Massimo Corradi - file- Azimuthal Asymmetries in NC DIS - Search for Stop in Rp-violating SUSY - Open Beauty in the D - Final State - Rapidity Gaps Between Jets in PhP - K0 S and Production

Preview of ZEUS Results

Massimo Corradi

INFN Bologna

Hamburg University von Humboldt Fellow

DIS 2007, Munchen, 16 April 2007

0 M. Corradi ZEUS Preview

Luminosity

HERA delivered

0

100

200

300

400

500

0 200 400 600 800 1000 1200 1400days of running

Inte

gra

ted

Lu

min

osi

ty (

pb

-1)

days of running

Inte

gra

ted

Lu

min

osi

ty (

pb

-1)

Switch e−p→ e+p in June 2006

High Energy Running (HER)(√s = 300 − 320GeV)

ended on March 20, 2007

Total HER luminosity delivered by HERA1993-2007: L = 758 pb−1

Low Energy Running (LER)(√s = 225GeV)

ongoing, 3 pb−1 up to now...

End of HERA on July 2nd

Useful physics luminosity collected by ZEUS:period e+p e−pHERA-I 115 pb−1 17 pb−1

HERA-II (polarised) 182 pb−1 190 pb−1

Total 297 pb−1 207 pb−1

Total ZEUS physics luminosityL=0.50 fb−1


New ZEUS results since DIS2006

Publications- NC DIS at High Bjorken-x- Prompt Photons plus Jets in PhP- Inclusive-jets and Dijets in DIS- Azimuthal Asymmetries in NC DIS- Search for Stop in Rp-violating SUSY- Open Beauty in the D∗-µ Final State- Rapidity Gaps Between Jets in PhP- K0

S and Λ Production in DIS and PhP- Jet Radius Dependence of Incl.-jet Cross-sections- Leading Neutron E and PT in DIS and PhP- D∗± Production at low Q2

- Diffractive PhP of D∗±

New Final results for DIS07(paper soon)- Diffractive Dijet PhP- Forward Jets- Multijets at Low x- D Mesons in DIS- p, p, d, d in DIS- Bose-Einstein correl. of Kaons

Preliminary results- Contact Interactions- Isolated leptons- D∗ in DIS- Inelastic J/ψ Helicity- σb from µµ- inclusive diffraction- scaled momentum distributions

New Prel. results for DIS07- F b

2, Fc2 from D∗

- NC DIS with polarised e−

- Multieleptons- Jets in CC DIS- Dijets in NC DIS- D+ in DIS- D∗ fragmentation- DIS at high-y- Exclusive ρ in DIS- High-ET Dijets in PhP

In red the results mentioned here


Neutral currents with polarised e−

Full polarised e− sample: LR=72 pb−1, PR = +0.30; LL=105 pb−1, PL = -0.27

ZEUS

0.20.40.60.8

11.2

2 = 200 GeV2Q

0.20.40.60.8

11.2

2 = 650 GeV2Q

0.20.40.60.8

11.2 2 = 2000 GeV2Q

-210 -1100

0.20.40.60.8

11.2 2 = 12000 GeV2Q

2 = 250 GeV2Q

2 = 800 GeV2Q2 = 3000 GeV2Q

-210 -110

2 = 20000 GeV2Q

2 = 350 GeV2Q

2 = 1200 GeV2Q2 = 5000 GeV2Q

-210 -110

2 = 30000 GeV2Q

x

2 = 450 GeV2Q

2 = 1500 GeV2Q2 = 8000 GeV2Q

p- ZEUS NC (prel.) e

)-1 = +0.37 (72 pbe P

SM (ZEUS-JETS)

)-1 = -0.27 (105 pbe P

SM (ZEUS-JETS)

σ~

Difference between L/R-handed crosssection due to γZ interference:

σ(e−Lp)−σ(e−Rp) ∼ 2F P2 ' 2

∑

(q+q)2eqaevqχZ

(χZ = Q2

Q2+M 2Z

1sin2 2θW

)

sensitivity to vector coupling of u, d to Z0

ZEUS

)2 (GeV2Q310 410

Asy

mm

etry

-0.8

-0.6

-0.4

-0.2

-0

0.2

ZEUS NC (prel.)

)-1p (177 pb-e

SM (ZEUS-JETS)

= -0.27e = +0.30 / PeP

A =2

PR − PL

σ(PR) − σ(PL)

σ(PR) + σ(PL)


Combined H1, ZEUS, e−p and e+p

Improve significance on Acombining H1 and ZEUS,e+p and e−p

A± = A(e±p)

Status of ICHEP06Total H1+ZEUS Lumi 478 pb−1

Parity violation in NC at high Q2

clearly established

P (χ2 ≥ χ2(data)|A+ = A−) = 0.003

.

e+

e−

HERA

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

103

104

Q2 (GeV2)

A

H1+ZEUS Combined (prel.)

A+

A-

H1 2000 PDFZEUS-JETS PDF


Neutral Currents e−p vs e+p, F3

ZEUS

0.20.40.60.8

11.2

2 = 200 GeV2Q

0.20.40.60.8

11.2

2 = 650 GeV2Q

0.20.40.60.8

11.2 2 = 2000 GeV2Q

-210 -1100

0.20.40.60.8

11.2 2 = 12000 GeV2Q

2 = 250 GeV2Q

2 = 800 GeV2Q2 = 3000 GeV2Q

-210 -110

2 = 20000 GeV2Q

2 = 350 GeV2Q

2 = 1200 GeV2Q2 = 5000 GeV2Q

-210 -110

2 = 30000 GeV2Q

x

2 = 450 GeV2Q

2 = 1500 GeV2Q2 = 8000 GeV2Q

ZEUS NC (prel.) = 0)

e, P-1p (177 pb- e

SM (ZEUS-JETS)

ZEUS NC= 0)

e , P-1p (63.2 pb+ e

SM (ZEUS-JETS)

σ~

e−p,corrected to Pe ∼ 0e+p unpolarised from HERA-I

σ(e+p) − σ(e−p) = 2Y −

Y +xF3

' 2Y −

Y +

∑

(q − q)2eqaqaeχZ

sensitivity to axial coupling of u, d to Z0

ZEUS

3xF

-0.1

0

0.1

0.2

2 = 3000 GeV2Q

-110 1

-0.1

0

0.1

0.2

2 = 12000 GeV2Q

2 = 5000 GeV2Q

-110 1

2 = 20000 GeV2Q

2 = 8000 GeV2Q

-110 1

2 = 30000 GeV2Q

ZEUS NC (prel.))-1p (240 pb± e

SM (ZEUS-JETS)

x

Valence distribution from pure p target5 M. Corradi ZEUS Preview

Limits on new physicsCompare NC DIS with SM to search for new contributions to the eq → eq amplitude:Contact Interactions, Large Extra Dimensions, quark substructure

Combined HERA-I and HERA-II-pol.L= 274 pb−1

Quark radius

dσ

dQ2=

(

dσ

dQ2

)

SM

(

1 − 1

6R2qQ

2

)2

Q2 (GeV2)

N/N

CT

EQ

5D

Quark Radius Limits

ZEUS PreliminaryZEUS 94-05 e±pRq

2 = (0.67 ⋅10-16cm)2

Rq2 = -(0.81 ⋅10-16cm)2

1

10

103

104

0.8

0.9

1

1.1

1.2

103

104

EW Quark radius (RMS)Rq < 0.67 × 10−3 fm (prel.)

Contact Interactions

LCI = 2πΛ

∑

α,β=L,R(qαγµqα)(eβγ

µeβ)

RR

RL

LR

LL

U6

U5

U4

U3

U2

U1

X6

X5

X4

X3

X2

X1

VA

AA

VV

-0.2 -0.1 0 0.1 0.2

±1/Λ2 (TeV-2)

ZEUS Preliminary

7.5 6.3

5.9 6.3

3.3 3.5

4.3 4.7

5.1 4.7

5.9 5.3

5.4 4.8

5.1 4.5

4.3 4.1

5.2 5.5

6.1 5.2

7.1 6.1

6.1 5.0

6.2 5.0

4.5 4.7

4.2 4.2

2.0 3.6

2.3 3.6

4.0 3.8

94-05 e±p-1/Λ2 best fit value +1/Λ2 best fit value

allowed ±1/Λ2 range

Λ− (TeV) Λ+ (TeV)

Limits on Λ for VV,AA ∼ 6-7.5 TeV


Multileptons

(GeV)12M0 50 100 150 200

Eve

nts

-210

-110

1

10

210ZEUS (prel.)

-1446 pbSMQEDC

NC

ZEUS

ee

(GeV)12M0 50 100 150 200

Eve

nts

-210

-110

1

10

ZEUS (prel.)

-1446 pb

SM

NC

ZEUS

eee

Multielectron analysis ⇑:ee: 2 central e with P 1,2

T > 10,5 GeV

eee: an additional e with E > 10GeV (5 in rear)

almost full luminosity (446 pb−1)good agreement with SM

electron+muon analysis (135 pb−1)=⇒:3 events, in agreement with 2 expected from τ τ

XY View ZR View


Isolated leptons and PmissT

Analysis of e+p data up to 2006(228 pb−1)

All e−p 98-06 (204 pb−1)

All in good agreement with SM

e+p

12 <PXT <25 GeV PX

T > 25 GeVData/SM (W) Data/SM (W)

e 98-06 e−p (204 pb−1) 6/2.9 ± 0.5 (56%) 5/3.8 ± 0.6 (55%)

e 96-06 e+p (228 pb−1) 4/2.8 ± 0.5 (63%) 1/3.2 ± 0.4 (75%)e 96-06 e±p (432 pb−1) 10/5.7 ± 0.7 (60%) 6/7.0 ± 0.7 (64%)

µ 98-06 e−p (204 pb−1) 2/2.2 ± 0.3 (68%) 2/2.2 ± 0.3 (86%)

µ 96-06 e+p (228 pb−1) 3/2.6 ± 0.5 (68%) 3/3.1 ± 0.5 (80%)µ 96-06 e±p (432 pb−1) 5/4.8 ± 0.5 (68%) 5/5.3 ± 0.6 (82%)


Inclusive Jets in Breit frame in DIS

- Inclusive jets in Breit frame directly sensitive to αs and g(x)Small theor. uncertainty (∼ 5%) at high ET and Q2

- all HERA-I data published, good agreement with NLO QCD

. Jet radius dependence extraction of αS

ZEUS 82 pb-1

NLO hadr Z0⊗ ⊗

jet energy scale uncertainty

NLO uncertainty

Q2 > 125 GeV2

EjetT,B > 8 GeV

-2 < ηBjet < 1.5

|cos γh| < 0.65

R

σ jets

(pb

)

0

200

400

0.4 0.5 0.6 0.7 0.8 0.9 1 1.1

NLO hadr Z0⊗ ⊗

NLO LO

R

σ jets

(pb

)

0

200

400

0.4 0.6 0.8 1

ZEUS

0.1

0.15

0.2

10 15 20 25 30 35 40 45

QCD(αs(MZ) = 0.1207 ± 0.0044)

ZEUS 82 pb-1

}th.} stat. } stat.+

syst.

EjetT,B (GeV)

αs

αS(MZ) = 0.1207 ± 0.0014(stat.) ± 0.0035(syst.) ± 0.0023(theo.)


Dijets in DIS

- HERA-I data published, extended to HERA-II 04-05 (209 pb−1)- Sensitivity to g(x) at large ξ

) (p

b)ξ(

10/d

log

σd

2

10

2030

2

10

20

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

2

10

20

had C⊗NLO (CTEQ6)

)-1ZEUS prel. (209 pb


)| < 0.65had

γ|cos(

> 12(8) GeVjet1(2)T,BreitE

< 1.5jet

Breitη-2 <

2

TE+2=QR2µ

2=QR2µ

2

TE=R2µ

2 < 250 GeV2125 < Q 2 < 500 GeV2250 < Q

2 < 1000 GeV2500 < Q 2 < 2000 GeV21000 < Q

2 < 5000 GeV22000 < Q

ZEUS

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

)2 T

E+2

=Q2 Rµ

rel.

diff

. to

NL

O (

-0.5

0

0.5

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

-0.5

0

0.5

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

)ξ(10

log-1.8 -1.6 -1.4 -1.2 -1 -0.8

-0.5

0

0.5

had C⊗NLO (CTEQ6)

)-1ZEUS prel. (209 pbNLO uncertaintyjet energy scale uncertainty

)| < 0.65had

γ|cos(

> 12(8) GeVjet1(2)T,BreitE

< 1.5jet

Breitη-2 <

2=QR2µ

2

TE=R2µ

2 < 250 GeV2125 < Q 2 < 500 GeV2250 < Q

2 < 1000 GeV2500 < Q 2 < 2000 GeV21000 < Q

2 < 5000 GeV22000 < Q

ZEUS


Jet in Charged Current DIS

L=180 pb−1 04-06 e−p

Inclusive jets Dijets Trijets

ZEUS

10-2

10-1

1

20 40 60 80 100 120

ZEUS CC e-p (prel.) 180 pb-1

CDM

Q2 > 200 GeV2

y < 0.9

-1 < ηjet < 2.5

inclusive jets


ETjet (GeV)

dσ/

dETje

t (pb

/GeV

)

-0.4

-0.2

0

0.2

0.4

20 40 60 80 100 120 ET

jet (GeV)

rel.

diff

. to

CD

M

ZEUS

10-3

10-2

10-1

1

20 40 60 80 100 120


CDM x 1.33

Q2 > 200 GeV2

y < 0.9

Ejet1

T (Ejet2

T ) > 14 (5) GeV

-1 < ηjet < 2.5

dijets


Mjj (GeV)

dσ/

dMjj (

GeV

/pb)

0

1

2

20 40 60 80 100 120 Mjj (GeV)

rel.

diff

. to

CD

M

ZEUS

10-3

10-2

10-1

20 40 60 80 100 120


CDM x 1.52

Q2 > 200 GeV2

y < 0.9

-1 < ηjet < 2.5

Ejet1

T > 14 GeV

Ejet2

T > 5 GeV

Ejet3

T > 5 GeV

three jets


M3j (GeV)

dσ/

dM3j

(G

eV/p

b)

-0.5

0

0.5

1

20 40 60 80 100 120 M3j (GeV)

rel.

diff

. to

CD

M

Compared at the moment to MC (Ariadne), NLO coming soon


High ET dijets in photoproduction

Ej1,j2T > 20,15 GeV,

−1 < ηj < 3

(at least one with −1 < ηj < 2.5)

well described by NLO QCD

sensitive to g(x) in γ and p

obsγx

(p

b)

ob

sγ

/dx

σd

0

200

400

600

800

1000

1200

1400 -1ZEUS (prel.) 81.8 pb

HAD⊗NLO (AFG04 & CTEQ5M1)

HAD⊗NLO (CJK & CTEQ5M1)

HAD⊗NLO (AFG & CTEQ5M1)

HAD⊗NLO (GRV & CTEQ5M1)

HAD⊗NLO (SAL & CTEQ5M1)

Jet ES uncertainty

obsγx

(p

b)

ob

sγ

/dx

σd

0

200

400

600

800

1000

1200

1400

obsγx

0.2 0.4 0.6 0.8 1Rat

io t

o A

FG

04

0.81

1.21.41.6

obsγx

0.2 0.4 0.6 0.8 1Rat

io t

o A

FG

04

0.81

1.21.41.6

(GeV)TE

(p

b/G

eV)

TE

/dσd

-210

-110

1

10

-1ZEUS (prel.) 81.8 pb

HAD⊗NLO (AFG04)

HAD⊗NLO (CJK)

HAD⊗NLO (AFG)

HAD⊗NLO (GRV)

HAD⊗NLO (SAL)

Jet ES uncertainty

(GeV)TE

(p

b/G

eV)

TE

/dσd

-210

-110

1

10

(GeV)TE20 30 40 50 60 70R

atio

to

AF

G04

0.5

1

1.5

(GeV)TE20 30 40 50 60 70R

atio

to

AF

G04

0.5

1

1.5


Jets at low-x.Is standard QCD based on collinear factorization +DGLAP working at low-x for forward and multiple jets?

- Forward jets , range extended to η = 4.3

agree with fixed-order QCD O(α2S)

⇑ forward jet cross section forEjT > 5GeV; xj > 0.036; 0.5 < (Ej

T )2/Q2 < 2;

20 < Q2 < 100GeV2, 4× 10−4 < x < 5 × 10−2

Two and three jets at low-x ,

agreement with O(α3S) calculations

⇑ cross section for unbalanced dijets:∆Φ < 120o

for Ej1,2T,HCM > 7,5GeV, −1 < ηLAB < 2.5


Charm production in DIS

New measurements of charm in DISwith different techniques:

1) combined D±,D0,Ds from HERA-I

2)

M (GeV)∆0.14 0.15 0.16

Co

mb

inat

ion

s

0

500

1000

1500

2000

M (GeV)∆0.14 0.15 0.16

Co

mb

inat

ion

s

0

500

1000

1500

2000-1ZEUS (prel.) 162 pb

Wrong-charge Background

Fit 148±N(D*) = 5898 D∗± (prel.)

162 pb−1

HERA-II

3)

) (GeV)ππM(K1.7 1.75 1.8 1.85 1.9 1.95 2 2.05 2.1

Co

mb

inat

ion

s / 1

0 M

eV

0

100

200

300

400

500

600

700

800

900

1000ZEUS

) (GeV)ππM(K1.7 1.75 1.8 1.85 1.9 1.95 2 2.05 2.1

Co

mb

inat

ion

s / 1

0 M

eV

0

100

200

300

400

500

600

700

800

900

1000

+ X± e + D→ep

83±): 2181 ±N(D

> 3DL2D S

+ p1modGauss-1ZEUS (prel.) 135 pb

HERA II

) (GeV)ππM(K1.7 1.75 1.8 1.85 1.9 1.95 2 2.05 2.1

Co

mb

inat

ion

s / 1

0 M

eV

0

100

200

300

400

500

600

700

800

900

1000

D+ (prel.)135 pb−1

HERA-IIlifetime selectionLXY /σLXY

> 3

Measured in a given η(D), pT(D) range,extrapolated to inclusive F cc

2using FFNS NLO (HVQDIS) =⇒

)2 (GeV2Q1 10 210 310 410

cc 2,F

FN

F-210

-110

1

10

210

310

410

510

ZEUS

)9X=0.00008 (x4

)8X=0.00018 (x4

)7X=0.00035 (x4

)6X=0.00060 (x4

)5X=0.00100 (x4

)4X=0.00150 (x4

)3X=0.00300 (x4

)2X=0.00600 (x4

)1X=0.01300 (x4

)0X=0.03000 (x4

)10X=0.00003(x4

-1ZEUS (prel.) D* 162 pb

ZEUS NLO

ZEUS 98-00 D*-1 135 pb+ZEUS (prel.) D

ZEUS


Charm Fragmentation

- heavy quark production is an independent tool to access g(x)

- heavy quarks are tagged from heavy mesons, a precise comparison with theoryneeds knowledge of nonperturbative fragmentation

0.0

0.1

0.2

0.3

0.4

0.5

0.6

ZE

US

DIS pγ

ZE

US

H1

DIS - e+ e

)0 D→f (c

)+ D→f (c

)+ D*→f (c

)+s D→f (c

)+cΛ →f (c

(b)

⇑new fragmentation fractions in DIS

ZEUS

0

1

2

0.2 0.4 0.6 0.8 1z

1/σd

σ/dz ZEUS(prel.)120 pb-1

NLO QCD ⊗HAD(Peterson ε=0.0721)NLO QCD ⊗HAD(Peterson ε=0.01)NLO QCD ⊗HAD(Peterson ε=0.2)

Fit: ε=0.0721+0.0139 -0.0123

⇑ D∗ fragmentation functionZ = (E + P||)D/(E + P )jet, PhP, Ej

T > 11GeV

best fit to Peterson ε within NLO theory(FMNR): ε = 0.07


Beauty production

- DIS: F bb2 (prel.) from µ+jet (prelT ) =⇒

39 pb−1 03-04 data,room for improvement

- Photoproduction: measurementsfrom µ+jets, µµ, D∗µtendency to be above theory at low pbT? ⇓

HERA

10-1

1

10

10 2

10 3

0 5 10 15 20 25 30

H1 99-00 b jetH1 99-00 b→µ jetZEUS 96-00 b→µ jetZEUS (prel) 04 b→µ jetZEUS 96-97 b→eH1 97-00 b→D*µZEUS 96-00 b→D*µZEUS (prel) 96-00 bb→µµ

NLO QCD (FMNR)kt fact. (LZ J2003 set 1)

<pT b> (GeV)

dσ/

dp

T b

(p

b/G

eV)

dσ/dpT(ep→ebX)dσ/dpb

Q2<1GeV2, 0.2<y<0.8, |ηb|< 2

10-3

10-2

10-1

1

10

10 2

10 102

103

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

x=0.0002i=5

x=0.0005i=4

x=0.002i=3

x=0.005i=2

x=0.013i=1

x=0.032i=0

Q2 /GeV2

F 2bb_ × 8

i

H1 DataZEUS (prel.) 39 pb-1

MRST04MRST NNLOCTEQ6HQHVQDIS + CTEQ5F4


Scaled charged track momentum distributionsNew prel. results based on full HERA luminosity (475 pb−1)

Extend previous data toQ2 = 40000GeV2

xp = p(track)/(Q/2)current region of Breit frame

Clear scaling violation observed

Compared to NLO withfrag. functions from e+e−

Agreement not so good

(similarly for MC and MLLA)

ZEUS

0

100

200

300

102

103

104

0< xp < 0.02

ZEUS (prel.) 0.5 fb-1

ZEUS 38 pb-1

1/σ

dσ /

d x p

0

20

40

60

80

100

102

103

104

0.02< xp < 0.05

Kretzer 0.5 < µR < 2AKKKKP

0

10

20

30

40

102

103

104

0.05< xp < 0.1

0

5

10

15

102

103

104

0.1< xp < 0.2

0

1

2

3

4

5

102

103

104

0.2< xp < 0.3

0

1

2

3

102

103

104

0.3< xp < 0.4

0

0.25

0.5

0.75

1

102

103

104

0.4< xp < 0.5

Q2 (GeV2)

0

0.1

0.2

0.3

0.4

0.5

102

103

104

0.5< xp < 0.7

Q2 (GeV2)

0

0.05

0.1

0.15

102

103

104

0.7< xp < 1

Q2 (GeV2)


Inclusive diffraction

Diffraction selected with three methods:small mass of the hadronic system (MX)large rapidity gap (LRG)leading proton (LPS)

Ratio LPS/LRG 2000 (prel.) =⇒

Agreement at ∼ 10%, differences under investigation⇓

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

0

1

10-4

10-3

10-2

ZEUS

FD

(3)

2

(LP

S)/F

D(3

)

2

(LR

G)

ZEUS LPS/LRG 00 (prel.)

β=0.217 β=0.065 β=0.020

Q2

(GeV2)

2.5

3.9

7.1

14

40

β=0.007

β=0.302 β=0.098 β=0.031 β=0.011

β=0.441 β=0.165 β=0.055 β=0.019

β=0.609 β=0.280 β=0.104 β=0.037

β=0.816 β=0.526 β=0.248 β=0.100

xIP

0

1

10-4

10-3

10-2

FD(3)2 from

MX 98-99

MX 99-00(prel.)

LRG 00 (prel.)

=⇒

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

ZEUS

x IPF

2D(3

)

β=0.652ZEUS MX 98-99

β=0.231ZEUS MX 99-00 (prel.)

β=0.070ZEUS LRG 00 (prel.)

β=0.022 β=0.007 β=0.003Q2

(GeV2)

2.7

β=0.735 β=0.308 β=0.100 β=0.032 β=0.010 β=0.004

4

β=0.806 β=0.400 β=0.143 β=0.047 β=0.015 β=0.007

6

β=0.847 β=0.471 β=0.182 β=0.062 β=0.020 β=0.009

8

β=0.907 β=0.609 β=0.280 β=0.104 β=0.034 β=0.015

14

β=0.946 β=0.735 β=0.410 β=0.171 β=0.027

25

β=0.960 β=0.795 β=0.493 β=0.224 β=0.080 β=0.037

35

xIP

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

0

0.05

10-4

10-3

10-2

ZEUS

x IPF

2D(3

)

β=0.969ZEUS MX 98-99

β=0.833ZEUS MX 99-00 (prel.)

β=0.556ZEUS LRG 00 (prel.)

β=0.271 β=0.101 β=0.048Q2

(GeV2)

45

β=0.974 β=0.859 β=0.604 β=0.312 β=0.121 β=0.058

55

β=0.980 β=0.886 β=0.660 β=0.366 β=0.149 β=0.072

70

β=0.984 β=0.909 β=0.714 β=0.427 β=0.184 β=0.091

90

β=0.988 β=0.930 β=0.769 β=0.498 β=0.231

120

β=0.992 β=0.955 β=0.841 β=0.611 β=0.322 β=0.174

190

β=0.996 β=0.973 β=0.899 β=0.726 β=0.444

320

xIP

0

0.05

10-4

10-3

10-2


Hard diffraction in photoproductionDo dPDFs extracted from inclusive DIS describe hard processes in photoprodution ?

HERA-I data

Diffractive D∗ photoproduction

ZEUS

xIP

dσ/d

x IP (

nb)

ZEUS

ep→eD*X'p

79 pb-1

NLO QCD (FMNR)

H1 2006 Fit AH1 2006 Fit AH1 2006 Fit BZEUS LPS+charm Fit

0

20

40

60

80

100

120

140

160

0 0.005 0.01 0.015 0.02 0.025 0.03 0.035

D∗ PhP

pT > 2GeV

|η| < 1.5

Agreement with diff. QCD factorization

Diffractive dijets

(p

b)

ob

sγ

/dx

σd

200

400

600

(p

b)

ob

sγ

/dx

σd

200

400

600 -1ZEUS 77 pb

ZEUS LPS, GRV

H1 2006 A, AFG (x 0.87)

H1 2006 A, GRV (x 0.87)

H1 2006 B, GRV (x 0.87)

(a)

(d

ata/

NL

O)

ob

sγ

/dx

σd

1

2

3

(d

ata/

NL

O)

ob

sγ

/dx

σd

1

2

3 (b)

obsγx

0.4 0.6 0.8 1.0

had

r. c

orr

.

1

2

obsγx

0.4 0.6 0.8 1.0

had

r. c

orr

.

1

2

Dijet PhP

Ej1,2T > 7.5,5.5GeV

|ηj| < 1.5xIP < 0.025

⇐ NLO uncertainty

⇐ with Resolved ×0.36

- data final, theory (KK) being checked- no evidence for factorisation breaking


Exclusive ρ0 production in DISZEUS

Q2 (GeV2)

σγ*p

→ ρ

p (

nb

)

ZEUS (prel.) (120 pb-1) ZEUS 1995 ZEUS 1994

10-2

10-1

1

10

10 2

10 3

10 4

10-2

10-1

1 10 102

ZEUS

Q2 (GeV2)R

=σL/σ

T

ZEUS (PHP 2.2pb-1)ZEUS (BPC 3.8pb-1)

ZEUS (prel.) (120 pb-1)

0

2

4

6

8

10

12

14

0 10 20 30 40 50

ZEUS

ZEUS (prel.) (120 pb-1)

W (GeV)

σγ*p

→ ρ

p (

nb

)

10-1

1

10

10 2

10 3

20 40 60 80 100 120 140 160 180 200

ZEUS

Q2 (GeV2)

δ

ZEUS (prel.) (120 pb-1)ZEUS 94ZEUS 95

0

0.2

0.4

0.6

0.8

1

1.2

0 5 10 15 20 25 30 35 40

Full HERA-I data (prel.)

Precise data up to large Q2

R = σL/σT increase with Q2

σ(γ∗p) ∝W δ

δ strongly increasing with Q2


DIS at high yExtending the DIS analysis to high y (low x, low Ee)Preparation for FL analysis with low energy dataSpecial high-y trigger in 2006: 29 pb−1 e+p data (prel.)

ZEUS

σ~

y

0

1

22= 27 GeV2Q

0

1

22= 70 GeV2Q

0

1

22= 200 GeV2Q

0 0.5 10

1

2 2= 650 GeV2Q

2= 35 GeV2Q

2= 90 GeV2Q

2= 250 GeV2Q

0 0.5 1

2= 800 GeV2Q

2= 45 GeV2Q

2= 120 GeV2Q

2= 350 GeV2Q

0 0.5 1

2= 1200 GeV2Q

2= 60 GeV2Q

2= 150 GeV2Q

2= 450 GeV2Q

ZEUS (prel.)

)-106e+p (29pb

CTEQ5d

ZEUS-Jets

ZEUS

CT

EQ

5Dσ

/ m

eas

σ~

~

y

0.5

1

1.5 2= 27 GeV2Q

0.5

1

1.5 2= 70 GeV2Q

0.5

1

1.52= 200 GeV2Q

0 0.2 0.4 0.6 0.8 10.5

1

1.5

2= 650 GeV2Q

2= 35 GeV2Q

2= 90 GeV2Q

2= 250 GeV2Q

0 0.2 0.4 0.6 0.8 1

2= 800 GeV2Q

2= 45 GeV2Q

2= 120 GeV2Q

2= 350 GeV2Q

0 0.2 0.4 0.6 0.8 1

2= 1200 GeV2Q

2= 60 GeV2Q

2= 150 GeV2Q

2= 450 GeV2Q

ZEUS 96/07

ZEUS (prel.)

)-106e+p (29pb

Improves over HERA-I at high-yfor Q2 <∼ 100GeV2


First look at Low Energy data

First data collected at reduced proton energy Ep = 460GeV, Ee = 27.6GeV

σ = F2(x,Q2) − y2

Y+FL(x,Q

2)

y2/Y+

ZEUS Control Plots= 225 GeVsFirst Data from HERA Runs at

(GeV)eE0 5 10 15 20 25 30 35 40

Eve

nts

0

200

400

600

800

1000

(GeV)eE0 5 10 15 20 25 30 35 40

Eve

nts

0

200

400

600

800

1000

)2(GeVel2Q

1 10 210 310 410

Eve

nts

0

500

1000

1500

2000

2500

3000

)2(GeVel2Q

1 10 210 310 410

Eve

nts

0

500

1000

1500

2000

2500

3000

elx-410 -310 -210 -110 1

Eve

nts

0

200

400

600

800

1000

1200

elx-410 -310 -210 -110 1

Eve

nts

0

200

400

600

800

1000

1200

ely

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Eve

nts

0

100

200

300

400

500

600

700

ely

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Eve

nts

0

100

200

300

400

500

600

700 -1ZEUS, L = 0.96 pb

Data

pγMC DIS +

pγMC

Everything looks as expected

Looking forward for a promising FL measurement


Conclusions

ZEUS collected 0.50 fb−1, analysis of full luminosity just started

Results on High-Q2 DIS from full e−p HERA-II data

will be input to next generation of PDF and EW fits

No deviation from SM seen in NC DIS, multileptons, isolated leptons

New jet data, precision tests of QCD, sensitivity on g(x), αs

HERA-II measurements of heavy flavours production are coming,

new constraints to g(x)?

Finalising HERA-I measurements of diffraction

Low-energy run for the measurement of FL going well


Documents

Massimo Corradi - file- Azimuthal Asymmetries in NC DIS - Search for Stop in Rp-violating SUSY - Open Beauty in the D - Final State - Rapidity Gaps Between Jets in PhP - K0 S and Production