Physics : ILC vs LHC

Barbara Mele

Sezione di Roma

Roma, 12 ottobre 2005

….after Snowmass 2005

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Advances in Physics at Snowmass

Higgs

Supersymmetry

Beyond the Standard Model

Top / Quantum Chromodynamics

LHC/ILC Connections

Cosmological Connections

Radiative Corrections (Loopfest)

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The Charge for the Physics Working Groups

1. What are the most important measurements that the ILC should perform in the subject area of your working group?

2. What are the key measurements by which the ILC will add to what is already known from the LHC?

3. What are the processes and measurements new to the community

in the past few years that further motivate the case for the ILC?

4. For each of these measurements, what criteria for the detectors are necessary to allow measurements to the appropriate precision?

5. Are there detector capabilities that are not strongly challenged by

the list of processes in #1 and #2? Is this acceptable, or are there

additional measurements that should be added to the list against

which detectors will be evaluated?

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started in Spring 2002

485 pages !

~ 120 authors

. . .

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Precision Higgs physics at the ILC

• model-independent observation

• mass

• absolute branching ratios

• total width (mod.indep.)

• spin, CP

• top Yukawa coupling

• self coupling

most measurements at the percent level!

Garcia-Abia et al

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SupersymmetryTwo methods to obtain absolute sparticle masses:

in the continuum: at the kinematic threshold:

many more observables than just masses:

- angular distributions, FB-asymmetries- cross sections- LR-asymmetries- ratios of branching ratios

mass precision 0/00 – 0/0

possibility to determine SUSY parameters without many model assumptions

Martyn

Freitas

(polarized beams)

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Mass determination for 300fb-1 (thus 2014) LHC:Toy MC from edges, thresholds to masses

Polesello et al: use of χ1 from ILC (high precision) in LHC analyses improves the mass determination

LHC:LHC:

D. Zerwas, Snowmass talkAllanach et al

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MSSM parameter determination

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SUSY W-group conclusionsSUSY W-group conclusions

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DM/DM main sensitivity

bulk 3.5%

focus 1.9%

co-ann. 6.5%

funnel 3.1%

01 R R 1,e , ,

0 0 0 0 0 01 2 1 3 1 1 1 1 1, , , , ( )

0 01 1 1,

0 01 1A , ,

The Cosmic Connection

SUSY provides excellent candidate for dark matter (LSP)

Other models also provide TeV-scale WIMPs

How well can the properties of the DM-candidates (to be found ataccelerators) be compared to the properties of the real DM (inferred from astrophysical measurements) ?

ALCPG study/prel.

matches precision of future CMB exp.

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Dark Matter : is it the Susy LSP ?Dark Matter : is it the Susy LSP ?

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Difficult at LHC

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No elementary Higgs?Cross section for vector boson scattering violates unitarity at ~1.2 TeV, if forces remain weak and no new resonances appear

Birkedal et al.Krstonosic et al.

ILC sensitivity deep into multi-TeV region from VB final states

eff. Lagrangian parametersof strong EWSB:

Higgsless model: new resonancein WZWZ

Coupling structure from ILC if resonance seen by LHC

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Effective 4-fermion contact interactions

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What if “unexpected” New Physics ?

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Top

Hoang et al

it’s there for sure!Threshold scan provides excellentmass measurementTheory (NNLL) controls mt(MS) to 100 MeV

Heinemeyer et al

precise mtop vital for

- improved SM fits- MSSM (mh prediction)- DM-density in mSugra- . . . .

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EW precision measurements :

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Phisics Benchmarks for the ILC detectors

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