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JAPAN LC Physics study group and KEK Minamitateya Yoshiaki Yasui (Tokyo Management Collage)

JAPAN LC Physics study group and KEK Minamitateya Yoshiaki Yasui (Tokyo Management Collage). LC Physics Study Meeting 3/6/2005 KEK. Status of LC Physics Study in Japan (II) Higgs/GRACE /Simulation study towards Higgs precision Measurement. Higgs study @ILC.

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JAPAN LC Physics study group and KEK Minamitateya Yoshiaki Yasui (Tokyo Management Collage)

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  1. JAPAN LC Physics study group and KEK Minamitateya Yoshiaki Yasui (Tokyo Management Collage) LC Physics Study Meeting 3/6/2005 KEK Status of LC Physics Studyin Japan (II)Higgs/GRACE /Simulation studytowards Higgs precision Measurement

  2. Higgs study @ILC origin of EW SSB, mass generation ⇒essential role in particle physics phenomena What we can do after Higgs discovery @ LHC? ⇒Higgs Precision Measurement SM New Physics!! Higgs coupling may be a probe of BSM

  3. MSSM at ILC • hhh = (3gMZ/Cw)cos2sin() • hhhh = (3g2/Cw2)cos22 • THDM model at ILC Kanemura et.al LCWS’04 Paris Loop induced huge correction Direct measurement of self coupling e+e- →HH X luminosity upgraded LHC (SLHC) (e+e- →hh X) »(e+e- → hhh X)Diouadi et.al

  4. etc.. etc.. What we have done? • Priority ⇒HiggsPhysics at TeV LC • Higgs self coupling⇒We started (from 2002) • Top Yukawa • Heavy Higgs, etc.

  5. @LCWS '02 Jeju Korea Assumption No bkg effects 100% signal efficiency by Yasui et.al. dominant for ECM > 1TeV LCWS’04 Paris France Quick Simulation (includes bkg.) study!!

  6. Our Strategy for simulation studies • Parton level Generator (tree level) • LCGrace talk by Yasui, ACFA 6th India 2003package for LC Higgs physicsstudy: Mh ≤ 140 GeV e+e-ZHH,nnHH  6 fermionbased on the GRACE System • Bases⇒ Monte Carlo integration ⇒ Cross section • Spring⇒ Events generator • Hadronizer • Pythia(interface from Spring to Pythia6) • Simulator (Quick Simulation → Full Simulation) • Analysis

  7. Simulation Study Ecm = 1 TeVmain mode  W-fusion Higgs mass = 120 GeV SM decay Br ISR/BSR included Signal & bkg event generatorLCGrace (BASES+SPRING) Signal MC: X + hh/SM from 0.0 to 2.0 with 0.2 step Smearing simulation at parton levelJet energy resolution ~ 30%/√E (GeV) (detector R&D target value) nnHH quick analyses only for hh decaying to 4b Br(hh4b) ~ 47 % for 120 GeV SM Higgs Signal characteristics Large missing energy, missing Pt Only 4 b jets M1 jj ~ Mh M2 jj ~ Mh No isolated lepton

  8. ννbbbb(~ ννZZ, ννZγ*) ννbbh (~ ννZh) Signal and Background processes By LCGrace Main bkg processes 4b + missing Signal (for SM) Select typical diagrams ( full calculation )  Reconstruction of intermediate resonances

  9. 1. Likelihood selection bkg further reduction 2. Separate Zhh & fusion differentdependence (positive/negative interferences) 3. Combine with Zhh analyses for s-channel process 4. Check hh invariant mass 5. hhhmeasurements nnHHAnalysis Flow

  10. ννbbbb = nnHH selection ννbbh =SM L = 1 ab-1 ννbbbb = nnHH counts =SM ννbbh Likelihood Reconstructed ‘Higgs’ mass L = 1 ab-1 (~ OPAL Higgs scheme)

  11. ννhh channel ‘fusion’ counts ‘Zhh’ dep. of cross-section Zhh Missing mass [GeV] eehh /SM Separate ZHH & fusion

  12. ‘Zhh-channel’ ‘fusion-channel’ =2 SM = counts counts Zhh ννhh =SM =SM hh invariant mass [GeV] hh invariant mass [GeV] (= visible mass) HH invariant mass distributions

  13. @1TeV Ilumi=1 ab-1 Pol beam= -80% 95%CL upper bound Measured /SM Mh=120 GeV (SM Higgs Br) Mh=120 GeV Use only hh4b 67%CL range (Br(hh4b)~47%) Eff.(4b) 80% 95%CL lower bound True/SM hhhMeasurement sensitivity By Yamashita et.al. LCWS 2004

  14. Summary What we have done? A quick simulation study has been performed for Ecm=1 TeV For Mh=120 GeV:measurement sensitivity (only hhbbbb only) for =SM/SM=1.0 +0.13 -0.11 (1) 0.78 - 1.32 (95%CL) /SM=0.6 0.6 +0.10 -0.07 (1) 0.45 - 0.77 (95%CL) /SM=1.4 1.4 +0.14 -0.18 (1) 1.08 - 1.70 (95%CL) What we have to do? Non-b decay of the Higgs  increase sensitivity Full 6f calculation Mh>140GeV  W-par decay of the HiggsnnHH8f, 10f New version of Grace system Radiative corrections are sizable!! systematic study have been done by Grace

  15. GRACE • GRACE is the Computer code • automatic calculation of tree level Feynman amplitudes • e+e- → 6 fermions #Feynman DiagramsO(10000) • e+e- → Zh → ZW+W- → ffffff (Mh ≧ 140GeV) • e+e- → tt-bar → bbW+W- → bbffff • e+e- → Zhh → ffbbbb (Mh ≦ 140 GeV) • Many packages in the world • AMEGIC++, EFTT6F, LUSIFER, PHEGAS, SIXFAP, WHIZARD,.. • No useful tool in Asia!! LCGrace ≠ Full calculation, HELAS is unsupported now • Tool development is essential for ILC physics • GRACE ver.2→ GRACE ver.3 (upgrade for multi-legs)

  16. GRACE-loop • Code for the full one-loop EW corrections • Two packages in the world • FeynArt/FeynCalc e+e- 4 fermion • GRACE-loop e+e-HH • full O(a) for 2 to 4 processes • GRACE for gg collider is now ready with CAIN (photon structure function) • GRACE/SUSY is under construction • Non linear gauge fixing • upgrade reduce  form(by Vermaseren)

  17. Recent progress on the loop calculations • Single Higgs production • e+e-ZH (full number of graphs = 341) • e+e-H (1350) Phys.Lett. B559 (2003) 252-262 A.Denner et.al. PLB 560(2003)196, NPB 660(2003)289 • e+e-e+e- H (4470) Phys.Lett.B600(2004)65-76 • top Yukawa • e+e-t t H (2327)Phys.Lett. B571 (2003) 163-172Y.You et.al.PLB 571(2003)85 A.Denner et.al. PLB 575(2003)290, NPB 68(2004)85 • Multi Higgs production • e+e-ZHH (5417)Phys.Lett. B576 (2003) 152-164 R.Zhang et.al.PLB(2004)349 • e+e-eeHH (19638)New results!! of 2 to 4 • Weak corrections are sizable O(5-10)%

  18. e+e-ee HH

  19. Yasuiet.al. ECFA2004 Durham UK Radiative correction for e+e-eeHH =(O())/(tree)-1 W WG=W- 4r r=2.267% QED for Mh=120 GeV W for Mh=120GeV

  20. ACPPInternational Research Group • Russia (MSU,RAS,RFBR) • France (LAPTH,LAPP,LPC,LPMT,LPT) • Japan (KEK) • GRACE ⇋ CompHEP • Tree level multi-parton • Loop calculation(GRACE-loop) • MSSM (GRACE/SUSY, micrOMEHAs)

  21. Machine design parameters (CM energy, Luminosity,etc.) Detailed study of SM Higgs (Simulation, RC, etc.) New Physics at ILC (SUSY,THD,LH,Extra-Dim,etc.) Towards Higgs Precision Measurement feedback

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