Tev4LHC @ BNL 3-5 Feb 2005Diffraction from CDF2LHC K. Goulianos1 Diffraction from CDF2LHC K. Goulianos Tev4LHC 3-5 February 2005 Brookhaven National Laboratory

$Page 1: Tev4LHC @ BNL 3-5 Feb 2005Diffraction from CDF2LHC K. Goulianos1 Diffraction from CDF2LHC K. Goulianos Tev4LHC 3-5 February 2005 Brookhaven National Laboratory$
Tev4LHC @ BNL 3-5 Feb 2005

Diffraction from CDF2LHC K. Goulianos 1

Diffraction from CDF2LHC

K. Goulianos

Tev4LHC3-5 February 2005

Brookhaven National Laboratory



What is Dark Energy?

* * ** * *

H He

E

M

* * ** * *

H He

E

M



Rapidity Gaps

Gaps are exponentially suppressed

From Poisson statistics:

dy

dneyP y )(

(=particle density in rapidity space)

Rapidity gaps are formed bymultiplicity fluctuations.

Non-diffractive interactions

Bj, PRD 47 (1993) 101: regions of (pdeudo)rapidity devoid of particles

ε122

0t M

1~

dM

dσΔy2εe~Δyd

dσ

2lnlnln Msy

Rapidity gaps at t=0 grow with y.Diffractive interactions

pp /

2: negative particle density!



CDF Run I results

93(2004)141601

http://physics.rockefeller.edu/dino/my.html



valence quarks

antiproton

x=

Single Diffraction

proton

)or(1

)( xxfx

g=0.20

q=0. 04

R=-0.5

g=0.5

q=0.3

SOFT HARD

deep sea

Derive diffractivefrom inclusive PDFsand color factors

antiproton

valence quarks

p

p



Inclusive Single Diffraction

Unitarity problem: Using factorization and std pomeron flux SD exceeds T at Renormalization: normalize the Pomeron flux to unity

)(Mσξ)(t,fdtdξ

σd 2XpIPIP/p

SD2

KG, PLB 358 (1995) 379

TeV.2s

1dtdξξ)(t,f0.1

ξ

IP/p

0

tmin

2~ sSD



A Scaling Law in Diffraction

KG&JM, PRD 59 (1999) 114017

Factorization breaksdown in favor of

M2-scaling

12

2

2 )(M

s

dM

d

renormalization

1



Elastic and Total Cross Sections

ytel etsf ),(Im

y sy ln

The exponential rise of T(y’) is dueto the increase of wee partons with y’

(see E. Levin, An Introduction to Pomerons,Preprint DESY 98-120)

yooT ess )(

y sy ln

QCD expectations

Total cross section:power law rise with energy

Elastic cross section:forward scattering amplitude

s



Soft Diffraction

yy

yt ,2 independent variables:

yo

ytp eetFC

yddt

d

222

)(

gap probability

Renormalization removes the s-dependence SCALING

ye 2~ 22ln

minsydyssy

y

t

colorfactor

17.0)0(

)(

ppIP

IPIPIP tg

(KG, hep-ph/0205141)

sub-energy x-section



The Factors and Experimentally: KG&JM, PRD 59 (114017) 1999

g=0.20

q=0.04

R=-0.5

fg=gluon fractionfq=quark fraction

λx

1f(x)x

18.03

125.0

8

175.0

121f

1

1f

2

Q

NN cq

cgColor factor:

12.0ww qqgg Pomeron intercept:

104.0,02.017.0

pIP

IPIPIPg

λ

/sxs~dxxf

1

1)(

CTEQ5L



Multigap Diffraction

ye 2~ 22ln

minsyssy

y

Same suppressionas for single gap!

2122

2-1i1

2

51

5

)( yyo

ytp

ii

eetFCdV

dii

Gap probability Sub-energy cross section(for regions with particles)

1y 2y1y 2y

1y 2y

1t 21 yyy 5 independent variables2t color

factors

(KG, hep-ph/0205141)



Central and Two-Gap CDF Results

One-gap cross sections are suppressed Two-gap/one-gap ratios are 17.0

Differential shapes agree with Regge predictions

DD SDD DPE



Gap Survival Probability

0.23GeV)(1800S gapgap/01gapgap/12

0.29GeV)(630S gapgap/01gapgap/12

S =

Results similar to predictions by:Gotsman-Levin-MaorKaidalov-Khoze-Martin-RyskinSoft color interactions



Diffractive DIS @ HERA

),(1

),,( 221

2)3(2 QQ xFxF D

eQ2*

p

jet

reorganize

Factorization holds: J. Collins

e*

tp

IP

Pomeron exchange Color reorganization



Inclusive vs Diffractive DIS

CCF

Q

QQD

1212)3(

2

1

)()(

)(1),,(

2

P(0)-1(q)/2

F2 ~ x

q

KG, “Diffraction: a New Approach,” J.Phys.G26:716-720,2000 e-Print Archive: hep-ph/0001092



diff/incl DIS at HERA

At fixed x:flat Q2-dependence

At fixed Q2:flat x-dependence



Diffractive Dijets @ Tevatron

),/(1

),,( 22

21 QQ xFxF D

pjet

reorganizep

jet



FDJJ(,Q2) @ Tevatron

C

sx

CF

Q

QQD

2122111

)/(

)(1),,(

)(

22

2

εε

2sβ

1~

β

xξ1

ξ 211

renorm sβξ

dξN

minmin

min

)2(

)(1

121

~R2

RENORM

x

QsxSD

ND

4.02.0 xg



SD/ND Dijet Ratio vs xBj@ CDF

(x)F

(x)FR(x) ND

jj

SDjj

0.035 < < 0.095

Flat dependence



Tevatron vs HERA:Factorization Breakdown

dN/dgap dN/dgap

p

ppIP

CDF

H1

p

ppIP

e*

tp

IP

Predicted in KG, PLB 358 (1995) 379



New: FDJJ() from ZEUS-LPS Data

Fit includingcharm data

Fit withoutcharm data

ZEUS

H1

M. Arneodo, HERA/LHC workshop, CERN, 11-13 Oct 2004

Flat after subtractingReggeon contribution



Restoring Factorization @ Tevatron

R(SD/ND)

R(DPE/SD)DSF from two/one gap:factorization restored!



CDF2LHC

TOPIC STATUS

(Q2, t) dependence of DSF close to ready

Exclusive c production close to ready

Low mass states in DPE need good trigger

Exclusive b-bbar production in DPE need b-trigger

-dependence of DSF need low lum run

Jet-gap-Jet w/jets in miniplugs need low lum run

compositeΔyΔy

BFKLΔyΔyjetgap

jetgap

gapΔyjetΔy



Diffraction @ LHC

Multigap diffraction

Exclusive production of high mass states



Summary

@CDF Derive diffractive from ND pdf’s and color factors@ LHC Multigap and High Mass Exclusive DiffractionCDF2LHC Special low-lum run needed for low- and JGJ

Documents

Tev4LHC @ BNL 3-5 Feb 2005Diffraction from CDF2LHC K. Goulianos1 Diffraction from CDF2LHC K. Goulianos Tev4LHC 3-5 February 2005 Brookhaven National Laboratory