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Higgs in Collins-Soper land Measurements on the Higgs spin and CP Nikhef Atlas Outing 2014 Koen Oussoren

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Content Why spin & CP? Current spin analysis in HWW channel Collins-Soper Frame Variables of interest Reco Higgs Prospects and Challenges Conclusion Koen Oussoren - Atlas Outing 20142

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Why spin and CP? SM is boring Something new would spice up things a bit Different models predict Higgs to have different spin/CP, so not scalar-like Testing our understanding of the physics Spin/CP studies mainly involve shape analysis and are complementary to rate and coupling analysis Koen Oussoren - Atlas Outing 20143

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HWW analysis Higgs decay to WW Dileptonic W decay Events to look for have 2 leptons and quite a bit of missing transverse energy Spin analysis revolved mainly around lepton kinematics Outcome: What we see is pretty much SM-like CP-mixing analysis Mixture between SM-like and pseudo-scalar Higgs Setting limits on mixing angle α BDT analysis My current contribution? General method for finding Fourier components of lepton angles and momenta in a specifically chosen Higgs rest frame Koen Oussoren - Atlas Outing 20144

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Collins-Soper frame First used by Collins-Soper to modify the Drell-Yan model to account for transverse momentum (1977) Particles B and A are gluons (quarks) that fuse into a Higgs. Z-axis is the bisection of Pa and –Pb X-axis is “away”-vector of Pa+Pb and also direction of the Higgs in lab frame Koen Oussoren - Atlas Outing 20145

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Angles Angles θ and ϕ are well defined in this frame Together with the momentum of the leptons all the information on Higgs spin/CP is available Any preference for the angles and the momentum will not be washed out in the CS-frame Interesting for studies on C, P and T violation x z lab z y θ φ Koen Oussoren - Atlas Outing 20146

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What to expect? Δφ ll and Δθ ll Small for spin-0 Higgs, large for spin-2 resonances ΔP ll and SumP ll Sum and difference of momentum magnitude l + and l - Information on the energy of the on and off-shell W Koen Oussoren - Atlas Outing 20147

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Polar Angle theta J p = scalar W decay

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SP and DP J p = scalar W decay

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Koen Oussoren - Atlas Outing J p =

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Strategy Fourier decomposition For ΔP ll and SumP ll this is relatively simple 1D problem and symmetric components only θ and φ are a bit more complicated Work in progress Koen Oussoren - Atlas Outing

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SumP p0: ,sig: 424 SumP p1: ,sig: 1362 SumP p2: ,sig: 368 SumP p3: ,sig: 166 SumP p4: ,sig: 94 SumP p5: ,sig: 61 SumP p6: ,sig: 44 SumP p7: ,sig: 34 SumP p8: ,sig: 27 SumP p9: ,sig: 20 SumP p0: ,sig: 424 SumP p1: ,sig: 1622 SumP p2: ,sig: 433 SumP p3: ,sig: 195 SumP p4: ,sig: 108 SumP p5: ,sig: 70 SumP p6: ,sig: 48 SumP p7: ,sig: 34 SumP p8: ,sig: 26 SumP p9: ,sig: NAH!

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DeltaP p0: ,sig: 424 DeltaP p1: ,sig: 427 DeltaP p2: ,sig: 131 DeltaP p3: ,sig: 119 DeltaP p4: ,sig: 30 DeltaP p5: ,sig: 5 DeltaP p6: ,sig: 0 DeltaP p7: ,sig: 0 DeltaP p8: ,sig: 2 DeltaP p9: ,sig: 1 DeltaP p0: ,sig: 424 DeltaP p1: ,sig: 280 DeltaP p2: ,sig: 32 DeltaP p3: ,sig: 97 DeltaP p4: ,sig: 47 DeltaP p5: ,sig: 9 DeltaP p6: ,sig: 9 DeltaP p7: ,sig: 6 DeltaP p8: ,sig: 1 DeltaP p9: ,sig:

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Reco Higgs Nice! But how about the neutrinos? See Rosemarie’s talk Reco code Reconstruct z-component of di-neutrino system Now able to boost to CS-frame Let’s see what happens with ΔP ll Koen Oussoren - Atlas Outing

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RECO

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Prospects CP-Mixings analysis See how the most significant parameters change with cos(α) Plots below show cos(α) = 0, 0.25, 0.5, 0.75, 1 (SM Higgs) Higher dimensional operators (HDO) See how HDOs influence the parameter values Koen Oussoren - Atlas Outing

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Koen Oussoren - Atlas Outing

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Challenges 18 CUTS

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Conclusion CS-frame Interesting for studies on spin/CP Mixing scalar/pseudo-scalar Future Detector level, cuts and background Parameter scan for mixing and HDOs Koen Oussoren - Atlas Outing

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Back up Koen Oussoren - Atlas Outing

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