HSQCD 2004

DGLAP

GLR

DPP

BFKL

Alan Martin (Durham)Repino, St. Petersburg18-22 May, 2004

Klempt

not a glueball

Glueballs, hybrids, pentaquarks

Klempt

Pentaquarks

Several expts see an exotic B=1, S=1baryon resonance in K+n or K0p channels(1530) with narrow width <10 MeV

The chiral soliton model (SM) predicted s(1530)with <15 MeV, JP=(1/2)+ in a 10 of SU(3)f

Praszalowicz(1987), Diakonov,Petrov,Polyakov(1997)

s(1530)

N

NA49 see(1860) which is not seen by ZEUS & WA89

seen by manyexpts in K+n, K0p

Popov

HERMES

but is s(1530)seen by H1 ??

Hyarapetian

1.5 MeV now expected from SM --- Petrov

Kubantsev

Petrov

Bag model fails for +(uudds)

Need new degree of freedom:

diquark ? -------CQMJaffe-Wilczek (ud)2 sKarliner-Lipkin (ud)(uds)…..but needs diquark in P-wave, many problems,always predicts too heavy + e.g. Narodetskii

is lightest degree of freedom ----- SM

s(1530)

N

Polyakovis the N*(1710) in the 10 ?

considers mixing with octet pp* / nn* ~ 0 by U-spin ~ 10-20 MeV

N PWA: N* could be P11(1680 or 1730)

N 2 MeV 5 MeVN 3 MeV

Petrov considersmixing with theRoper octet

Klempt

1577 ?

SM predicts 27 with I=1 KN multiplet -- but K+p partner not seen

H1 see c

which is not seen by ZEUS ?

Buschhorn

bb prod: latest data and theory in satisfactory agreement

Hadron spectroscopy is on the boil.

Changes almost daily.

Very exciting and experimentally confusing.

low x

Rostovsev

Fixed target DIS ep, ed, N; D-Yan, W asym, Tevatron jetsHERA epglobal DGLAP parton analyses CTEQ, MRSTanalyses to selected data sets Botje, Alekhin, ZEUS, H1…

Expect small x processesto be driven by the gluon.

Surprise at v.low scales appear to be dominated byby singlet sea quarks valence-like or -ve gluon !

Sea quarks & gluons not(perturbatively) connected.

x

1993

(Lum=20 nb-1)

Now

F2 versus x

Reg

ge

conf

inem

ent

BF

KL

DGLAP

ln Q2

ln 1/x

saturatio

n

absorptive corr.

HERA

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 includeselection of data fitted; choice of x,Q2,W2 cutsTheoretical uncertaintieshigher-order DGLAP NLO, NNLO…Moch,Vermaseren,Vogtsln(1/x) and sln(1-x) effects absorptive corrections from parton recombinationresidual higher-twist effectsQED effectsUncertainties due to input assumptionsisospin-violating effects MRSTs not equal to s CTEQheavy-target correctionschoice of input parametrization

no NuTeV sin2 anomaly

Alwall

Kotikov

MRST NNLO suggests W or Z prod. can bebe used as a luminosity monitorat the Tevatron (& LHC)

Kataev Gottfried sum rule in the large Nc limit

IG = (dx/x) (F2p – F2

n) = 0.235 +/- 0.026 expt.

= 1/3 - 2/3 dx (d – u)

valence:pert. corr. small,higher twist small s/Nc

2

(i)checks from Adler SR.(ii) 3-loop anom. dim. of MVV (NNLO) confirms colour structure

non-pert asymmetryof sea.what happens as x0? (SM)

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/ at HERA g2 x ~ 10-3 need to improve theory

(+ momentum sum rule)

ZeitnitzInclusive jets

Top quark cross section

Run I

Run II

3 jets/2 jets

inclusive jethelps pin downgluon at x~0.1

Savin &Rostovtsev

Extremely valuable if HERA could measure FL with sufficient precision --- to pindown the low x gluon

FL

Thorne

Q2=10

Q2=5

Q2=20 Q2=40Data are Klein’ssimulation basedon runs at Ep =400,465,575,920GeV.

DGLAP

ln 1/x resum ?abs. corr. ?

Higgs

Stirling

Lipatov

What happens to the Pomeron traj. at high temp.?

Remarkably -- nothing happens for fixed s.

-- result of conformal inv. of the original theory.

Running s destroys inv. – no exact solution –expect some change

May be possible to establish relation betweenBFKL and string dynamics –dimensions of space-time = no. of t ch. gluons?

Gluon kt distribution in resummed NLL BFKL

y=6

y=4

y=2

LO BFKL

NLL BFKL

DGLAP, DLLA

Final kt=30 GeV at y=ln(1/x)=8

Gluon kt along evolutionchain --- find thatNLL BFKL and DGLAPv.similar

Important sinceunderlying eventmight have maskedNew Physics signalsat LHC.

Monte Carlos OK

Ryskin

Diffractive DIS data Mastroberardino

Schildknecht:Also describes F2, F2

D,vector meson prod.well, using dipole approach with GVMD,incorporating saturation

mq=0

mq=140 MeV

Original Golec-Biernat, Wusthoff fit

Include charm.

Relate to xg &evolve in Q2

+Bartels,Kowalski

Is it saturation orconfinement ?

There are other dipole fits withoutsaturatione.g. Forshaw,Kerley & Shaw.

Saturation

No definitive experimental evidence

Much theoretical activity -----BK, JIMWLK,…equations

A glimpse…

Rostovsev

Equivalent approaches

p rest frame / fast dipole fast p / slow dipole

bare dipole

evolved pwave fn.(cgc)

wave fn.

Balitsky Kovchegov eq.

Jalilan Marian, Iancu, McLerran,Weigert, Leonidov, Kovner eq.

leads to

Lublinsky explained this muchbetter

Fadin

Bartels

Two progress reports:

is proving that gluon Reggeization is valid at NLO BFKL

Checking the consistency of bootstrap relations, s ch.unitarity and Reggeization for production amplitudes.

is relating the BK equation to Reggeon field theory

Remarkable simplifications from Mobius invariance

Saturation momentum Qs(x) in NLL BFKL ~ DGLAP

x0 defined byQs(x0)=1 GeV

Ryskin

LO BFKLunreliable,BK,JIMWLKeqs. ?!

Qs2

x0/x

Nikolaev

Saturation effects in nuclei.

Diffractive DIS is about 50% in nuclei.

Collective nuclear glue (nuclear Pomeron) is agood idea but destroys kT factorization. Also fan diagrams no longer sufficient.

Diffractive DIS data Mastroberardino

Mastroberardino

Mastroberardino

Mastroberardino

ln Q2

highertwist

Bartels,Ellis,Kowalski & Wusthoffbase parametrizationon these forms

Contribution of diffractive F2 to inclusive F2

Apply the AGK cutting rules to contrib.AGK in QCD: Bartels & Ryskin

F2abs ~ - F2

D negative (~Glauber shadowing)

In pQCD, is a cut, not a pole Lipatov

has a continuous no. of compts of different size, r~1/For eachcompt., DGLAP evol. of F2

D(x,Q2,2) starts from Q

provided it is large enough

Im Tel ~ tot

Ryskin

Ryskin

Input ~ MRST2001

Ryskin

Ryskin

xg, xS const

Ryskin

Need Q2 Q2+1mimics power corr.

rapidity gap survival factor S2 ~ 0.1

HERA

S2 ~ 1

*

Survival factors calc. from2-ch eikonal model basedon multi-Pom. exchange &s channel unitarity KKMR

Diffractive photoproduction of dijets: direct compt. S2 ~ 1 resolved compt. (hadron-like) S2 ~ 0.34

NLO analysis byKlasen & Kramer,--good agreementwith prelim. H1 data

Note in LO analysis,data would prefer S2 ~ 1 for resolved

Mastroberardino

Exclusive diffractive Higgs signal pp p+H+p

Higgs

For a 120 GeV (SM) Higgsat the LHC (L=30 fb-1)11 events / 4 backgroundFor MSSM with tan~50, mA~130 GeV70 events / 3 background

Advantages: 2 indep. MH det.1. missing mass to proton taggers (M~1 GeV)2. bb decay (M~10 GeV)

bb backgd v.suppressed by Jz=0 selection rule

S2 = 0.026

Khoze

5signal at LHC

30 fb-1

300 fb-1

Khoze

Kim, Schlein

Higgs via single Pomeron exchange

Predicted much larger signal, but

---need to study of background,---include evolution from Q2=50 GeV2 (UA8) up toQ2=104 GeV2

Amarian Semi-inclusive ep eX HERMES

Sidorov

Sidorov

Ochs

Ng/Nq = CF/CA = 9/4 -- naïve

MLLA -- better agreement with e+e- data

Full calculation – excellent agreement parameter determined from multiplicity

Pivovarov

Calculated the B parameter at NLO --- three loopnon-factorising massive Feynman graph B = 1 + 0.095 - 0.05 pert. nonpert.

Apologies omitting for so many excellent contributions

There are so many crucial measurements still tobe done, and unless the correct action is set intomotion soon, time will run out for HERA ---while the physics potential of the machine is stillcoming to its prime.

Buschhorn

Very special thanks toPetersburg Nuclear Physics InstitutePetersburg branch of the RASPetersburg State UniversityFock Institute of PhysicsStaff of the Baltiets Hotel

AssistantsPavel YakimovJulia GrebenyukNastya GrebenyukSergey AnufrievSergey Afonin

Foreign departmentTatiana BondarenkoNatalia Nikitina

DriversSergey ZvonovskyEduard PatsyukovDima Dzyubchuk

PhotographerTatiana Potapova

Social ProgrammeLyudmila Kolesnikova

SecretariatGalina StepanovaZoya GaditskayaLidia RusinovaTatiana Gordeeva

Victor GordeevVictor KimLev Lipatov

…and to ALL the participants for making this sucha productive and enjoyable meeting

…and so on to HSQCD 2005