Running Period. Detector Progress Data Analysis. Background Studies Physics Results Highlights Physics Outlook and Goals

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1 Status Report -3 Running Period Detector Progress Data Analysis Background Studies Physics Results Highlights Physics Outlook and Goals Stathes Paganis Columbia University On behalf of the Collaboration PRC Meeting May 3

2 -3 Running Period: Data Collected: (L=45.8pb -1 ) and CTD at 95%HV /3 (L=1.55pb -1 ) Neutral Current Event Charged Current Event S. Paganis (CU) Report, PRC May 3

3 Microstrip-Vertex-Detector (MVD) 67 runs with 3.1Mio events recorded between 1/31/ and /18/3 with MVD on and DQM (> 676 nb -1 ) DAQ reliable and conforms to the specifications Run selection criteria were eprun more than k events CTD on (95% voltage) MVD on and DQM-checked ok Event selection: E-Pz > 1 abs(vtxz)<4 More than vertex tracks Less than 5 vertex tracks. electron energy > 1 GeV S. Paganis (CU) Report, PRC May 3 3

4 K S with MVD Data MVD MVD + CTD CTD Only M ππ (GeV) MVD had a successful commissioning period. The detector is running well Radiation dosage is monitored Alignment, Tracking and Vertexing are coming along nicely. S. Paganis (CU) Report, PRC May 3 4

5 Straw Tube Tracker (STT) Detector installed into in April 1 After installation a few H/W problems were identified which prevented effective data taking A committee reviewed repair plans; February 18, 3 final go-ahead for the STT repairs March/3 present: STT removed and repairs have been succesfully completed STT now installed back in and all channels are working as expected STT dismounted for repairs STT remounted after repairs S. Paganis (CU) Report, PRC May 3 5

6 Luminosity Monitors and Measurement has two luminosity monitors: photon calorimeter and spectrometer Detectors (calorimeter, spectrometer), FEE and digital electronics commissioned and operational. Both systems report lumi and beam profiles on-line to HERA via the lumi-monitor. Events () rate normalized to Lumi-Spectrometer data L = 45.8 pb -1 () L =.43 pb -1 () Full lumi used The measured Luminosity was used by several -3 studies by all physics groups. Very important for example in studies of background effects on physics. Neutral Current event rates from compared to rates normalized by the luminosity, are in very good agreement S. Paganis (CU) Report, PRC May Q da

7 Background at IP SUMMARY Understanding of background conditions has been very challenging. Effort of many people. Quantitative understanding of background achieved Modifications to IP area planned and reviewed: Significant improvement of synchrotron radiation background x1 Positron background improvement factor of Several measures to improve proton beam-gas background. After the modifications we expect that will be able to run at the highest luminosity Shutdown to effect these changes are on schedule S. Paganis (CU) Report, PRC May 3 7

8 Physics Highlights : 8 papers since last PRC, 5 abstracts submitted to EPS High E T and high Q physics: Extraction of a s from PhP Diffraction and low x: Inclusive diffraction with FPC First measurement of F L Hadronic Final States: KsKs final state in DIS Searches for new physics: Lepto-quarks and single top Heavy Flavour Physics: Charm fragmentation fractions Charm content of the photon in charm photoproduction S. Paganis (CU) Report, PRC May 3 8

9 High E T jet cross section in γp Inclusive jet cross section in γp has been measured with high precision, allowing for small exp. error a s determination a s is determined at different bins of E T : a s running is observed in a single measurement S. Paganis (CU) Report, PRC May 3 9

10 High E T jet cross section in γp a s determination from incl. jet cross sections in γp and comparison with other measurements. CDF (prel.) H1 H1 experimental uncertainty theoretical uncertainty Inclusive jet cross sections in γp (Phys Lett B 56 (3) 7) Inclusive jet cross sections in pp (Phys Rev Lett 8 () 41) Subjet multiplicity in DIS (Phys Lett B 558 (3) 41) Jet shapes in DIS (Contributed paper to IECHEP1) NLO QCD fit (Eur Phys J C 1 (1) 33) NLO QCD fit (Phys Rev D 67 (3) 17) Inclusive jet cross sections in DIS (Eur Phys J C 19 (1) 89) Inclusive jet cross sections in DIS (Phys Lett B 547 () 164) Dijet cross sections in DIS (Phys Lett B 57 (1) 7) World average (S. Bethke, hep-ex/111) a s measurement consistent with all recent measurements Small experimental uncertainties: competitive with LEP Theoretical uncertainty larger than the experimental error α s (M Z ) S. Paganis (CU) Report, PRC May 3 1

11 dσ diff /dm X (nb/gev) M X = 1. GeV GeV Inclusive Diffraction with FPC GeV 11 GeV GeV 3 GeV (prel.) GeV 4 GeV 6 GeV dσ dm diff X ~ ( W ) ( α diff IP () 1) α diff determined by fitting dσ/dm x W (GeV) 8 GeV 14 GeV 7 GeV Q = 55 GeV 4π α σtot( γ * p) = F ( x, Q ) ~ W Q (1 x) λ F~x W Q (1 x) / x λ = α tot IP ( ) 1 α tot determined by fitting the F x distributions λ S. Paganis (CU) Report, PRC May 3 11

12 α IP () σ tot (x <.1) Inclusive Diffraction with FPC dσ diff /dm X (4<M X <8 GeV) (prel.) tot α IP diff α IP α IP/ tot σ γ * p ~ dσ dm diff X ~ ( W ) α tot IP () 1 ( ) ( diff () 1) α IP W Data (4<Mx<8 GeV) show: ( tot )/ diff α IP 1+ α 1 IP 1.1 soft Pomeron 1.5 α IP/ =1+(α tot IP -1)/ Q (GeV ) For Q >1GeV α IP diff () lies above soft pomeron and its Q dependence is clearly visible. α IP diff () is half that expected from inclusive DIS α IP tot (). S. Paganis (CU) Report, PRC May 3 1

13 d σ dxdq DIS at low x: first measurement of FL [( 1+ (1 y) ) F ( x, Q ) y F ( x, Q )] a 4 L = π Q x Q sx F, F L functions of (x,q ) only, but cross section also depends on s=e Measure it at different energies y = F L 1. 1 Q = 5.5 GeV OR exploit events with hard ISR photons radiated from the lepton.8.6 e(k ).4 e(k) γ ISR. -. X P(p) -.4 (prel.) ISR 96/97 NLO-QCD F L NLO-QCD F S. Paganis (CU) Report, PRC May 3 13 x

14 Scalar Mesons + K (143) K (143) K s K s final state in DIS f (8) f (1) - a (????) a (????) + a (????) - K (143) K (143) f (8) f (1) f (137) ~ uu+dd f (15) ~?? f (171) ~ ss glueball candidate First observation of J CP =(even) ++ in DIS: two states are observed: a state consistent with f (155) and f (171) S. Paganis (CU) Report, PRC May 3 14

15 Searches: Leptoquark and single top limits ~ SCALAR LEPTOQUARKS WITH F= ( S 1 /, L ) e e λ EXCLUDED H1 CI L3 indir. limit Preliminary limit H1 direct limit (e + p, Prelim.) TEVATRON lim M LQ (GeV) vtuz NC Flavour changing coupling u γ/z κ tuγ /v tuz κ tuγ v tuz exclusion region (hep-ex/31) M TOP = 17 GeV M TOP = 175 GeV M TOP = 18 GeV Excluded by H1 (prel.) (Contributed paper to ICHEP) Excluded by CDF (Phys Rev Lett 8 (1998) 55) t κ tcγ = v tcz = b q/ l W + q /ν HERA-I limits competitive with LEP, LEP-II and Tevatron Run I. Excluded by L3 (Phys Lett B 549 () 9) S. Paganis (CU) Report, PRC May 3 15 κ tuγ

16 Heavy Flavours: charm fragm. fractions Fragmentation fractions first shown in DIS3 Combined e + e - H1 prelim. f f f f f ( c D ) =.49 ±.14( stat).8( syst).3 ±.1. ± ( c D ) =.557 ±.19( stat).13( syst).549 ± ± ( c Ds ) =.17 ±.9( stat).5( syst).11± ± ( c Λc ) =.76 ±.( stat).1 ( syst).76 ± ( c D* ) =.3±.9( stat) ( syst).35 ±.7. 63± Charm fragmentation fractions are universal S. Paganis (CU) Report, PRC May 3 16

17 Heavy Flavour Physics: dijet angular distributions Direct Resolved Resolved Resolved Dijet angular distributions in photoproduction of charm depend on the spin of the exchanged particle For quark exchange a symmetric distribution in cosθ* is expected For resolved processes we observe a steep rise of the cosθ* closer to the photon, a characteristic of a gluon exchange: most of the resolved γ contribution in charm production comes from charm from the photon charm in the photon S. Paganis (CU) Report, PRC May 3 17

18 Physics Outlook and Goals HERA-I results close to completion: Ready for HERA-II DIS and high E T jet cross sections: HERA-I: Finalize Incl. DIS and high ET jet production in DIS and PhP HERA-II: Polarization, electron running, increase high x PDF accuracy Diffraction: HERA-I: Finalize incl. diffraction and LPS 97- analysis, VM diffractive production (php+dis) HERA-II: High Q inclusive, hadr. final states, VM, D*, very high t VM, heavy VM (Υ), DVCS Searches for new physics (substructure, CI, LQ,...) HERA-I: Use final NC data to complete the contact interaction paper HERA-II: Use polarization, CC, and e - to extend CI searches. Heavy Flavour Physics: HERA-I: Finalize remaining charm and first beauty measurements HERA-II: The addition of the MVD upgrade opens the beauty sector to. S. Paganis (CU) Report, PRC May 3 18