DIFFRACTION RESULTS FROM CDF XIX International Workshop on Deep-Inelastic Scattering and Related Subjects (DIS 2011) April 11-15, 2011 Newport News, VA USA Konstantin Goulianos The Rockefeller University Representing the CDF Collaboration

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 2 CONTENTS  Diffraction at CDF in Run I  Diffraction at CDF in Run II – why?  Diffractive W and Z production  Diffractive structure function in dijet production  Central gaps in minimum bias and dijet events  Exclusive production  CONCLUSIONS

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 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 multigap w /two gaps  part of SD Find references in

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 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

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 5 Highlights of Run I Results Use MBR (Minimum Bias Rockefeller) MC for forward physics

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 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 MODEL Regge  CDF results

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 7 DD at CDF renormalized gap probabilityx-section

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 8 SDD at CDF  Excellent agreement between data and MBR (MinBiasRockefeller) MC

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 9 DPE / CD at CDF  Excellent agreement between data and MBR  low and high masses are correctly implemented

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 10 Gap survival probability S =

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 11 Hard diffractive fractions  dN/d  / J/  /- 0.25b /- 0.55W /- 0.10JJ Fraction % Fraction: SD/ND 1800 GeV All fractions ~ 1% (differences due to kinematics)  ~ FACTORIZATION ! FACTORIZATION ! Run I hard process

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 12 Diffractive Structure Function (DSF)   momentum fraction of parton in “Pomeron” suppression factor is 2.5 times larger than in soft diffraction  breakdown of QCD factorization PRL 84, 5043 (2000) This contradicted the RENORM prediction of suppression factor ~ 8  as in soft diffraction ~ 20 Run I

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 13 Puzzles from run I results  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

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 14 Diffraction at CDF in Run II - why?  Resolve question on soft vs. hard diffraction suppression – are they really different?  Make precise measurement of the DSF in dijets – sensitive to gluon pdf’s  Measure diffractive W/Z production – sensitive to quark pdf’s  Central gaps in soft and hard diffraction – BFKL, Mueller-Navelet, other  Observe and measure exclusive dijet production – important for diffractive Higgs searches

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 15 The CDF II Detector – plan view

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 16 The CDF

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 17 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 counts ~ 1 GeV Multiplicity of SD and ND events ENERGY MP TOWER STRUCTURE POSITION NIM A 430 (1999) NIM A 496 (2003) NIM A 518 (2004)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 18 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 t=0. Limiting factors 1-statistics 2-beam size 3-beam CDF W /lowlum data

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 19 RPS acceptance PRD 82, (2010)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 20 Diffractive W/Z production  In LO QCD W probes the quark content of diffractive exchange  Production by gluons is suppressed by a factor of  S, and can be distinguished from quark production by an associated jet PRD 82, (2010)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 21 Data and event selection 0.6 fb-1 of integrated luminosity data W Z

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 22 Using RPS information:  No background from gaps due to multiplicity fluctuations  No gap survival probability problem  The RPS provides accurate event-by-event  measurement  Determine the full kinematics of diffractive W production by obtaining   using the equation: where This allows determination of:  W mass and potentially (not enough range in present case)  x Bj distribution  Diffractive structure function Diffractive W/Z analysis

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 23 Reconstructed M W diff  Reconstructed W mass using the 352 diffractive events fitted with a Gaussian.

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 24 M W from inclusive W  e/  + Method: compare transverse M W data with MC

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 25  cal distribution data diffractive event enhanced region nondiffractive event region and overlaps

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 26 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)%

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 27 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   t - distribution The x Bj -distribution of the SD/ND ratio has no strong Q 2 dependence the slope of the t-distribution is independent of Q 2 for |t| < 1 (GeV/c) 2 does the t-distribution have a diffraction minimum at |t| ~ 2.5 (GeV/c) 2 (?)  all three results are / would be  “ first observation ” x Bj - distribution CDF Run II Preliminary b - slope of t-distribution ?

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 28 Diffractive structure function – Run II Q 2 - dependence E T jet ~ 100 GeV !  Small Q 2 dependence in region 100<Q 2 < GeV 2 where d  SD /dE T & d  ND /dE T vary by a factor of ~10 4  The Pomeron evolves as the proton !

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 29 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 < ~ GeV 2 !

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 30 Dijet E T distributions  similar for SD and ND over 4 orders of magnitude Kinematics

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 31 CENTRAL GAPS Jet gap

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 32  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? 

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 33 EXCLUSIVE Dijet  Excl. Higgs T HEORY CALIBRATION p p _ } JJ   c Exclusive dijets PRD 77, (2008) PRL 99, (2007) PRL (2007)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 34 Exclusive  production Phys.Rev.Lett. 99, (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

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 35 Exclusive Dimuon Production 35  many physics processes in this data set: 3 GeV/c 2 <M  <4 GeV/c 2 exclusive  c in DPE p+p →p+  +  - +p

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 36 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 = ± in a similar kinematic region Fit : 2 Gaussians + QED continuum J/   (2s) QED continuum PRL (2009)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 37 Exclusive  c →J/  (→  +  - )+  37  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 (2009)

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 38 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 t dependence over a wide range  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

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 39 BACKUP

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 40 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

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 41 Pomeron dominated  &  dependence of F D jj – Run I

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 42 Diffractive Tevatron p jet reorganize jet

K. Goulianos DIS 2011, Newport News, VA, USADiffraction Results from CDF 43 Diffractive 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