Diffraction from CDF2LHC

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Diffraction from CDF2LHC
K. Goulianos Tev4LHC 3-5 February
2005 Brookhaven National Laboratory
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What is Dark Energy?

H He
M
E
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Rapidity Gaps
Bj, PRD 47 (1993) 101 regions of
(pdeudo)rapidity devoid of particles
Non-diffractive interactions
Rapidity gaps are formed by multiplicity
fluctuations.
From Poisson statistics

(rparticle density in rapidity space)
Gaps are exponentially suppressed
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CDF Run I results
http//physics.rockefeller.edu/dino/my.html
93(2004)141601
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Single Diffraction
deep sea
valence quarks
Derive diffractive from inclusive PDFs and color
factors
xx
proton
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Inclusive Single Diffraction

• Unitarity problem
• Using factorization
• and std pomeron flux
• sSD exceeds sT at
• Renormalization
• normalize the Pomeron
• flux to unity

KG, PLB 358 (1995) 379
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A Scaling Law in Diffraction
KGJM, PRD 59 (1999) 114017
Factorization breaks down in favor of M2-scaling
renormalization
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Elastic and Total Cross Sections
Total cross section power law rise with energy
1/as
Elastic cross section forward scattering
amplitude
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Soft Diffraction
(KG, hep-ph/0205141)
t
2 independent variables
gap probability
sub-energy x-section
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The Factors k and e
Experimentally
KGJM, PRD 59 (114017) 1999
CTEQ5L
fggluon fraction fqquark fraction
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Multigap Diffraction
(KG, hep-ph/0205141)
Same suppression as for single gap!
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Central and Two-Gap CDF Results

• One-gap cross sections are suppressed

• Two-gap/one-gap ratios are

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Gap Survival Probability
Results similar to predictions by Gotsman-Levin-M
aor Kaidalov-Khoze-Martin-Ryskin Soft color
interactions
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Diffractive DIS _at_ HERA
Factorization holds J. Collins
Pomeron exchange
Color reorganization
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Inclusive vs Diffractive DIS
KG, Diffraction a New Approach,
J.Phys.G26716-720,2000 e-Print Archive
hep-ph/0001092
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sdiff/sincl DIS at HERA
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Diffractive Dijets _at_ Tevatron
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FDJJ(x,b,Q2) _at_ Tevatron
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SD/ND Dijet Ratio vs xBj_at_ CDF
0.035 lt x lt 0.095
Flat x dependence
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Tevatron vs HERAFactorization Breakdown
Predicted in KG, PLB 358 (1995) 379
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New FDJJ(b) from ZEUS-LPS Data
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Restoring Factorization _at_ Tevatron
DSF from two/one gap factorization restored!
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CDF2LHC

• TOPIC STATUS
• (Q2, t) dependence of DSF close to ready
• Exclusive cc production close to ready
• Low mass states in DPE need good trigger
• Exclusive b-bbar production in DPE need
  b-trigger
• x -dependence of DSF need low lum run
• Jet-gap-Jet w/jets in miniplugs need low lum run

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Diffraction _at_ LHC

• Multigap diffraction
• Exclusive production
• of high mass states

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Summary
Derive diffractive from ND pdfs and color
factors
_at_CDF
_at_ LHC
Multigap and High Mass Exclusive Diffraction
CDF2LHC
Special low-lum run needed for low-x and JGJ