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 BFKL DGLAP DPP GLR Alan Martin (Durham) Repino, St. Petersburg 18-22 May, 2004
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
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
Kubantsev 1.5 MeV now expected from cSM --- Petrov
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
Polyakov is the N*(1710) in the 10 ? considers mixing with octet gpp* / gnn* ~ 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)
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.
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 ?
CTEQ gluon compared to MRST error band Q2=5 Q2=100
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
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 x0? (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
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)
Inclusive jets Zeitnitz Top quark cross section Run I Run II
Savin & Rostovtsev inclusive jet helps pin down gluon at x~0.1 3 jets/2 jets
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
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?
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
Schildknecht: Also describes F2, F2D, vector meson prod. well, using dipole approach with GVMD, incorporating saturation
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
Saturation No definitive experimental evidence Rostovsev Much theoretical activity ----- BK, JIMWLK,…equations A glimpse…
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.
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
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.
higher twist ln Q2 Bartels,Ellis, Kowalski & Wusthoff base parametrization on these forms
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