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ISMD 2004

DIFFRACTION FROM THE DEEP SEA. ISMD 2004. Konstantin Goulianos The Rockefeller University. 26 July – 1 August 2004 Sonoma County, California, USA. proton. l g =0.5. l q =0.3. in the deep sea. e g =0.20. e q =0. 04. e R =-0.5. Introduction. Four Decades of Diffraction.

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ISMD 2004

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  1. DIFFRACTION FROM THE DEEP SEA ISMD 2004 Konstantin Goulianos The Rockefeller University 26 July – 1 August 2004 Sonoma County, California, USA

  2. proton lg=0.5 lq=0.3 in the deep sea eg=0.20 eq=0. 04 eR=-0.5 Introduction Diffraction from the Deep Sea

  3. Four Decades of Diffraction • 1960’s Good and Walker • BNL: first observation • 1970’s Fermilab fixed target, ISR, SPS • Regge factorization works • KG, Phys. Rep. 101, 169 (1983) • 1980’s UA8: diff. dijets a hard diffraction • 1990’s Tevatron: Regge factorization breakdown • TeV, HERA: QCD factorization breakdown Diffraction from the Deep Sea

  4. 1/M2 law in QCD: X f y POMERON: color singlet w/vacuum quantum numbers KG, Phys. Rep. 101 (1983) 171 Soft Diffraction Diffraction from the Deep Sea

  5. QCD expectations f y The exponential rise of sT(Dy’) is due to the increase of wee partons with Dy’ (see E. Levin, An Introduction to Pomerons,Preprint DESY 98-120) f y Total & Elastic Cross Sections Diffraction from the Deep Sea

  6. Renormalization • Unitarity problem: With factorization and std pomeron flux sSD exceeds sT at • Renormalization: normalize the Pomeron flux to unity KG, PLB 358 (1995) 379 Diffraction from the Deep Sea

  7. A Scaling Law in Diffraction KG&JM, PRD 59 (1999) 114017 Factorization breaks down in favor of M2-scaling renormalization 1 Diffraction from the Deep Sea

  8. color factor Partonic Basis of Renormalization (KG, hep-ph/0205141) t 2 independent variables: Gap probability Renormalization removes the s-dependence SCALING Diffraction from the Deep Sea

  9. Color factor: Pomeron intercept: lg=0.20 lq=0.04 lR=-0.5 The Factors k and e Experimentally: KG&JM, PRD 59 (114017) 1999 CTEQ5L fg=gluon fraction fq=quark fraction Diffraction from the Deep Sea

  10. Central and Double Gaps • Double Diffraction Dissociation • One central gap • Double Pomeron Exchange • Two forward gaps • SDD: Single+Double Diffraction • One forward + one central gap Diffraction from the Deep Sea

  11. 5 independent variables color factors Gap probability Sub-energy cross section (for regions with particles) Generalized Renormalization (KG, hep-ph/0205141) Same suppression as for single gap! Diffraction from the Deep Sea

  12. Differential shapes agree with Regge predictions DD SDD DPE • One-gap cross sections are suppressed • Two-gap/one-gap ratios are Central & Double-Gap Results Diffraction from the Deep Sea

  13. S = Soft Gap Survival Probability Diffraction from the Deep Sea

  14. Soft Diffraction Conclusions Experiment: • M2– scaling • Non-suppressed double-gap to single-gap ratios Phenomenology: • Generalized renormalization • Obtain Pomeron intercept and tripe-Pomeron coupling from inclusive PDF’s and color factors Diffraction from the Deep Sea

  15. SOFT DIFFRACTION HARD DIFFRACTION MX dN/dh dN/dh Dh=-lnx h ln MX2 t x=DPL/PL x=fractional momentum loss of scattered (anti)proton Additional variables: (x, Q2) Variables: (x, t) or (Dh, t) Soft vs Hard Diffraction Diffraction from the Deep Sea

  16. Run-IC Run-IA,B Forward Detectors BBC 3.2<h<5.9 FCAL 2.4<h<4.2 CDF-I Diffraction from the Deep Sea

  17. X Fraction(%) W 1.15 (0.55) JJ 0.75 (0.10) b 0.62 (0.25) J/y 1.45 (0.25) Diffractive Fractions @ CDF SD/ND fraction at 1800 GeV DD/ND gap fraction at 1800 GeV • All SD/ND fractions ~1% • Gluon fraction • Suppression by ~5 relative to HERA •  gap survival probability ~20% Factorization OK @ Tevatron at 1800 GeV (single energy) ? Diffraction from the Deep Sea

  18. Difftactive Structure F‘n @CDF • Measure ratio of SD/ND dijet rates as a f’n of • In LO-QCD ratio of rates equals ratio of structure fn’s SD/ND Rates vs Diffraction from the Deep Sea

  19. IP IP p p p p Breakdown of QCD Factorization The clue to understanding the Pomeron HERA TEVATRON p x,t IP g* H1 e CDF gap gap dN/dh dN/dh h h ??? Diffraction from the Deep Sea

  20. R(SD/ND) R(DPE/SD) DSF from double-gaps: Factorization restored! DSF from single-gaps Restoring Diffractive Factorization Diffraction from the Deep Sea

  21. ~ no Q2 dependence ~ flat at HERA ~ 1/x0.5 at Tevatron Q2 dependence of DSF Pomeron evolves similarly to proton except for for renormalizartion effects Diffraction from the Deep Sea

  22. lg=0.5 lq=0.3 Diffractive Structure Functionfrom the Deep Sea eg=0.20 Power-law region xmax = 0.1 xmax = 0.1 b < 0.05x eq=0. 04 eR=-0.5 Diffraction from the Deep Sea

  23. RENORM Pomeron Intercept from H1 1+l Diffraction from the Deep Sea

  24. lg=0.5 lq=0.3 Pomeron dominated x-dependence: Inclusive vs Dijets Diffraction from the Deep Sea

  25. Question Gap Between Jets Diffraction from the Deep Sea

  26. Summary SOFT DIFFRACTION • M2– scaling • Non-suppressed double-gap to single-gap ratios • Flavor-independent SD/ND ratio • Little or no Q2-dependence in SD/ND ratio HARD DIFFRACTION • Universality of gap probability in soft and hard diffraction • Pomeron evolves similarly to proton Diffraction appears to be a low-x partonic exchange subject to color constraints Diffraction from the Deep Sea

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