1. W - TGCs at a γγ – collider at TESLA
K.Mönig, J.Sekaric
DESY-Zeuthen
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

2. Two couplings, κγ in dim-4 and λγ in dim-6 operators
Introduction
Dominating diagram for γγ  W+W-
TGC
Two couplings, κγ in dim-4 and λγ in dim-6 operators
Deviations from SM TGC values  test of EW theory, probe of some possible extensions  new physics beyond the SM q 
Ambiguities :
(cosθ1,2,φ1,2) ↔
(-cosθ1,2,φ1,2+π)
WBACKWARD y 1 x 2 x 1 z 2  z y
WFORWARD q 
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

3. Denner, Dittmaier, Schuster, hep-ph/9503442
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

4. Denner, Dittmaier, Schuster, hep-ph/9503442
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

5. Total Cross-Section - Whizard
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

6. Deviation effects of WLL’s in presence of anomalous coupling
Differential Cross-Section
Deviation effects of WLL’s in presence of anomalous coupling
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

7. Deviation effects of WLL’s in presence of anomalous coupling
Differential Cross-Section
Deviation effects of WLL’s in presence of anomalous coupling
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

8. Analysis
Signal (γγ→WW) sample for JZ=0(±±),2(± ) (WHIZARD – W. Kilian, 100% polarized photon beams, fixed beam energy)
σhad(0)=35pb; σhad(2)=31pb
Response of a detector simulated with SIMDET V4
Ws are reconstructed from hadronic final states
MW=(60-100) GeV; θnenflo>7º; NENFLO>10; NCT>5;
pile-up (no track rejection) 1.8 ev/BX
Estimated errors of measurement of  and  parameters, obtained by binned Likelihood fit
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

9. WFORWARD WFORWARD WBACKWARD
MW1 [GeV]
WFORWARD
WBACKWARD
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

10. ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

11. Monte Carlo Fit
Each event described with 5 kinematical variables (sensitive to TGC) :
- W production angle, cosθ of forward W-boson
- W polar decay angles, cosθ1,2 (sensitive to the different W helicity states) of higher energetic jet
azimuthal decay angles, 1,2 (sensitive to the interference between different W helicity states) of higher energetic jet
Matrix element calculations (WHIZARD-O’Mega)  weights to reweight SM events (Δκγ=0, Δλγ=0) as functions of anomalous TGC by
Weight/event:
R(,) = 1 + A· + B·()2 + C· + D·()2 + E · 
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

12. ND=NSM- data sample (SM), NMC- Monte Carlo sample [NSM·R(,)], L – error on luminosity measurement
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

13. Likelihood (normalized) DETECTOR LEVEL MW1,2=(60 – 100) GeV
2 Parameter Fit Results – JZ=0
JZ=0
3D/5D
(φ=0-2π)
ECM = 400 GeV, L = 110 fb-1 , FBE
Likelihood (normalized)
DETECTOR LEVEL MW1,2=(60 – 100) GeV L 1%
0.1%
accurate
 ·10-4/10-4
26.0/14.4
6.2/5.4
3.8/2.6
 ·10-4/10-4
14.4/3.0
13.7/3.0
 ·10-4 +pileup
15.4
5.4
2.6
 ·10-4 +pileup
3.8
3D  5D decreases the error in  ; in  significantly !
Pile-up distorts the φ-distribution  increase of error
in  for ~20%
 dependences on normalization
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

14. Likelihood (normalized) DETECTOR LEVEL MW1,2=(60 – 100) GeV
2 Parameter Fit Results – JZ=2
JZ=2
3D/5D
(φ=0-2π)
ECM = 400 GeV, L = 110 fb-1 , FBE
Likelihood (normalized)
DETECTOR LEVEL MW1,2=(60 – 100) GeV L 1%
0.1%
accurate
 ·10-4/10-4
29.0/19.9
6.2/6.2
3.9/3.8
 ·10-4/10-4
1.8/1.5
1.6/1.5
 ·10-4 +pileup
23.2
6.3
3.9
 ·10-4 +pileup
2.0
3D  5D no influences in the error estimations
Pile-up distorts the φ-distribution  increase of error
in  for ~25%
 dependences on normalization
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

15. Conclusions
JZ =0,2 are sensitive to the anomalous couplings  to the possible scenarios of EWSB
φ distribution important for JZ=0
Pile­up influences on λγ measurement (~25%)
Promising channel for κγ - λγ measurements
Δκγ, Δλγ ~ 10-4
FUTURE
to include the possible backgrounds, variable beam energy
rejection of bad tracks from pileup
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen

16. ANALYTIC FORMULA γγ  WW
Backup
Dominated WTT fraction
σWHIZARD scaled to the σFORMULA
WHIZARD γγ  WW
ANALYTIC FORMULA γγ  WW
ECFA, Sept. 04, UK
Sekaric Jadranka
DESY-Zeuthen