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HSQCD 2004

HSQCD 2004. BFKL. DGLAP. DPP. GLR. Alan Martin (Durham) Repino, St. Petersburg 18-22 May, 2004. Glueballs, hybrids, pentaquarks. Klempt. not a glueball. Klempt. Pentaquarks. Several expts see an exotic B=1, S=1 baryon resonance in K + n or K 0 p channel

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HSQCD 2004

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  1. HSQCD 2004 BFKL DGLAP DPP GLR Alan Martin (Durham) Repino, St. Petersburg 18-22 May, 2004

  2. Glueballs, hybrids, pentaquarks Klempt not a glueball

  3. Klempt

  4. Pentaquarks Several expts see an exotic B=1, S=1 baryon resonance in K+n or K0p channel Qs(1530) with narrow width G<10 MeV

  5. The chiral soliton model (cSM) predicted Qs(1530) with G<15 MeV, JP=(1/2)+ in a 10 of SU(3)f Praszalowicz(1987), Diakonov,Petrov,Polyakov(1997) seen by many expts in K+n, K0p Qs(1530) N S X X-- NA49 see X(1860) which is not seen by ZEUS & WA89

  6. Popov

  7. HERMES Hyarapetian but is Qs(1530) seen by H1 ??

  8. Kubantsev 1.5 MeV now expected from cSM --- Petrov

  9. Petrov Bag model fails for Q+(uudds) Need new degree of freedom: diquark ? -------CQM Jaffe-Wilczek (ud)2 s Karliner-Lipkin (ud)(uds) …..but needs diquark in P-wave, many problems, always predicts too heavy Q+ e.g. Narodetskii p is lightest degree of freedom ----- cSM

  10. Polyakov is the N*(1710) in the 10 ? considers mixing with octet gpp* / gnn* ~ 0 by U-spin G(N*) ~ 10-20 MeV Qs(1530) pN 2 MeV pD 5 MeV hN 3 MeV N S Petrov considers mixing with the Roper octet X pN PWA: N* could be P11(1680 or 1730)

  11. Klempt

  12. 1577 ? cSM predicts 27 with I=1 KN multiplet -- but K+p partner not seen

  13. H1 see Qc Buschhorn which is not seen by ZEUS ? bb prod: latest data and theory in satisfactory agreement

  14. Hadron spectroscopy is on the boil. Changes almost daily. Very exciting and experimentally confusing.

  15. Rostovsev low x

  16. Fixed target DIS ep, ed, nN; D-Yan, W asym, Tevatron jets • HERA ep • global DGLAP parton analyses CTEQ, MRST • analyses to selected data sets Botje, Alekhin, ZEUS, H1… Expect small x processes to be driven by the gluon. Surprise at v.low scales appear to be dominated by by singlet sea quarks  valence-like or -ve gluon ! Sea quarks & gluons not (perturbatively) connected.

  17. x

  18. F2 versus x Now 1993 (Lum=20 nb-1)

  19. ln 1/x saturation absorptive corr. Regge confinement HERA BFKL DGLAP ln Q2

  20. HERA has opened up the small x domain • how large is the DGLAP domain ? • are BFKL (log 1/x) effects evident ? • is there any evidence of absorptive corrections, or even parton saturation ? • HERA observes diffractive DIS (at ~10% of DIS). What role does it play ? • what would we like HERA to measure now ?

  21. CTEQ gluon compared to MRST error band Q2=5 Q2=100

  22. Parton uncertainties due to stat/sym errors of data fitted Other uncertainties include selection of data fitted; choice of x,Q2,W2 cuts Theoretical uncertainties higher-order DGLAP NLO, NNLO…Moch,Vermaseren,Vogt asln(1/x) and asln(1-x) effects absorptive corrections from parton recombination residual higher-twist effects QED effects Uncertainties due to input assumptions isospin-violating effects MRST s not equal to s CTEQ heavy-target corrections choice of input parametrization Kotikov no NuTeV sin2q anomaly Alwall

  23. suggests W or Z prod. can be be used as a luminosity monitor at the Tevatron (& LHC) MRST NNLO

  24. Kataev Gottfried sum rule in the large Nc limit (dx/x) (F2mp – F2mn) = 0.235 +/- 0.026 expt. IG = dx (d – u) = 1/3 - 2/3 non-pert asymmetry of sea. what happens as x0? (cSM) valence: pert. corr. small, higher twist small as/Nc2 (i)checks from Adler SR. (ii) 3-loop anom. dim. of MVV (NNLO) confirms colour structure

  25. Experimental ways to determine the gluon • FL most direct x ~ 10-4 - 10-3 • Prompt photon data (WA70,E706) and theory problems • Tevatron jets x ~ 0.07 – 0.5 • HERA jets x ~ 0.01 - 0.1 (ZEUS) • Diffractive J/y at HERA g2x ~ 10-3 need to improve theory (+ momentum sum rule)

  26. Inclusive jets Zeitnitz Top quark cross section Run I Run II

  27. Savin & Rostovtsev inclusive jet helps pin down gluon at x~0.1 3 jets/2 jets

  28. FL Q2=10 Q2=5 Extremely valuable if HERA could measure FL with sufficient precision --- to pin down the low x gluon Data are Klein’s simulation based on runs at Ep = 400,465,575,920 GeV. Q2=20 Q2=40 Thorne

  29. Stirling Higgs DGLAP ln 1/x resum ? abs. corr. ?

  30. Lipatov What happens to the Pomeron traj. at high temp.? Remarkably -- nothing happens for fixed as. -- result of conformal inv. of the original theory. Running as destroys inv. – no exact solution – expect some change May be possible to establish relation between BFKL and string dynamics – dimensions of space-time = no. of t ch. gluons?

  31. Gluon kt distribution in resummed NLL BFKL Ryskin Gluon kt along evolution chain --- find that NLL BFKL and DGLAP v.similar Important since underlying event might have masked New Physics signals at LHC. Monte Carlos OK Final kt=30 GeV at y=ln(1/x)=8 LO BFKL DGLAP, DLLA NLL BFKL y=4 y=6 y=2

  32. Mastroberardino Diffractive DIS data

  33. Schildknecht: Also describes F2, F2D, vector meson prod. well, using dipole approach with GVMD, incorporating saturation

  34. Original Golec-Biernat, Wusthoff fit Include charm. Relate to xg & evolve in Q2 +Bartels,Kowalski Is it saturation or confinement ? There are other dipole fits without saturation e.g. Forshaw, Kerley & Shaw. mq=0 mq=140 MeV

  35. Saturation No definitive experimental evidence Rostovsev Much theoretical activity ----- BK, JIMWLK,…equations A glimpse…

  36. Equivalent approaches p rest frame / fast dipole fast p / slow dipole bare dipole evolved p wave fn. (cgc) • wave fn. Balitsky Kovchegov eq. Lublinsky explained this much better leads to Jalilan Marian, Iancu, McLerran, Weigert, Leonidov, Kovner eq.

  37. Two progress reports: Fadin is proving that gluon Reggeization is valid at NLO BFKL Checking the consistency of bootstrap relations, s ch. unitarity and Reggeization for production amplitudes. Bartels is relating the BK equation to Reggeon field theory Remarkable simplifications from Mobius invariance

  38. Saturation momentum Qs(x) in NLL BFKL ~ DGLAP Ryskin Qs2 LO BFKL unreliable, BK,JIMWLK eqs. ?! x0 defined by Qs(x0)=1 GeV x0/x

  39. Nikolaev Saturation effects in nuclei. Diffractive DIS is about 50% in nuclei. Collective nuclear glue (nuclear Pomeron) is a good idea but destroys kT factorization. Also fan diagrams no longer sufficient.

  40. Diffractive DIS data Mastroberardino

  41. Mastroberardino

  42. Mastroberardino

  43. Mastroberardino

  44. higher twist ln Q2 Bartels,Ellis, Kowalski & Wusthoff base parametrization on these forms

  45. I I I I P P P P Ryskin Contribution of diffractive F2 to inclusive F2 Apply the AGK cutting rules to contrib. AGK in QCD: Bartels & Ryskin Im Tel ~ stot DF2abs ~ - F2D negative (~Glauber shadowing) In pQCD, is a cut, not a pole Lipatov has a continuous no. of compts of different size, r~1/m For eachcompt., DGLAP evol. of F2D(x,Q2,m2) starts from m Q provided it is large enough

  46. Ryskin

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