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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. - PowerPoint PPT Presentation
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Status of LC Physics StudyStatus of LC Physics Studyin Japan (II)in Japan (II)
Higgs/GRACE /Simulation studyHiggs/GRACE /Simulation study
towards Higgs precision Measurementtowards Higgs precision Measurement
JAPAN LC Physics study groupand
KEK Minamitateya
Yoshiaki Yasui(Tokyo Management Collage)
LC Physics Study Meeting 3/6/2005 KEK
Higgs study @ILCHiggs study @ILC
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 discovery @ 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 = (3gMZ/Cw)cos2sin()
hhhh = (3g2/Cw
2)cos22
THDM model at ILC
Kanemura et.al LCWS’04 Paris
Loop induced huge correction
What we have done?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..
etc..
Assumption No bkg effects 100% signal efficiency
by Yasui et.al.
@LCWS '02 Jeju Korea@LCWS '02 Jeju Korea
LCWS’04 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: Mh ≤ 140 GeV e+e- 6 fermionbased 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 studiesOur Strategy for simulation studies
Ecm = 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 StudySimulation Study
quick analyses
only for hh decaying to 4b
Br(hh4b) ~ 47 %
for 120 GeV SM Higgs
Signal characteristics
Large missing energy, missing PtOnly 4 b jetsM1 jj ~ Mh M2 jj ~ Mh
No isolated lepton
Signal and Background processesSignal and Background processes
Signal (for SM)
Main bkg processes 4b + missing
ννbbbb (~ ννZZ, ννZγ*)
ννbbh (~ ννZh)
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
ννbbbb
Likelihood
ννbbh
=
=SM
coun
ts
L = 1 ab-1
selection
(~ OPAL Higgs scheme)(~ OPAL Higgs scheme)
L = 1 ab-1
ννbbbb
ννbbh =SM
=
Reconstructed ‘Higgs’ mass
Missing mass [GeV]
‘Zhh’
‘fusion’
ννhh channel
coun
ts
Separate & fusiondep. of cross-section
eehh
Zhh
/SM
(= visible mass)
‘fusion-channel’
hh invariant mass [GeV]co
unts
ννhh
=
=SM
hh invariant mass [GeV]
coun
ts
‘Zhh-channel’
Zhh=SM
=2 SM
HH invariant mass distributionsHH invariant mass distributions
Mh=120 GeV
Mea
sure
d /
SM
True /SM
95%CL upper bound
95%CL lower bound
67%CL range
Ilumi=1 ab-1
Pol beam= -80%
@1TeV
Mh=120 GeV(SM Higgs Br)
Use only hh4b(Br(hh4b)~47%)
Eff.(4b) 80%
By Yamashita et.al. LCWS 2004
hhh Measurement sensitivity
A quick simulation study has been performed for Ecm=1 TeV
For Mh=120 GeV: measurement sensitivity (only hhbbbb 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)
SummarySummaryWhat we have done?
What we have to do?
Non-b decay of the Higgs increase sensitivity
Full 6f calculation
Mh>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
GRACEGRACE● GRACE is the Computer code
– automatic calculation of tree level Feynman amplitudes
● e+e- → 6 fermions #Feynman DiagramsO(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-loopGRACE-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 () for 2 to 4 processesGRACE for 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) 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) 163-172 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) 152-164 R.Zhang et.al.PLB(2004)349
● e+e-ee HH (19638) New results!! of 2 to 4
Weak corrections are sizable O(5-10)%
Recent progress on the loop calculationsRecent progress on the loop calculations
e+e-e+e-eeee HH HH
W for Mh=120GeV
QED for Mh=120 GeV
=(O())/(tree)-1
W
G=W
- 4r
r=2.267%
W
Radiative correction for Radiative correction for ee++ee--ee
ee HHHH
Yasui et.al. ECFA2004 Durham UK
ACPPACPPInternational Research GroupInternational Research Group
ACPPACPPInternational Research GroupInternational 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 Towards Higgs Precision MeasurementHiggs 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.)
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