 sys ±0.16 lum  %2.62±0.07 stat ±0.21 sys ±0.16 lum Sample  B(Z-->ll) (pb) e ±6 stat ±15 sys ±16 lum  ±6 stat ±12 sys ±15 lum  B(W-->l ) and  B(Z-->ll) at E CM =2TeV are consistent with standard model prediction.  (pp  Z)  (W)  (Z  ee)  (pp  W)  (W  e )  (Z) R R = Theoreticalprediction PDGSMPDGcombinedExpMeasure Extract R =  0.18 stat  0.33 sys → Γ(W) = 2.15  0.04 stat  0.07 sys GeV consistent with S.M. prediction of 2.09 GeV consistent with S.M. prediction of 2.09 GeV Background ~ 0.5%

Wγ Production l Signature äOne high p T lepton äOne photon (  R(  -l)>0.7) äHigh missing E T l Results consistent with SM äSM:  B(W  -->l  ) = 18.7 ±1.3 pb SampleBack.  B(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 ● Naho Tanimoto (Okayama) performed the muon channel analysis.

Top quark pair production candidate event Jet1 (b-tagged) Jet3 (b-tagged) Jet2 Jet4 Muon Muon + Missing ET + 4Jets event(with 2b-tagged jets)

Top quark pair production cross section l Signature (W + 3 or more jets with b-tag) äOne high p T Isolated lepton äVeto Z, cosmic, conversion äMissing E T > 20 GeV ä3 or more jets with E T >15 GeV ä1 jet with secondary vertex tag l B tag improves S/B 1/6  3/1 l Find 15 candidate events in 57.5 pb -1 l Expect 3.8 ± 0.5 background events  tt =5.3 ±1.9 stat ±0.8 sys pb Theoretical prediction = 6.5 pb ● Koji Sato (Tsukuba) studied the acceptance and the secondary vertex tag. ● Soushi Tsuno (Tsukuba) worked on the study of the simulation and data comparison.

Top Quark Mass l Select l +4 jet events Same as cross section, but no b tags l 33 candidate events l Method ä24 combinations in an event ä2-C fit applied, lowest  2 is chosen to get mass for each event äA continuous likelihood method is used with parameterized mass templates äM top is the minimum of log- likelihood distribution l Systematic uncertainty will be improved with understanding of detector

B s Lifetime; B s  J/  φ Use control channels: B u  J/  K + and B d  J/  K 0* Measurement limited only by statistics CDF Preliminary B+B  0.07  0.02 (ps) BdBd 1.42  0.09  0.02 (ps) BsBs 1.26  0.2  0.02 (ps) CDF: largest fully reconstructed sample in the world: 74  11 events Yield/Lum. = 2 x RunI

First Steps towards B s Mixing in CDF B s Mixing Sample B s  D s (*)   [  ]   [[KK]  ]  Collect more data and understand tagging ● Satoru Uozumi (Tsukuba) is working on the B s mixing in B s  D s (*) lν channel. B s Mixing Backup Sample B s  D s (*) lν  [  ] lν  [[KK]  ] lν HIGH STATISTICS SAMPLE: good S/N, limited time resolution

J/ψ Production Cross Section  (pp  J/  ; p T >0; |  |<0.6) = 240  1 (stat)  35/28(syst) nb In Run Ⅰ, CDF observed anomalous direct production of J/ψ and ψ(2s) in P T > 5 GeV/c which was 50 times larger than QCD theoretical prediction. In Run Ⅱ, CDF measured the J/ψ production cross section in the whole P T region, which is consitent with Run Ⅰ measurement. ● Tomohiro Yamashita (Okayama) worked on the J/ψ reconstruction and acceptance study.

Expected Physics Capability in Run Ⅱ – B s – B s mixing ( if x s < 25, observed at 200pb -1 ) – Masses of top quark and W boson → – Direct search for Higgs particle →

Electroweak Precision Measurements Run IIa EW Meas : M Higgs <193 LEP II Higgs Searches : M Higgs > 113 LEP II M Higgs = 115 GeV Tevatron Run I : M top = GeV/c 2 M W = GeV/c 2 Run Ⅱ a: ΔM top < 3 GeV/c 2 ΔM W ～ 30 MeV/c 2 → ΔM Higgs ～ 30%

Higgs Search Capability at Tevatron (will be revised in this June) M H < 130 GeV/c 2 pp →WHX →l  +  bb + X 125 < M H < 160 GeV/c 2 pp →WHX →l  +W* W*+X (like-sign dilepton +jets) 150 GeV/c 2 < M H pp →HX →WW X →l  l  X (RUN2A) (RUN2B) RUN2A( ～ 2005) exclude M H < 120 GeV/c 2 at 95 ％ C.L. RUN2B(2005 ～ ) exclude M H < 190 GeV/c 2 at 95 ％ C.L 3σ evidence for M H < 130 GeV/c 2 or 155 GeV/c 2 M H < 175 GeV/c 2