towards higgs precision measurement at ilc what we have done ? & what we have to do?
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Towards Higgs Precision Towards Higgs Precision Measurement at ILCMeasurement at ILC
What we have done ? & What we have to do?What we have done ? & What we have to do?
JAPAN LC Physics study group Higgs subgroupand
KEK Minamitateya Collaboration
Yoshiaki Yasui(Tokyo Management Collage)
ACFA 7th Nov.9-12 2004 Taipei Taiwan
Why Precision MeasurementWhy Precision Measurement??Why Precision MeasurementWhy 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
SM New Physics!! Higgs coupling may be a probe of BSM
What we can do after Higgs discovery @ LHC?
Higgs Precision Measurement EW SSB, mass generation
MSSM at ILC? MSSM at ILC? MSSM at ILC? MSSM at ILC?
But .....
Decoupling limit MH0 ≈ MH
≈ MA0 >> MZ
hhh = (3gMZ/Cw)cos2sin()
3gMh02/2MW = hhh
SM (MhSM=Mh0)
hhhh = (3g2/Cw
2)cos22 3g2Mh0
2/4MW2
=SMhhhh(Mh
SM=Mh0)
Top Yukawa corrections are small Hollik et.al.
Higgs self coupling = gauge coupling?
We need more idea!!
Non SUSY THD at ILC?Non SUSY THD at ILC?Non SUSY THD at ILC?Non SUSY THD at ILC?● Higgs self coupling as a probe of THD
Kanemura et.al LCWS’04 Paris
Baryogenesis talk by Senaha-san
Extra-dim at ILC?Extra-dim at ILC?Extra-dim at ILC?Extra-dim at ILC?● Radion(graviscalar)-Higgs mixing
Ex:Warped Extra Dim model Randall Sundrum
radion mass mPlanck-warped scale
Dominici et.al. Nucl.Phys. B671 (2003)
=5GeV
zzh
hhh=5GeV
m > 2mh ⇒ hh bbbbmmh, >> 1⇒ gg 0
Towards Towards Higgs Precision MeasurementHiggs Precision Measurement 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.)
feedback
this talk
What we have done?What we have done?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 KoreaLCWS '02 Jeju Korea
LCWS’04 Paris France Quick Simulation (includes bkg.) study!!
dominant for E
CM > 1TeV
1. Parton level Generator (tree level ⇔ GRACE-loop)● LCGrace talk by Yasui, ACFA 6th India 2003
package for LC Higgs physics study: Mh ≤ 140 GeV e+e- 6f
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 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
ννhh 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
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
ννhh Analysis Flowννhh Analysis Flow
dep. of cross-section
νeνehh
Zhh
/SM
L = 1 ab-1
ννbbbb
ννbbh =SM
=
Reconstructed ‘Higgs’ mass
ννbbbb
Likelihood
ννbbh
ννhh
=
=SM
coun
ts
L = 1 ab-1
ννhh selection
(~ OPAL Higgs scheme)(~ OPAL Higgs scheme)
Missing mass [GeV]
‘Zhh’
‘fusion’
ννhh channel
coun
ts
Separate Zhh & fusion
(= 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 distributionsHH 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 sensitivityhhh Measurement sensitivity
Precise study Radiative corrections are also important!! Systematic study of the RC for Higgs physics at LC with GRACE
Radiative correction for Radiative correction for ee++ee--ZHH
GRACE Phys.Lett.B576(2003)152Zhang et al. Phys.Lett.B578(2004)349
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--ννeeνν
ee HHHH
Yasui et.al. ECFA2004 Durham UK
Single Higgs production
● e+e-ZH (full number of graphs = 341)
● e+e-ννH (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-νeνe 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
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)
SummarySummarySummarySummaryWhat we have done?
What we have to do?
Non-b decay of the Higgs increase sensitivity
Mh>140GeV W-par decay of the Higgs
ννhh 8f, 10f New version of Grace system
Radiative corrections (systematic study have been done)
sizable include in the event generator
New Physics study
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