Status of LC Physics Study in Japan (II) Higgs/GRACE /Simulation study towards Higgs precision Measurement JAPAN LC Physics study group and KEK Minamitateya Yoshiaki Yasui (Tokyo Management Collage) LC Physics Study Meeting 3/6/2005 KEK Higgs SM New Physics!! Higgs coupling may be a probe of BSM origin of EW SSB, mass generation essential role in particle physics phenomena What we can do after Higgs LHC? Higgs Precision Measurement Direct measurement of self coupling e + e - HH X luminosity upgraded LHC (SLHC) ( e + e - hh X ) ( e + e - hhh X ) Diouadi et.al MSSM at ILC hhh = (3gM Z /C w )cos2 sin( ) hhhh = (3g 2 /C w 2 )cos 2 2 THDM model at ILC Kanemura et.al LCWS04 Paris Loop induced huge correction What we have done? Priority Higgs Physics at TeV LC 1.Higgs self coupling We started (from 2002) 2.Top Yukawa 3.Heavy Higgs, etc. etc.. Assumption No bkg effects 100% signal efficiency by Yasui '02 Jeju Korea LCWS04 Paris France Quick Simulation (includes bkg.) study!! dominant for E CM > 1TeV 1) Parton level Generator (tree level ) LCGrace talk by Yasui, ACFA 6th India 2003 package for LC Higgs physics study : M h 140 GeV e + e - 6 fermion based on the GRACE System Bases Monte Carlo integration Cross section Spring Events generator 2) Hadronizer Pythia (interface from Spring to Pythia6) 3) Simulator (Quick Simulation Full Simulation) 4) Analysis Our Strategy for simulation studies E cm = 1 TeV main mode W-fusion Higgs mass = 120 GeV SM decay Br ISR/BSR included Signal & bkg event generator LCGrace (BASES+SPRING) Signal MC: X + hh / SM from 0.0 to 2.0 with 0.2 step Smearing simulation at parton level Jet energy resolution ~ 30%/E (GeV) (detector R&D target value) Simulation Study 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 M 1 jj ~ M h M 2 jj ~ M h No isolated lepton Signal and Background processes Signal (for SM) Main bkg processes 4b + missing bbbb (~ ZZ, Z *) bbh (~ Zh) By LCGrace Select typical diagrams ( full calculation ) Reconstruction of intermediate resonances 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. hhh measurements Analysis Flow bbbb Likelihood bbh = = SM counts L = 1 ab -1 selection (~ OPAL Higgs scheme) L = 1 ab -1 bbbb bbh = SM = Reconstructed Higgs mass Missing mass [GeV] Zhh fusion hh channel counts Separate & fusion dep. of cross-section e e hh Zhh / SM (= visible mass) fusion-channel hh invariant mass [GeV] counts hh = = SM hh invariant mass [GeV] counts Zhh-channel Zhh = SM =2 SM HH invariant mass distributions M h =120 GeV Measured / SM True / SM 95%CL upper bound 95%CL lower bound 67%CL range I lumi =1 ab -1 Pol beam = M h =120 GeV (SM Higgs Br) Use only hh 4b (Br(hh 4b)~47%) Eff.(4b) 80% By Yamashita et.al. LCWS 2004 hhh Measurement sensitivity A quick simulation study has been performed for E cm =1 TeV For M h =120 GeV: measurement sensitivity (only hh bbbb only) for = SM / SM = (1 ) (95%CL) / SM =0.6 (1 ) (95%CL) / SM =1.4 (1 ) (95%CL) Summary What we have done? What we have to do? Non-b decay of the Higgs increase sensitivity Full 6f calculation M h >140GeV W-par decay of the Higgs 8f, 10f New version of Grace system Radiative corrections are sizable!! systematic study have been done by Grace 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) 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) Single Higgs production e + e - ZH (full number of graphs = 341) e + e - H (1350) Phys.Lett. B559 (2003) 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) Y.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) R.Zhang et.al.PLB(2004)349 e + e - e e HH (19638) New results!! of 2 to 4 Weak corrections are sizable O(5-10)% Recent progress on the loop calculations e+e- e e HH W for Mh=120GeV QED for Mh=120 GeV = (O( ))/ (tree)-1 W G = W - 4 r r=2.267% WW Radiative correction for e + e - e e HH Yasui et.al. ECFA2004 Durham UK ACPP International 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) Towards Higgs Precision Measurement 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.) feedback