Konstantin Goulianos The Rockefeller University Diffraction at CDF and at the LHC LOW X MEETING: HOTEL VILLA SORRISO, ISCHIA ISLAND, ITALY, September

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 2 theme : factorization breaking in diffraction  pp and pp results   p and  *p results  renormalization: the common thread  diffraction at the LHC

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 3 pp and pp results

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 4 pp results from CDF JJ, b, J/   W p p JJ …ee…  exclusive soft and hard diffractive processes studied at CDF Single Diffraction dissociation (SD) Double Diffraction dissociation (DD) Double Pomeron Exchange (DPE) Single + Double Diffraction (SDD) see also CDF talks in this conference by M. Albrow and J. Pinfold SD SDD

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 5  T SD (pp & pp) Factor of ~8 (~5) suppression at √s = 1800 (540) GeV  suppressed relative to Regge prediction KG, PLB 358, 379 (1995) 1800 GeV 540 GeV M ,t,t p p p’  T SD mb

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 6 M 2 scaling  d  /dM 2 independent of s over 6 orders of magnitude! KG&JM, PRD 59 (1999)  factorization breaks down to ensure M 2 scaling! renormalization 1  Independent of s over 6 orders of magnitude in M 2 !

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 7 Gap survival probability - S S =

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 8  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? 

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 9 Dijets - E T distributions  similar for SD and ND over 4 orders of magnitude Kinematics

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 10 Dijets: diffractive structure function x Bj and Q 2 dependence E T jet ~ 100 GeV ! Small Q 2 dependence in region 100 < Q 2 < 10,000 GeV 2  Pomeron evolves as the proton!

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 11 Dijets - diffractive structure function t- dependence  No Q2 dependence in slope from inclusive to Q 2 ~10 4 GeV 2 Fit d  /dt to a double exponential  Same slope over entire region of ~1< Q 2 < 4,500 GeV 2

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 12 All fractions ~ 1% (differences due to kinematics)  ~ uniform suppression  ~ FACTORIZATION ! Hard diffractive fractions  dN/d  / J/  /- 0.25b /- 0.55W /- 0.10JJ Fraction ( %) Fraction: 1800 GeV FACTORIZATION ! Run I

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 13 Diffractive W/Z production - Run II W, Z p p p IP  Diffractive W production probes the quark content of the Pomeron  Production by gluons is suppressed by a factor of  S W, Z p p p IP R W (0.03 <  < 0.10, |t|<1)= [0.97 ± 0.05(stat) ± 0.11(syst)]% Run I: R W =1.15±0.55 % for  <0.1  estimate 0.97±0.47 % in 0.03 <  < 0.10 & |t|<1) R Z (0.03 < x < 0.10, |t|<1)= [0.85 ± 0.20(stat) ± 0.11(syst)]% Fractions R W and R Z are equal within uncertainties DIFFRACTIVE FRACTIONS

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 14 Multi-gap dijets - factorization restored! The diffractive structure function measured on the proton side in events with a leading antiproton is NOT suppressed relative to predictions based on DDIS R(SD/ND) R(DPE/SD) DSF from ratio of two/one gap: factorization restored!

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 15 Exclusive dijet and Higgs production H DPEMC Phys. Rev. D 77, ExHuME suppression factor ~ 50

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 16 Central gaps Jet gap inclusive dijets

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 17  p and  *p results

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 18 Vector meson production (Pierre Marage, HERA-LHC 2008)  left - why different  vs. W slopes?  right - why smaller b-slope in  *p?!

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 19 Unexpected, not understood Hadron-like  QCD factorisation not OK Dijets in  p at HERA [slide from summary of the HERA/LHC Workshop of March 14, 2007]

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 20 Dijets in  p at HERA DIS 2008 talk by W. Slomiński, ZEUS  % rise (?) from E T 5  10 GeV

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 21 Renormalization: the common thread  works for pp, pp,  p and  *p figure from  removes overlapping gaps!

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 22 SD: M 2 scaling is expected in QCD  dN/d  M p p’ rapgap  =-ln  0 p M ,t,t p p p’ ln M 2 ln s vacuum exchange particles

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 23 Multigap cross sections Same suppression as for single gap! Gap probabilitySub-energy cross section (for regions with particles) 5 independent variables color factor

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 24 Diffractive Tevatron p jet reorganize jet

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 25 F D JJ ( , Q 2 Tevatron

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 26 SD/ND dijet ratio vs. x CDF <  < Flat  dependence for  < 0.5 CDF Run I

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 27 Diffractive HERA e Q2Q2 ** p jet  reorganize J. Collins: factorization holds (but under what contitions?) e **  t p IP Pomeron exchangeColor reorganization  Contradicted by direct vs. resolved DIS

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 28 Inclusive vs. diffractive DIS KG, “Diffraction: a New Approach,” J.Phys.G26: ,2000 e-Print Archive: hep-ph/

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 29 Dijets in  p at HERA : the expectation Factor of ~3 suppression expected at W~200 GeV (just as in pp collisions) for both direct and resolved components K. Goulianos, POS (DIFF2006) 055 (p. 8)

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 30 Unexpected, not understood Hadron-like  QCD factorisation not OK Dijets in  p at HERA  see figure on right:   same suppression for direct and resolved processes   suppression at low z jets since larger  available for particles e Q2Q2 ** p jet  reorganize

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 31 Vector meson production (Pierre Marage, HERA-LHC 2008)  left - suppression of 20-50% at high W  more room for particles  right - suppression at low |t| for high Q 2  same reason

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 32 Diffraction at the LHC

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 33 FROM EDS 2009, 39 Jun 2009, CERN --Discussion panel "What can we learn/expect from the LHC experiments?“ K. Goulianos  goal …… understand the QCD basis of diffraction & discover new physics  TEV2LHC …confirm, extend, discover…  Tools ……….larger √s  larger ,  & E T TODO:  Elastic, diffractive, and total cross sections  Important to study partial cross section components  need topology (multiplicity, E T, …)  Hard diffraction  diffractive structure function  dijets vs. W  Multigap configurations  jet-gap-jet  d  /d  vs. E T jet  BFKL, Mueller-Navelet

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 34 Dark Energy P(  y) is exponentially suppressed Rapidity gaps are formed by multiplicity fluctuations: Non-diffractive interactions Rapidity gaps at t=0 grow with  y: Diffractive interactions 2  : negative particle density! Gravitational repulsion ?

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 35 SUMMARY  Diffraction results from CDF were presented under the physics theme of factorization breaking in diffraction.  Results from  p (  *p) interactions at HERA were also discussed focusing on factorization breaking aspects.  Renormalization of the rapidity gap probability was proposed as the common thread in explaining factorization breaking by eliminating double-counting from overlapping rapidity gaps.  Suggestions for diffractive studies at the LHC were offered, thank you for your attendance

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 36 BACKUP

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 37 The CDF II detectors RPS acceptance ~80% for 0.03 <  < 0.1 and |t| < 0.1

LOW X 2009, Ischia, September 8-13Diffraction at CDF and at the LHC K. Goulianos 38 Pomeron dominated  &  dependence of F D jj – Run I