4-f Contact Interactions

Experimental results from HERA, LEP and Tevatron.Corinne Goy LAPP – Annecy-Le-Vieux

f f ´

f f ´

Physics Beyond The Standard Model. Corinne.Goy@lapp.in2p3.fr

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 2

Formalism (Eichten et al.)

ef : Energy scale of the new physics

• Flavours and helicity : numerous combinations

• The various colliders are sensitive to different couplings

• Lepton & Quark universality, SU(2) U(1) symmetry

• : Constructive or destructive interference with SM

• = 0,± 1 : Relative sign of the different helicity contributions

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 3

Some Contact Interactions Models

Parity Violating Models Parity Conserving Models

LL RR LR RL VV AA V0(X3) A0 (X4)

LL 1 0 0 0 1 1 1 0

RR 0 1 0 0 1 1 1 0

LR 0 0 1 0 1 -1 0 1

RL 0 0 0 1 1 -1 0 1

Parity Violating Models

constrained by low energy experiment such as Atomic Parity Violation

e-u, e-d: LL,RR,LR,RL > ~10 TeV Contact Interactions with

Scalar couplings: [eiei][fjfj]

Tensor couplings: [eiei][fjfj]

well constrained by measurements from pion decay , anomalous magnetic moment (e,)

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 4

HERA

• Sensitivity to eeqq :

– valence quark

• Observables :

– Neutral Current : d/dQ2

• Luminosity :

– e-p : ~16 pb-1 @ s = 319 GeV

– e+p : ~ 101 pb-1 @ s = 301, 319 GeV

• Experimental uncertainty

– Energy scale , P-id : 3 %

– Lum uncertainty : 1.5 to 1.8 %

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 5

HERA : H1 final distribution

SM uncertainty ~ 1% :

s = 0.1185 +/- 0.003

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 6

HERA

Final H1 limits

e-u

o nl y

-

1.6 – 5.5 TeV

+

2.8 – 5.3 TeV

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 7

EW Charge Distribution

)6

1)(6

1( 22

22

22 QR

QR

QQqe

SM

dd

dd

<Re> = 0 <Re> = <Rq>

<R> (10-18 m) 1. 0.7

Final H1 limits :

electron point like

prel.

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 8

Tevatron

• Unique sensitivity to :

– 4q and qq

– mainly valence quarks for initial states

• Observables :

– d/dM jet jet

– Drell-Yan production : d/dM ll spectrum

• Run I : ~110 pb –1/exp @ s = 1.8 TeV

• Run II : ~ 130 –150 pb-1/exp @ s = 1.96 TeV …

• Exp syst : jet energy scale, luminosity

• Theoretical uncertainty due to PDF and renormalisation scale

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 9

Tevatron

(Update D0/ CDF speakers @ this conference for recent results using Run II data)

+LL- 4q > 2.7 Tev

@ D0 Run I

-LL- 4q > 2.4 TeV

+q

(-q) > 2.9 (3.5) TeV @ CDF Run I

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 10

LEP II

• Unique sensitivity to

– 4 Leptons

– Heavy Quarks

– Neutrino

• Observables : 2-fermions cross-sections : (e+e- ff ), d/dcos

Asymmetries : AFB

Heavy Flavours : Rb, Rc, AFBb, AFB

c

s : from 130 to 208 GeV cumulating 700 pb-1 / exp 2.8 fb-1 @ LEP

– with S = 189 GeV L = 680 pb-1 @ LEP

– with S = 208 GeV L = 650 pb-1 @ LEP qq Rb ee All

FB

189GeV – LEP 1 % 4% 2% 2.5% 1% 0.021

Theoritical error reduced to 1/3 of the combined LEP experimental error (LEP2 MC Workshop)

0.26% 0.4% 0.4% 2% 0.004

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 11

2-Fermions Cross-Sections and Asymmetries

qq = +1.7

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 12

Heavy Quarks

SM :

-2.08

+0.30

SM :

-1.56

-0.24

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 13

Fully Leptonic

> 9 TeV

-

TeV e-u e-dLL 6.7 10.2 10.6 6.0

RR 5.7 8.3 2.2 4.3

VV 9.6 14.3 11.4 7.0

AA 8.0 11.5 13.3 7.7

LR 4.2 2.3 2.7 3.5

RL 3.5 2.8 4.2 2.4

V0 8.7 13.4 12.5 7.1

A0 4.9 2.8 4.2 3.3

Had

ron

ic

Selecting couplings to u/d

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 15

LEP : Neutrinos Contact Interactions

Z return

Single final states

Simulation

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 16

DELPHI : Neutrinos Contact Interactions

Interpretations :

e+e- ee ,

e+e- ,

Coloured regions are not excluded

22GF = 4/2

> 1.3 TeV

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 17

DELPHI: Single Top

) g(s, C and ) f(s, β h wit

β))(3VVVV( β)(1 S 23 β)(3 T 8

ΛC σ

βm22

t

2LR

2RL

2RR

2LL

2RR

2RR4

NS

TeV

1.3 1.1 0.6 1.0 0.5 1.0 1.0

TRR 1 1

SRR 1 1

V 1 1 1 1

aLRZ 1 1 -1

SM 0

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 18

Defined Models

Sensitivity to masses well beyond s

Z’ GKK LQ

f

f

~

f

f

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 19

Z’ : MZ’

GeV LEPCDF I

(Direct)

E6 () 673 595

E6 () 481 590

E6 () 434 620

L-R 804 630

SSM 1787 690

LEP : 2-fermions cross-sections and asymmetries. (LEP1 : Z-Z’ mixing = 0)

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 20

R-Parity Violating Sneutrinos

From e+e- e+e- differential cross-sections

Aleph Preliminary

(final statistics)

4 * Luminosity

~

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 21

Large Scale Gravity : 4 /2 = f /MS4

Prel. LEP : d(e+e- e+e-)/dcos

TeV Ms - Ms +

LEP (Hewett) 1.2 1.

H1 (GRW) 0.780 0.820

Tevatron (Run I) ~ 0.9 -1 TeV

(M. Sanders @ this session)

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 22

Leptoquarks : 4 /2 = g2 /MLQ2

LQ

(RPV q)

H1(final limits)

MLQ GeV/g

LEP

S0L 710 2150

S0R 640 1700

Š0R 330 660

S ½ L 850 590

S ½ R 370 770

Š ½ L 430 -

S1L 490 1190

V0L 730 3030

V0R 580 540

V~0R 990 1610

V1/2L 420 1000

V½R 950 750

V~1/2L 1020 580

V1L 1360 2170

(A.F Zarnecki @ this session)

LE

P L

3

Scalar Leptoquarks with F=2 (S0L)

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 23

Conclusion

• 4-Fermions Interactions well described so far by the Standard Model > 1 to 10 TeV

• Precision measurements (LEP-HERA)

– Z’SM > 1.7 TeV

– Ms > 1 TeV

– MLQ > Several 100 GeV for g = 0.3

• Tevatron : 2fb-1

– e/-q(u,d) : ~ 7 TeV

– Ms ~ 2 TeV

• HERA II :

– Polarisation Program : specific helicity states

• LHC : ……

but let’s hope for direct New Physics discoveries.

July-2003 Corinne.Goy, LAPP Annecy-Le-Vieux. EPS-2003 24

Leptoquark : Couplings e-c / e-b

Rc, AFBc and -had Rb, AFB

b