physics requirements

Physicsrequirementsatfuturecircularleptoncolliders

PhotoJ.Wenninger

PaoloGiacomelliINFNBologna

1

IAS workshop on tracking and calorimetry Hong Kong, 17/01/2019

ThankstoA.Blondel,P.Janot,R.Tenchini,F.Bedeschiandmanyothercollaborators

Physics requirements - Paolo Giacomelli 17/01/2019

Overview

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Overview

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The proposed future circular Lepton Colliders


Overview

!2


The FCC-ee and CEPC detector concepts


Overview

!2



Discovery potential


Overview

!2



Discovery potential

EW observables


Overview

!2



Discovery potential

EW observables

Higgs couplings


Overview

!2



Discovery potential

EW observables

Higgs couplings

Detector requirements


Overview

!2



Discovery potential

EW observables

Higgs couplings


Conclusions


Overview

!2



Discovery potential

EW observables

Higgs couplings


Conclusions

A lot more information from the 11th FCC-ee workshop of last week, https://indico.cern.ch/event/766859/timetable/

https://indico.cern.ch/event/766859/timetable/


Overview

!2



Discovery potential

EW observables

Higgs couplings


Conclusions

Caveat




Overview

!2



Discovery potential

EW observables

Higgs couplings


Conclusions

CaveatCannot possibly cover all the physics landscape!




Overview

!2



Discovery potential

EW observables

Higgs couplings


Conclusions

CaveatCannot possibly cover all the physics landscape!

A personal selection applied…



17/01/2019 Physics requirements - Paolo Giacomelli

From European Strategy in 2013: “ambitious post-LHC accelerator project” Study kicked-off in Geneva in Feb 2014

The Future Circular Colliders CDR and cost review to appear Q4 2018 for ESU

International collaboration to Study Colliders fitting in a new ~100 km infrastructure, CERN as host lab

• Ultimate goal: 100 TeV pp-collider (FCC-hh)

à defining infrastructure requirements

• e+e- collider (FCC-ee) High Lumi, ECM =90-400 GeV

As potential first step

• HE-LHC 16T ⇒ 27 TeV in LEP/LHC tunnel

Possible addition: • p-e (FCC-he) option

~16 T magnets

!3











~16 T magnets

Fromwhatweknowtoday:thewaybyFCC-eeisprobablythefastestandcheapestwayto100TeV.Thatcombinationalsoproducesthemostphysics.Itistheassumptioninthefollowing.

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~16 T magnets

Fromwhatweknowtoday:thewaybyFCC-eeisprobablythefastestandcheapestwayto100TeV.Thatcombinationalsoproducesthemostphysics.Itistheassumptioninthefollowing. alsoagoodstartforµC!

!3


Possible Timeline of the FCCs

!4

Technical Schedule for each of the 3 options20 22 24 26 28 30 32 34 38 40

Civil Engineering FCC-hh ring

Dipole short models

16 T dipole indust. prototypes16 T dipoles preseries

16 T series productionSC M

agne

ts

CE FCC-ee ring + injector

FCC-

hhFC

C-ee

HE-L

HC

Strategy Update 2026 – assumed project decision

Installation HE-LHC

LHC Modification

42

Technical Design Phase

36

Installation + test FCC-ee

Installation + test FCC-hh

CE TL to LHC

LHC Removal

Dipole long models

Injector

16Tmagnets

FCC-hh

FCC-ee

HE-LHC

schedule constrained by 16 T magnets & CE → earliest possible physics starting dates • FCC-ee: 2039 • FCC-hh: 2043 • HE-LHC: 2040 (with HL-LHC stop LS5 / 2034)


Circular colliders: CEPC

!5

Center of mass energy 91 - 240 GeV Max. luminosity (√s=240 GeV) 3 x 1034 cm-2s-1 Later install SPPC (pp collider) √s = 100-120 TeV

CEPC booster ring (100km)CEPC collider ring (100km)

Higgs,W,andZmodes

Syncrotron Radiation power 30MW/ beam, upgradable to 50MW/beam

CDR published in November 2018


Circular colliders: CEPC

!5

Center of mass energy 91 - 240 GeV Max. luminosity (√s=240 GeV) 3 x 1034 cm-2s-1 Later install SPPC (pp collider) √s = 100-120 TeV

CEPC booster ring (100km)CEPC collider ring (100km)

Higgs,W,andZmodes

Syncrotron Radiation power 30MW/ beam, upgradable to 50MW/beam


CEPC could start operations in the early

2030s


Circular colliders: FCC-ee detectors

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!6

CLD2 T solenoid Full Si tracker SiW HG EM calorimeter Sci.-steel HG HCAL calorimeter Muon detector with RPCs



!6

IDEA

2 T thin solenoid Si vertex Wire chamber Dual Readout calorimeter MPGD-based Muon detector




!6

CDR to be published in January 2019

IDEA

2 T thin solenoid Si vertex Wire chamber Dual Readout calorimeter MPGD-based Muon detector



Circular colliders: CEPC detectors

!7



!7

PFA oriented concept with high granularity calorimeter + TPC 3 T solenoid

ILD-like



!7


ILD-like

IDEA



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ILD-like

IDEA


Future lepton colliders luminosities

!8

Clear advantage in luminosity for circular colliders vs. linear colliders. Linear colliders (CLIC) have higher energy reach, but less than a pp collider.

√s (GeV)

HWWZ tt

Tota

l lum

inos

ity [1

034 c

m-2

s-1 ]


FCC-ee Run Plan

!9

Workingpoint nominalluminosity/IP[1034cm-2s-1]

totalluminosity(2IPs)/yrhalfluminosityinfirsttwo

years(Z)andfirstyear(ttbar)toaccountforinitialoperation

physicsgoal runtime[years]

Zfirst2years 100 26ab-1/year150ab-1 4

Zlater 200 48ab-1/yearW 25 6ab-1/year 10ab-1 2H 7.0 1.7ab-1/year 5ab-1 3machinemodificationforRFinstallation&rearrangement:1yeartop1styear(350GeV) 0.8 0.2ab-1/year 0.2ab-1 1toplater(365GeV) 1.4 0.34ab-1/year 1.5ab-1 4

totalprogramduration:15years-includingmachinemodificationsphase1(Z,W,H):9years,phase2(top):6years


FCC-ee Run Plan

!9

Eventstatistics:

ZpeakEcm:91GeV5x1012e+e-àZWWthresholdEcm:161GeV108e+e-àWWZHthresholdEcm:240GeV106e+e-àZH�ttthresholdEcm:350GeV106e+e-à�tt

LEPx105LEPx2.103NeverdoneNeverdone

100keV300keV1MeV2MeV

ECMerrors:

Workingpoint nominalluminosity/IP[1034cm-2s-1]

totalluminosity(2IPs)/yrhalfluminosityinfirsttwo

years(Z)andfirstyear(ttbar)toaccountforinitialoperation

physicsgoal runtime[years]

Zfirst2years 100 26ab-1/year150ab-1 4

Zlater 200 48ab-1/yearW 25 6ab-1/year 10ab-1 2H 7.0 1.7ab-1/year 5ab-1 3machinemodificationforRFinstallation&rearrangement:1yeartop1styear(350GeV) 0.8 0.2ab-1/year 0.2ab-1 1toplater(365GeV) 1.4 0.34ab-1/year 1.5ab-1 4

totalprogramduration:15years-includingmachinemodificationsphase1(Z,W,H):9years,phase2(top):6years


FCC-ee discovery potential

!10

q EXPLORE the 10-100 TeV energy scale

u With precision measurements of the properties of the Z, W, Higgs, and top particles

l 20-50 fold improved precision on ALL electroweak observables (EWPO)

è mZ , GZ , mW , mtop , sin2 qweff, Rb , aQED (mz), as (mz), top EW couplings …

l 10 fold more precise Higgs couplings measurements

è Break model dependence with GH accurate measurement

q DISCOVER that the Standard Model does not fit

u Then extra weakly-coupled and Higgs-coupled particles exist

u Understand the underlying physics through effects via loops

q DISCOVER a violation of flavour conservation / universality

u e.g., with B0 → K*0t+t- or BS→ t+t- in 1012 bb events

q DISCOVER dark matter as invisible decays of Higgs or Z

q DISCOVER very weakly coupled particles in the 5-100 GeV mass range

u Such as right-handed neutrinos, dark photons, …

l May help understand dark matter, universe baryon asymmetry, neutrino masses

NBNotonlya«HiggsFactory»,«Zfactory»and«top»areimportantfor‘discoverypotential’

Todaywedonotknowhownaturewillsurpriseus.AfewthingsthatFCC-eecoulddiscover:


EW observables at the Z

!11

From data collected in a lineshape energy scan:• Z mass (key for jump in precision for ewk fits)• Z width (jump in sensitivity to ewk rad corr)• Rl = hadronic/leptonic width (αs(mZ2), lepton couplings)• peak cross section (invisible width, Nν)• AFB(µµ) (sin2 θeff , αQED(mZ2), lepton couplings)• Tau polarization (sin2 θeff , lepton couplings, αQED(mZ2))• Rb, Rc, AFB(bb), AFB(cc) (quark couplings)

Roberto Tenchini

5x1012e+e-àZ


Determination of mZ and ΓZ

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• Uncertainty on mZ (≈ 100 KeV) is dominated by the correlated uncertainty on the centre-of-mass energy at the two off peak points

At FCC-ee continuous Ecm calibration (resonant depolarisation) gives ΔEcm ≈ 10 KeV (stat) + 100 KeV (syst)

• the off peak point-to-point anti-correlated uncertainty has a similar impact (≈ 100 KeV) on ΓZ

Requirements on the detector are not crucial for these two measurements, but should not be forgotten either: excellent control of acceptance over √s is important. For a detector and simulations a la LEP the impact was O(100 KeV).

Roberto Tenchini


Beam energy spread with µ+µ-

!13

FCC-ee: Asymmetric optics withbeam crossing angle α of 30 mrad• α is measured in e+e-àµ+µ-(γ)

together with γ (ISR) energy, both distributions sensitive to energy spread.• Energy spread measured at 0.1% with 106 muons (4 min at FCC-ee)• Current calculations of ISR emission spectrum sufficient• Detector requirement on muon angular resolution 0.1 mrad

Patrick Janot

Roberto Tenchini

Can keep related systematicuncertainty on ΓZ at less than 30 keV

BS=beamstrahlung


Luminosity measurements and σhad

!14


Tau polarization

!15


EW observables at W+W-

!16

Roberto Tenchini

108e+e-àWW

From data collected around and above the WW threshold:• W mass (key for jump in precision for ewk fits)• W width (first precise direct measurement)• RW = Γhad/Γlept (αs(mZ2))• Γe , Γµ , Γτ (precise universality test )• direct CKM measurements (with jet-flavor tagging)• Triple and Quartic Gauge couplings (jump inprecision, especially for charged couplings)


W mass and width from WW cross-section

!17


EW observables at FCC-ee

Observable Measurement Currentprecision TLEPstat. Possiblesyst. Challenge

mtop(MeV) Thresholdscan 173340±760±500 20 <40 QCDcorr.

Γtop(MeV) Thresholdscan ? 40 <40 QCDcorr.

λtop Thresholdscan µ=1.2±0.3 0.08 <0.05 QCDcorr.

ttZcouplings √s=365GeV ~30% ~2% <2% QCDcorr


mw(MeV) Thresholdscan 80385±15 0.6 <0.6 EWCorr.

ΓW(MeV) Thresholdscan 2085±42 1.5 <1.5 EWCorr.

Nν e+e−→γZ,Z→νν,ll 2.92±0.05 0.001 <0.001 ?

αs(mW) Bhad=(Γhad/Γtot)W Bhad=67.41±0.27 0.00018 <0.0001 CKMMatrix

Observable Measurement Currentprecision FCC-eestat. Possiblesyst. Challenge

mZ(MeV) Lineshape 91187.5±2.1 0.005 <0.1 QEDcorr.

ΓZ(MeV) Lineshape 2495.2±2.3 0.008 <0.1 QED/EW

Rl Peak 20.767±0.025 0.001 <0.001 Statistics

Rb Peak 0.21629±0.00066 0.000003 <0.00006 g→bb

Nν Peak 2.984±0.008 0.00004 <0.004 Lumimeast

sin2θWeff AFBµµ (peak) 0.23148±0.00016 0.000003 <0.000005 Beamenergy

1/αQED(mZ) AFBµµ (off-peak) 128.952±0.014 0.004 <0.004 QED/EW

αs(mZ) Rl 0.1196±0.0030 0.00001 <0.0002 NewPhysics

*

*

*worktodo:checkifwecanimprove!18


EW observables at FCC-ee


mtop(MeV) Thresholdscan 173340±760±500 20 <40 QCDcorr.

Γtop(MeV) Thresholdscan ? 40 <40 QCDcorr.

λtop Thresholdscan µ=1.2±0.3 0.08 <0.05 QCDcorr.

ttZcouplings √s=365GeV ~30% ~2% <2% QCDcorr


mw(MeV) Thresholdscan 80385±15 0.6 <0.6 EWCorr.

ΓW(MeV) Thresholdscan 2085±42 1.5 <1.5 EWCorr.

Nν e+e−→γZ,Z→νν,ll 2.92±0.05 0.001 <0.001 ?

αs(mW) Bhad=(Γhad/Γtot)W Bhad=67.41±0.27 0.00018 <0.0001 CKMMatrix

Observable Measurement Currentprecision FCC-eestat. Possiblesyst. Challenge

mZ(MeV) Lineshape 91187.5±2.1 0.005 <0.1 QEDcorr.

ΓZ(MeV) Lineshape 2495.2±2.3 0.008 <0.1 QED/EW

Rl Peak 20.767±0.025 0.001 <0.001 Statistics

Rb Peak 0.21629±0.00066 0.000003 <0.00006 g→bb

Nν Peak 2.984±0.008 0.00004 <0.004 Lumimeast

sin2θWeff AFBµµ (peak) 0.23148±0.00016 0.000003 <0.000005 Beamenergy

1/αQED(mZ) AFBµµ (off-peak) 128.952±0.014 0.004 <0.004 QED/EW

αs(mZ) Rl 0.1196±0.0030 0.00001 <0.0002 NewPhysics

*

*

*worktodo:checkifwecanimprove!18

Great improvement across all th

e measurements !


Detector requirements at Z, WW

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!19

Very precise knowledge of beam spread!



!19

Very precise knowledge of beam spread!Can be done with µ+µ- events



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For all cross-sections Luminometer precision!



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For all cross-sections Luminometer precision!Acceptance known to ~2µm



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Many measurements require detector acceptance ~5 times better than LEP



!19




Acceptance of low p objects must be kept high



!19




Acceptance of low p objects must be kept high Good π0 identification and direction



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Acceptance of low p objects must be kept high Good π0 identification and directionb/c-tagging much better than LHC



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High efficiency and purity, little p dependence



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High efficiency and purity, little p dependence

Due to extreme statistics, the requirements at the Z are the most demanding ones



!20

Franco Bedeschi



!20

Additionally:

Franco Bedeschi



!20

Additionally:

Δpt/pt2 ~ 10-4 (GeV-1) or better

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possible

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentum

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentumHadron calorimeter must allow particle flow

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentumHadron calorimeter must allow particle flowIdentification of secondary vertices similar and better than modern LHC detectors

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentumHadron calorimeter must allow particle flowIdentification of secondary vertices similar and better than modern LHC detectorsExcellent lepton ID

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentumHadron calorimeter must allow particle flowIdentification of secondary vertices similar and better than modern LHC detectorsExcellent lepton IDGood tracking up to large distance from IP (LLP)

Franco Bedeschi



!20

Additionally:


Tracker must be as light as possibleHigh efficiency down to low momentumHadron calorimeter must allow particle flowIdentification of secondary vertices similar and better than modern LHC detectorsExcellent lepton IDGood tracking up to large distance from IP (LLP)Detector hermeticity (for missing energy)

Franco Bedeschi


Detector requirements for HF

!21

Franco Bedeschi

❖ Vertexing: ➢ Direction of secondary

requires extreme resolution ➢ With ILD can resolve

B0 à Κ∗0 τ+τ−

❖ Momentum resolution ➢ cLFV

p resolution at the level of the beam energy spread Δpt/pt2 ~ 2-4x10-5 (GeV-1)



!22

Franco Bedeschi



!22

❖ Hadronic PID

Franco Bedeschi



!22

❖ Hadronic PID➢ Example BsàDs K for CP violation studies

Franco Bedeschi



!22

❖ Hadronic PID➢ Example BsàDs K for CP violation studies➢ Plot is after LHCb PID

Franco Bedeschi



!22

❖ Hadronic PID➢ Example BsàDs K for CP violation studies➢ Plot is after LHCb PID➢ Many other applications

Franco Bedeschi



!22


❖ Calorimetry

Franco Bedeschi



!22


❖ Calorimetry➢ High granularity

Franco Bedeschi



!22


❖ Calorimetry➢ High granularity➢ PID in jets

Franco Bedeschi



!22


❖ Calorimetry➢ High granularity➢ PID in jets➢ Good resolution

Franco Bedeschi


FCC-ee

240 GeV

FCC-ee

365 GeV

Total Integrated Luminosity (ab-1) 5 1.5

# Higgs bosons from e+e-→HZ 1,000,000 180,000

# Higgs bosons from fusion process 25,000 45,000

FCC-ee 5 ab-1@240 GeV ~1.5 ab-1@365 GeV

Higgs Factory!

!23

Higgs production at FCC-ee


Higgs production at an e+e- collider

“Higgstrahlung” process close to threshold

Production cross section has a maximum at near threshold ~200 fb

1034/cm2/s ➔ 20’000 HZ events per year

!24

For a Higgs of 125 GeV, a centre of mass energy of 240-250 GeV is optimal ➔ kinematical constraint near threshold for high precision in mass, width, selection purity

Z – tagging by missing mass


Higgs couplings to Z➡ Recoil method provides a unique opportunity for a decay-mode

independent measurement of the HZ coupling Higgs events are tagged with the Z boson decays, independently of Higgs decay mode, mrecoil = mH

Expected precision 0.7% on the ZH cross section

Using only leptonic Z decays and only a measurement at 240 GeV so far

!25

Higgs-strahlung


Higgs boson width➡ Total Higgs boson width can be extracted from a

combination of measurements in a model independent way 1) tagging Higgs final states

2) measurements of vector boson fusion production at 365 GeV

3) combination of all measurements

!26

Precision obtainable on δΓH/ΓH ~ 1.6%


Higgs boson couplings➡ Precision Higgs coupling measurements

Absolute coupling measurements enabled by HZ cross section and total width measurement

Data at 365 GeV constrain total width

only used H→bb in fusion production so far

Tagging individual Higgs final states to extract various Higgs couplings

Couplings extracted from model-independent fit

Statistical uncertainties are shown for 5 ab-1@240 GeV and 1.5 ab-1@365 GeV (from arXiv:1308.6176)

๏ all measurements are under review / are being redone

๏ possible improvements of 10-35% on cross section measurements

!27

in % FCC-ee 240 GeV

+FCC-ee 365 GeV +HL-LHC

δgHZZ 0.25 0.22 0.21δgHWW 1.3 0.47 0.44δgHbb 1.4 0.68 0.58δgHcc 1.8 1.23 1.20δgHgg 1.7 1.03 0.83δgH𝛕𝛕 1.4 0.8 0.71δgHμμ 9.6 8.6 3.4δgH𝛄𝛄 4.7 3.8 1.3δgHtt 3.3δΓH 2.8 1.56 1.3

Several couplings improve further by doing a combined fit with HL-LHC


Comparison with other e+e- colliders

!28

Collider µColl125 ILC250 CLIC380 LEP3240 CEPC250 FCC-ee240 FCC-ee365

Years 6 15 7 6 7 3 4

Lumi(ab-1) 0.005 2 0.5 3 5 5 1.5

δmH(MeV) 0.1 14 110 10 5 7 6

δΓH/ΓH(%) 6.1 3.8 6.3 3.7 2.6 2.8 1.6

δgHb/gHb(%) 3.8 1.8 2.8 1.8 1.3 1.4 0.68

δgHW/gHW(%) 3.9 1.7 1.3 1.7 1.2 1.3 0.47

δgHτ /gHτ (%) 6.2 1.9 4.2 1.9 1.4 1.4 0.80

δgHγ /gHγ(%) n.a. 6.4 n.a. 6.1 4.7 4.7 3.8

δgHµ /gHµ(%) 3.6 13 n.a. 12 6.2 9.6 8.6

δgHZ/gHZ(%) n.a. 0.35 0.80 0.32 0.25 0.25 0.22

δgHc/gHc(%) n.a. 2.3 6.8 2.3 1.8 1.8 1.2

δgHg/gHg(%) n.a. 2.2 3.8 2.1 1.4 1.7 1.0

BRinvis(%)95%CL SM <0.3 <0.6 <0.5 <0.15 <0.3 <0.25

BREXO(%)95%CL SM <1.8 <3.0 <1.6 <1.2 <1.2 <1.1

Green = bestRed = worst


Comparison with other e+e- colliders

!28

Collider µColl125 ILC250 CLIC380 LEP3240 CEPC250 FCC-ee240 FCC-ee365

Years 6 15 7 6 7 3 4

Lumi(ab-1) 0.005 2 0.5 3 5 5 1.5

δmH(MeV) 0.1 14 110 10 5 7 6

δΓH/ΓH(%) 6.1 3.8 6.3 3.7 2.6 2.8 1.6

δgHb/gHb(%) 3.8 1.8 2.8 1.8 1.3 1.4 0.68

δgHW/gHW(%) 3.9 1.7 1.3 1.7 1.2 1.3 0.47

δgHτ /gHτ (%) 6.2 1.9 4.2 1.9 1.4 1.4 0.80

δgHγ /gHγ(%) n.a. 6.4 n.a. 6.1 4.7 4.7 3.8

δgHµ /gHµ(%) 3.6 13 n.a. 12 6.2 9.6 8.6

δgHZ/gHZ(%) n.a. 0.35 0.80 0.32 0.25 0.25 0.22

δgHc/gHc(%) n.a. 2.3 6.8 2.3 1.8 1.8 1.2

δgHg/gHg(%) n.a. 2.2 3.8 2.1 1.4 1.7 1.0

BRinvis(%)95%CL SM <0.3 <0.6 <0.5 <0.15 <0.3 <0.25

BREXO(%)95%CL SM <1.8 <3.0 <1.6 <1.2 <1.2 <1.1

Green = bestRed = worst

FCC-ee and CepC have a clear edge over linear colliders


Higgs requirements

!29

• Track momentum resolution • Beam energy spread • Z decay width • EM energy resolution • Separation of ZZ/WW 4-jet

final states • Excellent Jet energy

resolution


Detector requirements for Higgs

!30

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)

σ(E)/E~10%/√E EM energy resolution

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)

σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E for jet energy resolution

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)

σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E for jet energy resolution Flavor tagging

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)


Decay length

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)


Decay lengthJet kinematic variables

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)


Decay lengthJet kinematic variablesSemi-leptonic decays

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)



Excellent b/c separation (much better than LHC detectors)

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)



Excellent b/c separation (much better than LHC detectors)PID for π+- separation from other particles

Krisztian Peters



!30

Δpt/pt2 ~ 2x10-5 (GeV-1)



Excellent b/c separation (much better than LHC detectors)PID for π+- separation from other particlesLow energy π0 reconstruction

Krisztian Peters


Conclusions

!31


Conclusions

!31

Huge statistics of Z, W+W-, H and ttbar pair events will allow:


Conclusions

!31

Huge statistics of Z, W+W-, H and ttbar pair events will allow:20-50 improvements on all EW observable measurements


Conclusions

!31

Huge statistics of Z, W+W-, H and ttbar pair events will allow:20-50 improvements on all EW observable measurementsMeasure Higgs couplings to ~1% level or better


Conclusions

!31

Huge statistics of Z, W+W-, H and ttbar pair events will allow:20-50 improvements on all EW observable measurementsMeasure Higgs couplings to ~1% level or betterDiscover possible deviations from the SM


Conclusions

!31

Huge statistics of Z, W+W-, H and ttbar pair events will allow:20-50 improvements on all EW observable measurementsMeasure Higgs couplings to ~1% level or betterDiscover possible deviations from the SMmuch more…


Conclusions

!31


To achieve these unprecedented results extremely precise detectors are needed:


Conclusions

!31



Luminometer acceptance of ~2µm


Conclusions

!31



Luminometer acceptance of ~2µmExcellent detector acceptance down to low p objects


Conclusions

!31



Luminometer acceptance of ~2µmExcellent detector acceptance down to low p objectsΔpt/pt

2 ~ 2-4x10-5 (GeV-1)


Conclusions

!31




2 ~ 2-4x10-5 (GeV-1)σ(E)/E~10%/√E EM energy resolution


Conclusions

!31




2 ~ 2-4x10-5 (GeV-1)σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E jet energy resolution


Conclusions

!31




2 ~ 2-4x10-5 (GeV-1)σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E jet energy resolution Hadron calorimeter with particle flow capability


Conclusions

!31




2 ~ 2-4x10-5 (GeV-1)σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E jet energy resolution Hadron calorimeter with particle flow capability Excellent b/c separation and PID over a large p range


Conclusions

!31




2 ~ 2-4x10-5 (GeV-1)σ(E)/E~10%/√E EM energy resolutionσ(E)/E~30%/√E jet energy resolution Hadron calorimeter with particle flow capability Excellent b/c separation and PID over a large p rangeVery accurate knowledge of beam energy spread

17/01/2019 Physics requirements - Paolo Giacomelli !32

Backup


ΓZ and beam energy spread

!33


Partial width ratio (Rl)

!34


❑ Basicmeasurementssimilarforalle+e−colliders◆ Somedifferencesinexperimentalconditions

◆ e+e−→HZat√s=240-250GeV:HiggsbosonaretaggedwithaZandmRecoil=mH

● MeasureσHZ(∝ gHZ2)independentlyofHdecay:absolutedeterminationofgHZ

● MeasureσHZ×BR(H→invisible)andmanyexclusivedecaysσHZ×BR(H→XX)● InferHiggswidthΓHfromσHZ×BR(H→ZZ)(∝gHZ

4/ΓH)● FitcouplingsgHXfromBR(H→XX)andΓHinamodel-independentmanner

◆ e+e−→HZcompletedwithWWfusionat√s=350-365GeVatFCC-ee● Improvesallprecisions,especiallyongHWandΓH● FirstglanceattopYukawacouplingλtandHiggsselfcouplingλH(nextslides)

Circular e+e- colliders: FCC-ee, CepC

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e+e−→ HZ

µ+

µ−


totalrate∝ gHZZ2ZZZfinalstate∝ gHZZ4/ΓH➔ measuretotalwidthΓH

gHZZto±0.2%andmanyotherpartialwidthsemptyrecoil=invisiblewidth‘funnyrecoil’=exoticHiggsdecayeasycontrolbelowthreshold

Z-tagging by missing mass

e+

e-

Z*

Z

H

!36


Higgs self-coupling

❑ √sdependenceofthe“effective”gHZandgHWtotheHiggsself-coupling

◆ Accessiblefromthehigh-precisionrunsat240,(350),and365GeV

● ArisingfromHiggs-triangleand-loopdiagrams

●

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➡ Very large HZ datasets allow gZH measurements of extreme precision

➡ Indirect and model-dependent probe of Higgs self-coupling

A precision on δκλ of ±40%

can be achieved, and of ±35% in combination with HL-LHC. If cZ if fixed to its SM value, then the precision on δκλ

improves to ±20%

physics requirements

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