1. 20 July 2000W.Murray1 DELPHI Status Or... Should we extend the run? LEPC July 2000

2. 20 July 2000W.Murray2 Talk Overview Data taking efficiency and Detector performance Standard model results Searches –Supersymmetry –Exotica –Higgs (& ZZ production!) Conclusions

3. 20 July 2000W.Murray3 Performance of DELPHI Efficiency good, average 93.3% 112.4pb -1 recorded on 20 th July –Includes 2.2pb -1 recorded outside declared physics Congratulations to the pit team

4. 20 July 2000W.Murray4 TPC Voltage problems HV problems: – wire slack in sector 6 of 12 Each trip requires new working point, – ~10 Trips so far –We ran OK for 1 month Sense wire voltage now reduced from 1435V to 1410V

5. 20 July 2000W.Murray5 TPC sector 6 1/12 running at reduced voltage, gain 40% Some compensation with shaper settings –DeDx distorted –Z 0 run shows efficiency OK TPC experts suffering more than the data so far Current running

6. 20 July 2000W.Murray6 VD performance No new problems in vertex detector Resolution as good as ever 10-20  m motion being tracked. –We welcome the Z0’s in September

7. 20 July 2000W.Murray7 S / distribution L =87.75pb -1 qq centre of mass energy/ECM, estimated from jet angles Agreement with PYTHIA 6125

8. 20 July 2000W.Murray8 Two Fermion Production

9. 20 July 2000W.Murray9 B tagging cross-check Z resonance data well described Semileptonic WW sample also OK Light quarks b quarks Non-WW

10. 20 July 2000W.Murray10 R b measurement Y2K Acts as a check on high-energy data Agrees with Zfitter

11. 20 July 2000W.Murray11 W mass Measurement 4 jets qq  qqe qq  Exc ellen t

12. 20 July 2000W.Murray12 WW cross-section Channel details:

13. 20 July 2000W.Murray13 Searches SUSY- aperitif Exotica - entrée Higgs - dessert

14. 20 July 2000W.Murray14 Single and acoplanar photons

15. 20 July 2000W.Murray15 Search for        and        ee: 27.7 exp, 26 obs. 26 obs.  : 23.0 exp, 28 obs. 28 obs. qq: 29.1 exp, 24 obs. 24 obs. 94.2pb -1 Model independent limits

16. 20 July 2000W.Murray16 Search for   production Topolgies studied: l qq, l l  qqqq & radiative l qq, l l  qqqq & radiative tan  >= 1

17. 20 July 2000W.Murray17 Search for   production Not allowed with tan  >=1 Charginos excluded to kinematic limit   >102.2GeV/c 2 for  M>10GeV/c 2

18. 20 July 2000W.Murray18 LSP mass limit Using  0 and   limits up to 2000, DELPHI can exclude LSP below 38.2GeV/c 2 Limit at tan  =1, and assuming GUT gauge mass relation. If Higgs 0.8 - 2.0 tan  exclusion applied, we get: 49GeV/c 2 tan  above 2.0 42GeV/c 2 tan  below 0.8 - Assumes m t =175GeV/c 2 and m 0 < 1TeV

19. 20 July 2000W.Murray19 Squark searches  M>15GeV/c 2 100%Br. L  91.4pb - 1

20. 20 July 2000W.Murray20 Search for sleptons 93.7pb -1 Assume l l inaccessible  =-200 tan  = 1.5 For  M>5GeV/c 2  =-200 tan  = 1.5 ObservedExpected

21. 20 July 2000W.Murray21 Stau status Stau results at Moriond interesting 93.7pb-1 @205: m  > 68GeV/c 2 See Alberto DeMin’s talk  =-200 tan  = 1.5

22. 20 July 2000W.Murray22 GMSB  searches Limit on GMSB  at least SUGRA level

23. 20 July 2000W.Murray23 RPV UDD  0 1 and  + 1 Direct   to qqq Indirect   to qqqqq 101. -1 101.7pb -1 M  + 1 >102GeV/c 2 M  0 1 >37.5GeV/c 2

24. 20 July 2000W.Murray24 Exotica Technicolour Excited leptons Flavour changing neutral currents Contact Interactions

25. 20 July 2000W.Murray25 e + e - to  Data corrected to Born level Limits, combined with other data:  + >342GeV  - >319GeV e * >323GeV for =1

26. 20 July 2000W.Murray26 Excited leptons Nice Candidate for  * production –  * decay to  E  =103GeV, p  =103GeV,0.175GeV

27. 20 July 2000W.Murray27 Excited leptons L =90.2pb -1 No sign of a significant excess Limits for f=f / and f=-f / e * also combined with  study

28. 20 July 2000W.Murray28 Technicolo(u)r Similar to Hqq; different mass pairing & 5C fit Small excess, nothing striking 100.7pb -1

29. 20 July 2000W.Murray29  T,  T limits Couplings depend upon N D, number of doublets Contours give exclusion for specific N D, solid for all N D For any ND Combine:

30. 20 July 2000W.Murray30 FCNC Single top search Gives limits on    z

31. 20 July 2000W.Murray31 The main goal of the 2000 run Invisible, Fermophobic Charged ZZ production Standard Model MSSM hA Higgs searches

32. 20 July 2000W.Murray32 Invisible Higgs M H >104.3GeV/c 2 107.0 expected Assuming H to invisible 100% ee qq 

33. 20 July 2000W.Murray33 Fermiophobic Higgs to  L =102pb -1 M H >112GeV/c 2 For 100% Br to  M H >97GeV/c 2 For SM Br to  100% SM Br

34. 20 July 2000W.Murray34 ZZ production ZZ to llqq Good description of data ZZ to bbqq Small excess of events

35. 20 July 2000W.Murray35 ZZ Cross-section L = 92.0-96.9pb -1 (channel dependent) 2 ECM bins: –204.9GeV (67%) –206.8GeV (33%) 1.06pb predicted

36. 20 July 2000W.Murray36 H + H - results 74pb -1 analysed

37. 20 July 2000W.Murray37 Hll search 1 candidate in , compatible with ZZ no good candidates in ee H 

38. 20 July 2000W.Murray38 Searches with  ’s Consistent with expectations

39. 20 July 2000W.Murray39 H  channel Sensitive to high-mass due to WW fusion Slight deficit of candidates –Consistent with background Final event has high mass!

40. 20 July 2000W.Murray40 H  candidate Mass 111GeV/c 2 B tagged rather strongly A reasonable candidate –possibly qq 

41. 20 July 2000W.Murray41 Hqq search Some excess seen No Golden candidate Several bronze Events peak around 107GeV/c 2

42. 20 July 2000W.Murray42 Hqq candidate Mass estimate 105.5GeV/c 2 Two b-tagged jets A reasonable candidate

43. 20 July 2000W.Murray43 HZ Mass distribution Some excess at high mass But partially compensated by 1999 data M H >109.0GeV/c 2 (109.2 expected)

44. 20 July 2000W.Murray44 hA search Small excess in bbbb channel. Correlated with ZZ, HZ, Technicolour Not very significant bbbb search

45. 20 July 2000W.Murray45 MSSM Higgs limits Since 1999: – gain of 1.2 GeV in expected limits –loss of 0.5-1 GeV in observed due to the excess in 4b's tan  between 0.8 and 2.0 is excluded in the pessimistic ‘m h - max’ scenario for m top =175 tan  range is 0.6 to 4.2 in the ‘no mixing’ scenario

46. 20 July 2000W.Murray46 Summary DELPHI performance is good and well understood Standard model physics processes normal No significant signals observed Our thanks to all the LEP team

47. 20 July 2000W.Murray47 Running Request To accumulate, as soon as possible, 10pb -1 at the highest possible energy. Presently this seems to be feasible running with the 2*2 scheme. In September evaluate the possibility to achieve a three sigma Higgs discovery and continue to run until it is excluded that it can be reached before Christmas. Depending upon the conclusion: aUse the reserve weeks to possibly run at higher energy by going to negative frequency shift (possibly compromising the detector backgrounds) and thus gaining 500MeV ECM bSupport a dedicated run at the W mass threshold in order to provide a competitive and independent measurement of the mass of the W. This run should aim to collect 200pb -1 before Christmas.