Diffraction at CDF and Universality of Diffractive Factorization Breaking Konstantin Goulianos The Rockefeller University / Low x 2010, June 2010 Kavala (Greece) PhillippiThassos

CONTENTS  Introduction  Diffraction at CDF: latest results  Dijets  W and Z  Jet-Gap-Jet  Universality of Diffractive Factorization Breaking

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 3 INTERACTIONS Diffractive: Colorless exchange carrying vacuum quantum numbers Non-diffractive: 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

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 4 Definitions  dN/d  M p p’ rap-gap  =-ln  0 p M ,t,t p p p’ ln M 2 ln s particles M 2 scaling: no price paid for increasing diffractive gap size

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 5 Diffractive pp(pp) CDF Single Diffraction dissociation (SD) Double Diffraction dissociation (DD) Double Pomeron Exchange (DPE)  Central Diffraction Single + Double Diffraction (SDD) SD SDD   Elastic scatteringTotal cross section  T =Im f el (t=0) OPTICAL THEOREM   gap nested gap use gap nesting until no diffractive gap fits in √s'  

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 6 M 2 scaling KG&JM, PRD 59 (1999)  factorization breaks down to ensure M 2 scaling - why? Regge 1  Independent of s over 6 orders of magnitude in M 2 !  d  dM 2 | t=-0.05 independent of s over 6 orders of magnitude ! data

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 7  T SD (pp & pp) 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’  T SD mb √s=22 GeV

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 8 REMARKS  MC generators for diffractive studies:  PYTHIA & PHOJET disagree with each other and with data.  Diffractive factorization breaking at HERA: Vector mesons:  vs. W, b-slopes of t-distributions, … Dijets: E T jet dependence, resolved vs. direct components,...  Renormalization (RENORM) model: describes both p ( p ) - p and  – p  MC based on RENORM model: MBR (Minimum Bias Rockefeller) used at CDF.  Luminosity measurement: requires a known x-section and MC predicted acceptance of a detector component.  suggest SD: well defined and slowly varying x-section

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 9 The CDF II Detector

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 10 Diffractive Structure Function  breakdown of QCD factorization !

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 11 Diffractive Structure Function CDF H1 momentum fraction of parton in “Pomeron” – note quotes Using preliminary PDF’s from same suppression as in soft diffraction – why?

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 12 Dijet E T distributions  similar for SD and ND over 4 orders of magnitude Kinematics

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 13 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 the t-distribution displays a diffraction minimum at |t| ~ 2.5 (GeV/c) 2 (?)  all three results  “ first observation ” ?????? x Bj - distribution CDF Run II Preliminary b - slope of t-distribution ?

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 14 Pomeron dominated  &  dependence of F D jj – Run I

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 15 Diffractive W / Z - analysis CDF Run II Preliminary

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 16 Diffractive W / Z - results CDF Run II Preliminary

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 17 CENTRAL GAPS Jet gap

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 18 DIFFRACTION PHENOMENOLOGY

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 19 Gap probability MUST be normalized to unity! Single Diffraction 2 independent variables: t color factor gap probability sub-energy x-section

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 20 Single diffraction (re)normalized  Pumplin bound obeyed at all impact parameters Grows slower than s 

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 21 Unitarity and Renormalization  Two free parameters: s 0 and g PPP  Obtain product g PPP s 0  from  SD  Renormalized Pomeron flux determines s 0  Get unique solution for g PPP Pomeron-proton x-section Pomeron flux  gap probability Set to unity – determines g PPP and s 0 KG, PLB 358 (1995) 379

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 22 Dijets in  p at HERA from RENORM 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)

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 23 Multi-gap Diffraction (KG, hep-ph/ )  y

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 24 Multi-gap Cross Sections Same suppression as for single gap! Gap probabilitySub-energy cross section (for regions with particles) 5 independent variables color factor

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 25 Rapidity Gaps in Fireworks

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 26 “Gap survival probability” S =

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 27 Hard Diffraction Phenomenology

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 28 Diffractive Tevatron p jet reorganize jet

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 29 F D JJ ( , Q 2 Tevatron

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 30 SD/ND dijet ratio vs. x CDF <  < Flat  dependence for  < 0.5 CDF Run I

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 31 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

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 32 Dijets in  p at HERA DIS 2008 talk by W. Slomiński, ZEUS  % apparent rise when E T jet 5  10 GeV  due to suppression at low E T jet !!!

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 33 Vector meson production (Pierre Marage, HERA-LHC 2008)  left - why different  vs. W slopes?  more room for particles  right - why smaller b-slope in  *p?  same reason

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 34 Unexpected, not understood QCD factorisation not OK Dijets in  p at HERA – 2007 Hadron-like  e Q2Q2 ** p jet  reorganize Direct vs. resolved  the reorganization diagram predicts:  suppression at low Z | P jets, since larger  is available for particles  same suppression for direct and resolved processes

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 35 Pomeron  '  and  t in a QCD inspired parton model approach

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 36  SD and ratio of  ' 

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 37 The total x-section √s F =22 GeV SUPERBALL MODEL

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 38 Monte Carlo Strategy for the LHC   T  from SUPERBALL model  optical theorem  Im f el ( t=0 )  dispersion relations  Re f el ( t=0 )  differential  SD  from RENORM  use nested pp final states for pp collisions at the IP ­ p sub-energy √s‘ See K. Goulianos, Phys. Lett. B 193 (1987) 151 pp “A new statistical description of hardonic and e+e− multiplicity distributions “  T optical theorem Im f el (t=0) dispersion relations Re f el (t=0) MONTE CARLO STRATEGY CONCUSION stay tuned …

K. Goulianos low-x June 2010 KavalaDiffraction at CDF and Universality of DFB 39 The first CMS event