Post on 20-Jan-2016
description
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