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Detector requirements from physics: Higgs

Detector requirements from physics: Higgs. Taikan Suehara Tohoku University. Higgs is a key to TeV world. GeV world where SM is dominant. T eV world where SM is just a perturbation. Fermion mass generation by Yukawa coupling. Higgs issues Naturalness Composite Higgs?

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Detector requirements from physics: Higgs

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  1. Detector requirementsfrom physics: Higgs Taikan Suehara Tohoku University

  2. Higgs is a key to TeV world GeV worldwhere SM isdominant TeV worldwhere SM is justa perturbation Fermionmassgeneration by Yukawa coupling • Higgs issues • Naturalness • Composite Higgs? • Multiple Higgs? Electroweak symmetry breaking “The last fundamentalpiece unproved in Standard Model” BSM(SUSY?) Vacuumcondensation& hhh coupling DarkMatter? Baryo-genesis?

  3. Higgs and BSM theories Typical samples: real deviation of course varied by model parameters ~1% measurement of coupling desired

  4. Higgs physics program: revisited

  5. global fit Snowmass energy frontier report Model independent limited by sZH @ 250 GeV

  6. ll recoil (preliminary) mmh 250 S. Watanuki, TS e h Recoil mass - do not see‘h’ to measure ‘h’ Z* l e Z l mmh 250 eeh 250

  7. ll recoil • Major performance driver • Background: mainly irreducible (2l + X) • Peak width: beam energy spread • Detector-related performance drivers • Momentum resolution – keep current? • ISR tagging – not studied yet • Lower material – brems in eeh- but effect is minor? LoI detector machine w/brems recovery wo/brems recovery

  8. qq recoil • Dedicated to absolute cross section meas. • hope to improve sZH greatly • > 10 x statistics compared to llh • Less model independent –efficiency affected more on Higgs final state • Smaller effects also exist in llh– to be checked • 250 GeV yet to be done, 350/500 done (preliminary) currently not so powerful as llh,but another 3.9% isanyhow important for combination Red: all background Black: qqh + background 3.9% (500 GeV) A. Miyamoto

  9. qq recoil • Strategy • Fixed y (Durham) or R (kT) clustering • Select combination using Z massb-tag / c-tag / jet charge may be usable • Apply several cuts to Z/recoilto separate WW/ZZ • Calculate recoil • Detector requirement • Jet energy resolution (W/Z separation, recoil) • flavor tagging / jet charge (minor)

  10. hbb, cc, gg • main processes to determine Yukawa coupling of Higgs • hbb: great accuracy expected (<< 1%) • maybe limited by b-mass accuracy • systematic errors should be carefully investigated • hcc: not possible at all in LHC • hgg: not possible directly in LHC • But cannot separate from u/d/s quarks in ILC • Performance depends almost exclusively on flavor tagging – good benchmark

  11. flavor tagging vs pixel size T. Mori, TS PRELIMINARY btag ctag c-bkg b-bkg uds-bkg FPCCD uds-bkg nominal fine coarse Actually complicated – depends on vertex finding efficiency,b-c separation efficiency with optimization of algorithm Some difference in c-tag, less apparent in b-tag

  12. Zhh, tth Zhh 500 GeV, mh=120 GeV • huge background of tt • many jets in final states • very high purity b-tagis essential • jet clustering

  13. Higgs coupling determination [JunpingTian] Absolute determination of couplings require knowledge of the total width: An easy example: ~20% precision at 250 GeV Performance driver: 250 GeV: ZH  ZZZ* A more sophisticated example: ~6% precision combining 250 GeV + 500 GeV 500 GeV: nnH nnWW* 2013-07-17, IPMU School "Physics at the ILC" (T. Tanabe)

  14. Total width: hZZ*/WW* HWW* @ 500 GeV HZZ* @ 250 GeV BR@125: 21.5% not done yet? J. Tian BR@125: 2.6% • various decay modes: • 6q • 4q2n • 4q2l • 2q2l2n • 4l(2q,2n) analysis needsa lot of work separation from ZWW need W/Z separationin jet  jet energy resolution

  15. Misc analyses • Angular property of Higgs in search of BSM • HWW* anomalous coupling (Takubo et al.) • Will improve using c-jet charge • Htt with Higgs CP-mixing (Yokoyama et al.) • Require t decay measurements

  16. Physics summary coupling

  17. Detector requirements summary • Vertex finder • b-tag (tth, hhh) • c-tag (h->cc) • Tracking • no critical • Calorimeter/PFA • W/Z separation (qqh, h->ZZ*) esp. ~ 50 GeV • Analysis needed! • Better energy resolution? • resolution in general (tth, hhh) 100 - 200 GeV • Jet clustering more important PFA stillhave some room?

  18. Things to do • Analysis with benchmark detectors • Better performance • better vertex resolution • better energy resolution • Better in cost • worse energy resolution(fewer segment / smaller radius) • smaller magnetic field • Software/analysis • Systematic errorswith control samples • Better algorithms • flavor tag, jet clustering, MVA analysis etc. intensive work byall analysis workersis highly needed!

  19. Total width: hZZ*/WW* ΓH = Γ(HXX) / BR(HXX) Analysis with the same vertexof production and decay250: e+e- Z*  Zh ZZZ* 500: e+e-nnW*W*  nnh nnWW* Partial cross section/ total cross section Use recoil at 250 performance drivers • hZZ* analysis: • 6q • 4q2n • 4q2l • 2q2l2n • 4l(2q,2n) separation from ZWW need W/Z separationin jet  jet energy resolution not analyzed yet!

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