1. WW Scattering studies for the Future Linear Collider Andres F. Osorio Postgraduate student High Energy Physics Group

2. Contents Motivation Work done/ preliminary results Final remarks

3. Motivation To study WW scattering in the frame of the Electroweak Chiral Langrangian at e + e - colliders “WW scattering at LHC”, J. Butterworth, B. Cox, J. Forshaw “Strong Electroweak Symmetry Breaking Signals in WW scattering at TESLA”, R. Chierici, S. Rosati, M. Kobel W L W L  W L W L Sensitive to the physics of Electroweak Symmetry breaking Look for resonances (scalar, vector, …) Compare with LHC

4. First steps Generating a SM Higgs of mass M h 0 = 300 GeV/c 2 C.M.E. of 800 GeV. Generating my events with Pythia 6.2 Look for the 4 quarks final states using a jet finder algorithm No detector simulation for the moment

5. Quick review SM Higgs production at e + e - collider: * Higgs-strahlung * WW fusion SM Higgs decays modes

6. Analysis Using the K T algorithm (C++ implementation) -> E recombination scheme. -> Force to have 4 jets. It is clear that this should work but I’m having problems when I form pairs of jets and reconstruct the signal. ->This isn’t working, so I had to perform a subjet analysis (using ycut set to 0.0005).

7. Signal L = 500 fb -1 Selection: Take all possible pairs of combinations of jets. Using the criteria |M ij -M W |*|M kl -M W | take the minimum.

8. Background L = 500 fb -1

9. Final remarks It’s not yet well understood why the problem in having only 4 jets: - Is it a problem with the generated events? - Is it a “bug” in the K++? Lots of things to do: - Refine the selection method and apply cuts - Work fully on the background signals (QCD?) - Study the angular distribution Cos ( *)