Higgs Physics at CLIC Frank Simon Max-Planck-Institute for Physics - - PowerPoint PPT Presentation
Higgs Physics at CLIC Frank Simon Max-Planck-Institute for Physics PANIC 2014 Hamburg, August 2014 on behalf of CLICdp Outline CLIC: A future TeV-scale e + e - Collider The Higgs Program at CLIC couplings at 350 GeV, 1.4 TeV
Frank Simon
Max-Planck-Institute for Physics
PANIC 2014
Hamburg, August 2014
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
CLIC, a linear e+e- collider at the energy frontier
room-temperatur cavities, gradients of up to 100 MV/m
construction in stages
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
Year
5 10 15 20
]
Integrated luminosity [fb
1000 2000 3000 Integrated luminosity Total 1% peak
0.5 TeV 1.4 TeV 3 TeV First stage luminosity optimised (scenario A)
based on CLIC technology can only be tuned within a factor of ~ 3: Staged construction of the machine
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physics - with considerations for technical constraints:
Provides:
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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photon-induced processes:
γ/γ∗
q q
γ/γ∗ e+e- pairs drive crossing angle & vertex detector radius γγ → hadrons interactions: 3.2 / bunch crossing @ 3 TeV Combined with bunch structure (0.5 ns between BX): Pile-up of hadronic background: ~ 19 TeV in HCAL / bunch train ➫ Needs to be rejected by reconstruction
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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photon-induced processes:
γ/γ∗
q q
γ/γ∗ e+e- pairs drive crossing angle & vertex detector radius γγ → hadrons interactions: 3.2 / bunch crossing @ 3 TeV Combined with bunch structure (0.5 ns between BX): Pile-up of hadronic background: ~ 19 TeV in HCAL / bunch train ➫ Needs to be rejected by reconstruction A further consequence of radiative losses: The luminosity spectrum - characterized by a main peak and a tail to lower energies
[GeV] s'
1000 2000 3000
dN/dE
0.005 0.01 0.015 0.02
77% > 0.99 √s @ 350 GeV 35% > 0.99 √s @ 3 TeV
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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tracking and highly granular calorimeters with time- stamping capability, all in a large high-field solenoid
and hadron-collider type jet finders: A powerful tool for the rejection of γγ → hadrons background
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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tracking and highly granular calorimeters with time- stamping capability, all in a large high-field solenoid
and hadron-collider type jet finders: A powerful tool for the rejection of γγ → hadrons background
e+e− → t¯ t @ 3 TeV
1.2 TeV of background
Reduction of background from 19 TeV to 100 GeV: Challenging CLIC environment under control!
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
[GeV] s
1000 2000 3000
HX) [fb] →
+
(e σ
10
10 1 10
2
10
e
ν
e
ν H
+
H e H Z
H H Z
H t t
e
ν
e
ν H H
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
[GeV] s
1000 2000 3000
HX) [fb] →
+
(e σ
10
10 1 10
2
10
e
ν
e
ν H
+
H e H Z
H H Z
H t t
e
ν
e
ν H H
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Main production modes - give access to couplings and total width ~ 80k ~ 450k ~ 1 M Higgs bosons per stage (w/o polarization)
(Polarization (80%, 0%) provides a boost of 1.8 for WW fusion )
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
[GeV] s
1000 2000 3000
HX) [fb] →
+
(e σ
10
10 1 10
2
10
e
ν
e
ν H
+
H e H Z
H H Z
H t t
e
ν
e
ν H H
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Rarer Processes - ZZ fusion, direct access to top Yukawa, self-coupling Main production modes - give access to couplings and total width ~ 80k ~ 450k ~ 1 M Higgs bosons per stage (w/o polarization)
(Polarization (80%, 0%) provides a boost of 1.8 for WW fusion )
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
colliders) are:
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σ x BR (for specific Higgs decays) σ (for model-independent recoil mass analysis) Both are sensitive to couplings:
σ × BR(H→ ff) ∝ g2
Hiig2 Hff
Γtot σrecoil ∝ g2
HZZ
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
colliders) are:
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σ x BR (for specific Higgs decays) σ (for model-independent recoil mass analysis) Both are sensitive to couplings:
σ × BR(H→ ff) ∝ g2
Hiig2 Hff
Γtot σrecoil ∝ g2
HZZ
A crucial ingredient: The total width - best results when combining ZH and VBF
σ(Hνeνe) × BR(H → WW∗) ∝ g4
HWW
Γtot σ(e+e− → ZH) × BR(H → b¯ b) σ(e+e− → Hνeνe) × BR(H → b¯ b) ∝ g2
HZZ
g2
HWW
gHWW pinned down with model- independent gHZZ and high-BR H->bb decay
➫ Accessible at 350 GeV (134 fb for ZH, 52 fb for Hνν)
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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event reconstruction including PFA
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
[GeV]
recoil
M
100 150 200
Events
50 100 150 200 250
Input total Fitted total Fitted signal Fitted background
model-independent measurement of HZZ coupling
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m2
rec = s + m2 Z − 2EZ
√s
Z -> µµ
(350 GeV, 500 fb-1)
Absolute measurement of HZ cross section: ~ 4.2% (stat) for leptonic Z decays at 350 GeV
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
[GeV]
recoil
M
100 150 200
Events
50 100 150 200 250
Input total Fitted total Fitted signal Fitted background
model-independent measurement of HZZ coupling
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m2
rec = s + m2 Z − 2EZ
√s
Z -> µµ
(350 GeV, 500 fb-1)
Absolute measurement of HZ cross section: ~ 4.2% (stat) for leptonic Z decays at 350 GeV Substantial improvement when using hadronic Z decays
event identification may depend on H decay mode
Including hadronic Z decays: Δσ/σ(HZ) = 1.65% (stat)
/GeV
m
70 80 90 100 110 120 130
/GeV
rec
m
80 100 120 140 160 180 200
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
based on 2-jet events in HZ, with Z->qq.
limited by physics background fluctuations: Δσ x BRinv = 0.57%
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
based on 2-jet events in HZ, with Z->qq.
limited by physics background fluctuations: Δσ x BRinv = 0.57%
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TMVA classifier BDT
0.2 0.4
Entries
10 1 10
2
10
signal τ τ qq qqqq
signal selection in hadronic τ decays precision of σ(HZ) x BR(H-> ττ): 5.7% (preliminary)
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
based on 2-jet events in HZ, with Z->qq.
limited by physics background fluctuations: Δσ x BRinv = 0.57%
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estimated precision 1%, 5%, 6%
conservative estimates used in global fits at present, full studies nearing completion
TMVA classifier BDT
0.2 0.4
Entries
10 1 10
2
10
signal τ τ qq qqqq
signal selection in hadronic τ decays precision of σ(HZ) x BR(H-> ττ): 5.7% (preliminary)
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
capability and high statistics
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~ 430k (750k with e- polarisation) H at 1.4 TeV with 1.5 ab-1 ~ 930k (1.7M with e- polarisation) H at 3 TeV with 2 ab-1
Di-jet invariant mass [GeV]
50 100 150 200
Events / 2GeV
4
10
5
10
6
10
q q
+
e q q
e
ν e q q ν ν q q c c → h b b → h
b-tag efficiency
0.4 0.5 0.6 0.7 0.8 0.9 1
mis-tag eff.
10
10
10 1
c - with overlay c - w/o overlay light - with overlay light - w/o overlay
c-tag efficiency
0.2 0.4 0.6 0.8 1
mis-tag eff.
10
10 1
b - with overlay b - w/o overlay light - with overlay light - w/o overlay
√s = 3 TeV √s = 3 TeV √s = 3 TeV
Results:
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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σ(Hνν) x BR(H->µ+µ-) with 16% precision at 3 TeV (at 1.4 TeV: 38%) BR: 2.1 x 10-4
Di-muon invariant mass [GeV]
105 110 115 120 125 130 135
Events / 0.5 GeV
1 10
2
10
3
10
4
10
No BDT cut
+
µ → h ν ν
+
µ
+
e
+
µ
Di-muon invariant mass [GeV]
105 110 115 120 125 130 135
Events / 0.5 GeV
10 20 30 40 50
With BDT cut
+
µ → h ν ν
+
µ
+
e
+
µ
→
σ(Hνν) x BR(H->γγ) with 15% precision at 1.4 TeV BR: 2.3 x 10-3
σ(Hνν) x BR(H->Zγ) with 42% precision at 1.4 TeV (Z -> qq, e+e-, µ+µ-) BR: 1.6 x 10-3
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
hadronically or one top decaying hadronically, one into blν
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Multivariate signal selection in both channels - combined uncertainty on σ(ttH) x BR(H-> bb): 8.1%
)
2
Higgs candidate mass (GeV/c 20 40 60 80 100 120 140 160 180 200 0.02 0.04 0.06 0.08 0.1 0.12
b b → H, fully hadronic, H t t H t Other t b b t t Z t t t t
Signal likelihood
0.2 0.4 0.6 0.8 1
Events
200 400 600 800 1000 1200
signal MC background MC (reconstructed)
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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At CLIC: Measurement in WW fusion - increasing cross-section at high energies 0.16 fb at 1.4 TeV, 0.63 fb at 3 TeV (increases by 1.8 for 80% e- polarization)
νν
λ λ
–
λ λ
3.0 TeV 1.4 TeV
ν ΗΗν ν ΗΗν ΗΗΗ ΗΗΗ
self-coupling (with a “dilution” by other processes) ΔλHHH ~ 32% (stat) with 1.5 ab-1 at 1.4 TeV ΔλHHH ~ 16% (stat) with 2 ab-1 at 3 TeV ΔλHHH ~ 24% (stat) with 1.5 ab-1 at 1.4 TeV ΔλHHH ~ 12% (stat) with 2 ab-1 at 3 TeV unpolarized 80% e- pol. ~11% accuracy of self-coupling with the full (polarized) CLIC program
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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coupling parameters - A global analysis of all results is required to assess the impact of the CLIC program on the understanding of the Higgs sector
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
determined by a global fit:
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i
i
HZZ,
b = g2 HZZg2 Hbb
νe,H→b¯ b = g2 HWWg2 Hbb
... ΔFi: uncertainty of measurement (σ or σxBR)
Model-independent fit - total width as a free parameter Model-dependent fit - LHC-like constraints
Assumptions: No BSM decays, the total width can be described by a few parameters which parametrize deviations
κ2
i =
Γi Γi|SM
i
i BRi,
In the fit: replace gHii with κHii, ΓH with ΓH,md Two fits:
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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work in progress - current status
Statistical precision Channel Measurement Observable 350 GeV 500 fb−1 ZH Recoil mass distribution mH 120 MeV ZH σ(HZ)×BR(H → invisible) Γinv 0.6% ZH H → bb mass distribution mH tbd ZH σ(HZ)×BR(Z → `+`−) g2
HZZ
4.2% ZH σ(HZ)×BR(Z → qq) g2
HZZ
1.8% ZH σ(HZ)×BR(H → bb) g2
HZZg2 Hbb/ΓH
1%† ZH σ(HZ)×BR(H → cc) g2
HZZg2 Hcc/ΓH
5%† ZH σ(HZ)×BR(H → gg) 6%† ZH σ(HZ)×BR(H → τ+τ−) g2
HZZg2 Hττ/ΓH
5.7% ZH σ(HZ)×BR(H → WW∗) g2
HZZg2 HWW/ΓH
2%† ZH σ(HZ)×BR(H → ZZ∗) g2
HZZg2 HZZ/ΓH
tbd Hνeνe σ(Hνeνe)×BR(H → bb) g2
HWWg2 Hbb/ΓH
3%†
Statistical precision Channel Measurement Observable 1.4 TeV 3.0 TeV 1.5 ab−1 2.0 ab−1 Hνeνe H → bb mass distribution mH 40 MeV∗ 33 MeV∗ Hνeνe σ(Hνeνe)×BR(H → bb) g2
HWWg2 Hbb/ΓH
0.3% 0.2% Hνeνe σ(Hνeνe)×BR(H → cc) g2
HWWg2 Hcc/ΓH
2.9% 2.7% Hνeνe σ(Hνeνe)×BR(H → gg) 1.8% 1.8% Hνeνe σ(Hνeνe)×BR(H → τ+τ−) g2
HWWg2 Hττ/ΓH
3.7%∗ tbd Hνeνe σ(Hνeνe)×BR(H → µ+µ−) g2
HWWg2 Hµµ/ΓH
38% 16% Hνeνe σ(Hνeνe)×BR(H → γγ) 15% tbd Hνeνe σ(Hνeνe)×BR(H → Zγ) 42% tbd Hνeνe σ(Hνeνe)×BR(H → WW∗) g4
HWW/ΓH
1.1%∗ 0.8%∗ Hνeνe σ(Hνeνe)×BR(H → ZZ∗) g2
HWWg2 HZZ/ΓH
3%† 2%† He+e− σ(He+e−)×BR(H → bb) g2
HZZg2 Hbb/ΓH
1%† 0.7%† ttH σ(ttH)×BR(H → bb) g2
Httg2 Hbb/ΓH
8% − HHνeνe σ(HHνeνe) gHHWW 7%∗ 3%∗ HHνeνe σ(HHνeνe) λ 32% 16% HHνeνe with −80% e− polarization λ 24% 12%
all results show expected statistical uncertainties assuming SM values and unpolarised beams
missing results are labelled “tbd” estimates from preliminary studies “†”
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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correlations of measurements not included in fit, input measurements include preliminary estimates
coupling relative to SM
0.95 1 1.05
0.5% ± 2.5% ±
H
Γ µ c τ b t W Z g γ CLIC preliminary
model dependent 350 GeV + 1.4 TeV + 3 TeV
coupling relative to SM
0.9 1 1.1
1% ± 5% ±
H
Γ µ c τ b t W Z g γ CLIC preliminary
model independent 350 GeV + 1.4 TeV + 3 TeV
work in progress - current status
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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➫ model-independent 1% - level determination of most couplings in full program (all limited by the model-independent measurement of the ZH coupling) ➫ 1% to few ‰ with LHC-like model-dependence
correlations of measurements not included in fit, input measurements include preliminary estimates
coupling relative to SM
0.95 1 1.05
0.5% ± 2.5% ±
H
Γ µ c τ b t W Z g γ CLIC preliminary
model dependent 350 GeV + 1.4 TeV + 3 TeV
coupling relative to SM
0.9 1 1.1
1% ± 5% ±
H
Γ µ c τ b t W Z g γ CLIC preliminary
model independent 350 GeV + 1.4 TeV + 3 TeV
work in progress - current status
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
mature option for multi-TeV e+e- collisions
couplings and of invisible decays
determine the expected precision of all relevant couplings and of the total width
per mille with LHC-like constraints
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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2012$16&Development&Phase&
Develop'a'Project'Plan'for'a' staged'implementa5on'in' agreement'with'LHC'findings;' further'technical'developments' with'industry,'performance' studies'for'accelerator'parts'and' systems,'as'well'as'for'detectors.'' '
&2016$17&Decisions&
On'the'basis'of'LHC'data' and'Project'Plans'(for' CLIC'and'other'poten5al' projects),'take'decisions' about'next'project(s)'at' the'Energy'Fron5er.'
2017$22&Prepara8on&Phase&
Finalise'implementa5on'parameters,' Drive'Beam'Facility'and'other'system' verifica5ons,'site'authorisa5on'and' prepara5on'for'industrial' procurement.''' Prepare'detailed'Technical'Proposals' for'the'detectorLsystems.'''
2022$23&Construc8on&Start&
Ready'for'full'construc5on' 'and'main'tunnel'excava5on.''
2023$2030&Construc8on& Phase&&
Stage'1'construc5on'of'a'' 500'GeV'CLIC,'in'parallel'with' detector'construc5on.' Prepara5on'for'implementa5on'
&&2030&Commissioning&&
From'2030,'becoming'ready' for'dataLtaking'as'the'LHC' programme'reaches' comple5on.''
DL CR2 CR1 TA DL delay loop CR combiner ring TA turnaround TBA two-beam acceleration dump drive beam accelerator 0.48 GeV, 4.2 A e– injector 0.25 GeV, 1.2 A TBA 6.5 GeV, 1.2 A 0.25 GeV, 101 A 0.48 GeV, 101 A DRIVE&BEAM&& LINAC&
CLEX&
CLIC&Experimental&Area&
DELAY&& LOOP&
COMBINER& RING&
CTF3&–&Layout&
10&m&
4&A&–&1.2&ms& 150&MeV& 28&A&–&140&ns& 150&MeV&
TwoLBeam&Test&Stand&(TBTS)& Test&Beam&Line&(TBL)&
TA radius = 305 m BC2 delay loop 2.5 km decelerator, 5 sectors of 878 m 819 klystrons 17.4 MW, 60 µs CR2 CR1 circumferences delay loop 73 m CR1 293 m CR2 439 m BDS 1.9km IP TA r=305 m BC2 245 m BDS 1.9km 13 km CR combiner ring TA turnaround DR damping ring PDR predamping ring BC bunch compressor BDS beam delivery system IP interaction point dump BC1 245 m drive beam accelerator 2.75 GeV, 1.0 GHz time delay line e+ injector, 2.86 GeV e+ PDR 389 m e+ DR 427 m booster linac, 2.86 to 9 GeV e+ main linac e– injector, 2.86 GeV e– PDR 389 m e– DR 427 m e– main linac, 12 GHz, 80 MV/m, 4.4 km (c)FT Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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6.5 m ultra low−mass vertex detector with 20 m pixels µ complex forward region with final beam focusing return yoke with instrumentation for muon ID 4 T and 5 T strong solenoids main trackers: TPC+silicon (CLIC_ILD) all−silicon (CLIC_SiD) λ Ι
fine grained (PFA) calorimetry, 1 + 7.5
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
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Fe Yoke
Fe Yoke
CLIC_ILD CLIC_SiD
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
CLIC_ILD and CLIC_SiD detector concepts
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350 GeV 1.4 TeV 3 TeV σ(e+e- → ZH) 134 fb 9 fb 2 fb σ(e+e- → Hveve) 52 fb 279 fb 479 fb σ(e+e- → He+e-) 7 fb 28 fb 49 fb
Cross sections including ISR and luminosity spectrum:
Frank Simon (fsimon@mpp.mpg.de) Higgs Physics at CLIC PANIC2014, Hamburg, August 2014
26 Parameter Measurement precision 350 GeV + 1.4 TeV +3.0 TeV 500 fb−1 +1.5 ab−1 +2.0 ab−1 ΓH,model [%] 1.6 0.29 0.22 κHZZ [%] 0.43 0.31 0.23 κHWW [%] 1.5 0.15 0.11 κHbb [%] 1.7 0.33 0.21 κHtt [%] 3.1 1.0 0.74 κHττ [%] 3.4 1.3 < 1.3 κHgg [%] 3.6 0.76 0.56 κHγγ [%] − 5.6 < 5.6 Parameter Measurement precision 350 GeV + 1.4 TeV +3.0 TeV 500 fb−1 +1.5 ab−1 +2.0 ab−1 mH 120 MeV 30 MeV 20 MeV λ − 24% 11% ΓH [%] 5.0 3.6 3.4 gHZZ [%] 0.8 0.8 0.8 gHWW [%] 1.8 0.9 0.9 gHbb [%] 2.0 1.0 0.9 gHcc [%] 3.2 1.4 1.1 gHtt [%] − 4.1 4.1 gHττ [%] 3.5 1.6 < 1.5 gHµµ [%] − 14 5.6 gHgg [%] 3.6 1.1 1.0 gHγγ [%] − 5.7 < 5.7 Parameter Measurement precision 350 GeV + 1.4 TeV +3.0 TeV 500 fb−1 +1.5 ab−1 +2.0 ab−1 ΓH,model [%] 1.6 0.29 0.22 κHZZ [%] 0.43 0.31 0.23 κHWW [%] 1.5 0.15 0.11 κHbb [%] 1.7 0.33 0.21 κHcc [%] 3.1 1.1 0.75 κHtt [%] − 4.0 4.0 κHττ [%] 3.4 1.3 < 1.3 κHµµ [%] − 14 5.5 κHgg [%] 3.6 0.76 0.54 κHγγ [%] − 5.6 < 5.6
Model-independent: Model-dependent (9/7 parameters):