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K. Goulianos CDF RESULTS ON DIFFRACTION AND EXCLUSIVE PRODUCTION Konstantin Goulianos 14th Workshop on Elastic and Diffractive Scattering (EDS Blois Workshop ) Frontiers of QCD: From Puzzles to Discoveries December 15-21, 2011, Qui Nhon, Vietnam 1
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 2 CONTENTS INTRODUCTION DIFFRACTION Diffractive W and Z production – published Diffractive structure function in dijet production – update Rapidity gaps between jets - update EXCLUSIVE PRODUCTION Exclusive in pp collisions at 1.96 TeV – new! CONCLUSION
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 3 Diffraction at CDF in Run I Single Diffraction or Single Dissociation Double Diffraction or Double Dissociation Double Pom. Exchange or Central Dissociation Single + Double Diffraction (SDD) SD DD DPE /CD SDD Elastic scatteringTotal cross section T =Im f el (t=0) OPTICAL THEOREM gap multi-gap w / two gaps part of SD Find PRL/PRD references in http://physics.rockefeller.edu/publications.html
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 4 Definitions dN/d M p p’ gap =-ln 0 p M ,t,t p p p’ ln M 2 ln s particles =-ln No radiation no price paid for increasing diffractive gap size
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 5 Highlights of Run I Results The MBR (Minimum Bias Rockefeller) Monte Carlo was used in the forward physics program - see: http://physics.rockefeller.edu/publications.html Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 6 TOTAL SD x-SECTION Factor of ~8 (~5) suppression at √s = 1800 (540) GeV suppressed relative to Regge KG, PLB 358, 379 (1995) 1800 GeV 540 GeV M ,t,t p p p’ √s=22 GeV RENORMALIZATION Regge CDF results Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 7 DD at CDF renormalized gap probabilityx-section Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 8 SDD at CDF Excellent agreement between data and MBR (MinBiasRockefeller) MC Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 9 DPE / CD at CDF Excellent agreement between data and MBR low and high masses are correctly implemented Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 10 Hard diffraction dN/d 1.45 +/- 0.25 J/ 0.62 +/- 0.25b 1.15 +/- 0.55W 0.75 +/- 0.10JJ Fraction % Fraction: SD/ND ratio @ 1800 GeV All fractions ~ 1% (differences due to kinematics) ~ FACTORIZATION ! FACTORIZATION ! hard Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 11 Diffrr. Structure Function - DSF momentum fraction of parton in “Pomeron” suppression factor is 2.5 times larger than in soft diffraction one of the main reasons for repeating measurement in Run II with an improved forward detector system breakdown of QCD factorization PRL 84, 5043 (2000) ~ 20 Run I p+p p+[JJ+X] __
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 12 Puzzles from run I gap fractions are suppressed relative to theory predictions, both for soft (Regge) and hard diffraction …but factorization holds among processes at the same energy, just like at HERA DSF at √s=1800 GeV suppressed by factor ~ 20 while Regge by factor ~8 contradicts RENORM prediction, but…see further down in the talk Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 13 The CDF II Detector – plan view
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 14 The MiniPlugs @ CDF 3.5<|h|<5.1
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 15 Measurements w / the MiniPlugs ADC counts in MiniPlug towers in a pbar-p event at 1960 GeV. “jet” indicates an energy cluster and may be just a hadron. 1000 counts ~ 1 GeV Multiplicity of SD and ND events ENERGY MP TOWER STRUCTURE MULTIPLICITY @ POSITION NIM A 430 (1999) NIM A 496 (2003) NIM A 518 (2004)
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K. Goulianos In LO QCD W probes the quark content of diffractive exchange. Production by gluons is suppressed by a factor of S and distinguished by an associated jet. Diffractive W/Z MWMW 16 CDF Diffraction and Exclusive ProductionEDS-2011 Vietnam
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K. Goulianos M W from inclusive W e/ +v Method: compare transverse M W data with MC M W diff = 80.9± 0.7(GeV/c 2 ) 17 EDS-2011 VietnamCDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 Vietnam 18 Data and event selection 0.6 fb-1 of integrated luminosity data W Z CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 Vietnam 19 Diffractive W/Z fractions Run I: R W =1.15±0.55 % for min < <0.1 [0.88±0.21 (stat)% within 0.03 < < 0.10 & |t|<1 ~80% 68-80% ~87% f1-int =(25.6±1.2)% CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 Vietnam 20 DSF from Dijets in Run II )(xF ) F Bj ND jj Bj SD jj )(xRate )(xRate )R(x Bj ND jj Bj SD jj Bj x Bj -distribution of SD/ND ratio has no strong Q 2 dependence slope of t-distribution is independent of Q 2 for |t| < 1 (GeV/c) 2 does the t-distribution have a diffraction minimum beyond |t|=1 GeV/c) 2 ?? stay tuned, release coming soon! CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 21 Dijet E T distributions similar for SD and ND over 4 orders of magnitude Kinematics
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 22 Q 2 dependence of DSF in dijets E T jet ~ 100 GeV ! The Pomeron evolves as the proton ! Small Q 2 dependence in region 100<Q 2 <10 000 GeV 2 where d SD /dE T & d ND /dE T vary by a factor of ~10 4 !
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 23 Diffractive structure function – Run II t - dependence No diffraction dips at |t| < 1 GeV 2 No Q2 dependence in slope from inclusive up to Q 2 ~10 4 GeV 2 Fit d /dt to a double exponential: Same slope over entire region of 0 < Q 2 < ~ 10 000 GeV 2 !
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K. GoulianosEDS-2011 Vietnam 24 T SD and dijets ~8 ZEUS and H1 vs. CDF H1 ZEUS CDF KG, PLB 358 (1995) 379 T sd ~ 8 soft ** e p p p p p dijet Magnitude: same suppression factor in soft and hard diffraction! Shape of distribution: ZEUS, H1, and Tevatron – why different slapes? CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 25 GAPS BETWEEN JETS Jet gap analysis nears completion repeat at LHC at 7 TeV with higher E T forward jets
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 26 EXCLUSIVE Dijet Excl. Higgs T HEORY CALIBRATION p p _ } JJ c Exclusive dijets PRD 77, 052004 (2008) PRL 99, 242002 (2007) PRL 242001 (2007)
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 27 Exclusive production Phys.Rev.Lett. 99,242002 (2007) 3 / o evts observed 2 candidates 1 0 0 candidate V.A.Khoze et al. Eur. Phys. J C38, 475 (2005): 2 events ~ 90 fb, in agreement with theory cannot claim discovery as bgd study was made a posteriori E T > 5 GeV | |< 1.0
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K. GoulianosEDS-2011 Vietnam 28 Exclusive Dimuon Production many physics processes in this data set: 3 GeV/c 2 <M <4 GeV/c 2 exclusive c in DPE p+p →p+ + - +p c c CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 29 Exclusive J/ and (2s) J/ production 243 21 events 3.92 d /dy| y=0 = 3.92 ± 0.62 nb Theoretical Predictions 2.8 nb [Szczurek07,], 2.8 nb [Szczurek07,], 2.7 nb [Klein&Nystrand04], 2.7 nb [Klein&Nystrand04], 3.0 nb [Conclaves&Machado05], and 3.0 nb [Conclaves&Machado05], and 3.4 nb [Motkya&Watt08]. 3.4 nb [Motkya&Watt08]. s production 34 7 events 0.54 d /dy| y=0 = 0.54 ± 0.15 nb R = (2s)/J/ = 0.14 ± 0.05 In agreement with HERA: R = 0.166 ± 0.012 in a similar kinematic region Fit : 2 Gaussians + QED continuum J/ (2s) QED continuum PRL 242001 (2009)
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K. GoulianosEDS-2011 Vietnam 30 Exclusive c →J/ (→ + - )+ Allowing EM towers (E T >80MeV) large increase in the J/ peak & minor change in the (2s ) peak Evidence for: c →J/ + production J/ 286 352 = +66 events (2s) 39 40 = +1 event d /dy| y=0 = 75 ± 14 nb, compatible with theoretical predictions 160 nb (Yuan 01) 90 nb (KMR01) Allow extra EM tower PRL 242001 (2009) CDF Diffraction and Exclusive Production
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 31 Exclusive production new! (submitted to PRL: arXiv:1112.0858)
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 32 Exclusive and e + e - events
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 33 Exclusive data vs. MC
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 34 Exclusive cross section
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 35 Exclusive event candidate
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K. Goulianos Tevatron Low-s Energy Scan September 8-16 2011 √s=300 & 900 GeV (CDF already studied √s=630, 1800 &1960 GeV) MinBias events (charged particle multiplicities, dN/d , etc… Underlying event for various processes Gap-X-Gap events Tune MC generators Plan to have (some) results in summer conferences CDF data EDS-2011 VietnamCDF Diffraction and Exclusive Production 36
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 37 SUMMARY Diffractive W and Z fractions: final results based on Run II CDF data using a Roman Pot Spectrometer (RPS) to measure the recoil pbar momentum The W fraction is in good agreement with the fraction measured in Run I based on a rapidity gap analysis The Z fraction is about 10% smaller than the W fraction, just as in non- diffractive events Diffractive structure function in dijet production: no strong Q2 and/or t dependence over a wide range is there a diffraction dip in the t-distribution? coming soon Central rapidity gaps in min-bias and very forward dijet events: same dependence on = max - min Exclusive production observed/measured for several processes thank you for your attendance
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 38 BACKUP
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 39 DIFFRACTIVE AND NON-DIFFRACTIVE INTERACTIONS Diffractive gaps Colorless exchange with vacuum quantum numbers Non-diffractive no “large” gaps Color-exchange POMERONPOMERON Goal: understand the QCD nature of the diffractive exchange rapidity gap Incident hadrons acquire color and break apart CONFINEMENT Incident hadrons retain their quantum numbers remaining colorless pseudo- DECONFINEMENT p ppp p
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 40 Gap survival probability S =
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 41 Dynamic Alignment of RPS Detectors Method: iteratively adjust the RPS X and Y offsets from the nominal beam axis until a maximum in the b-slope is obtained @ t=0. Limiting factors 1-statistics 2-beam size 3-beam jitter @ CDF W /lowlum data
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 42 Pomeron dominated & dependence of F D jj – Run I
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 43 Diffractive dijets @ Tevatron p jet reorganize jet
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K. GoulianosEDS-2011 VietnamCDF Diffraction and Exclusive Production 44 Diffractive DIS @ HERA e Q2Q2 ** p jet reorganize J. Collins: factorization holds (but under what conditions?) e ** t p IP Pomeron exchangeColor reorganization Results favor color reorganization
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