FZÚ, 12.5.2005 J. Cvach, LCWS05 2
The TeV ILC planned for 2015
• Parameters defined by ILCSC scope-panel for ITRPhttp://www.fnal.gov/directorate/icfa/LC_parameters.pdf
• Baseline s = 200-500 GeV, • integrated luminosity = 500 fb-1 over 1st 4 years• 80% electron polarisation• 2 interaction regions with easy switching
• Upgrade Anticipate s 1 TeV, = 1 ab-1 over 4 years
• Options e-e- collisions, • 50% positron polarisation,• “GigaZ”; high at Z and at WW threshold,• Laser backscatter for and e collisions,• Doubled at 500 GeV.• Choice among options to be guided by physics needs.
FZÚ, 12.5.2005 J. Cvach, LCWS05 3
Physics at the LHC and ILC in a nutshell
LHC: pp scattering at 14 TeV
Scattering process of protonconstituents with energy up toseveral TeV,strongly interacting huge QCD backgrounds,
low signal-to-backgroundratios
ILC: e+e- scattering at ≈ 0.5-1 TeV
Clean experimental environment:• well-defined initial state,• tuneable energy,• beam polarization, GigaZ
γγ, γe-, e-e- options, . . . relatively small backgrounds
high-precision physics
FZÚ, 12.5.2005 J. Cvach, LCWS05 4
Why?
2001; mt=174.3 5.1; PDG
2004; mt=178.0 4.3
Moves best fit mH
by > 20 GeV. Very sensitive.
Recent illustration; D0’s new mt measurement
Because precision on mt limits current SM fit.
Definite job to be done.Measure mt to < 100 MeV
FZÚ, 12.5.2005 J. Cvach, LCWS05 8
Higgs na ILC
Hlavní mechanismy pro produkci Higgse :
a) Higgs strahlung (dominuje pro malé MH)
b) W fusion (dominuje pro velké MH)
FZÚ, 12.5.2005 J. Cvach, LCWS05 9
500 fb-1 at350 GeV
Constrained fits to final states
0
120HM GeV
H Z bbqq
0
120HM GeV
H Z bbl l
0
150HM GeV
H Z W W qq
0
150HM GeV
H Z W W l l
Higgs mass measurement
FZÚ, 12.5.2005 J. Cvach, LCWS05 11
The Recoil Measurement
Higgs mass and cross section in e+e- Z X e+e- X (μ+μ- X)• Study of SM Higgs sensitivity at ILC - full simulation
(MOKKA)!• work in progress
Event display: h0 Z0 b bbar μ+ μ-
Particle Flow in Reconstruction The Invariant Mass of Invisible System (the Recoil Mass Method) Including the ISR
SM Higgs Signal Reconstruction Z μ+ μ- Final State 100 fb-1
SM Higgs Signal Reconstruction Z e+e- Final State 100 fb-1
FZÚ, 12.5.2005 J. Cvach, LCWS05 12
ILC Charge in Higgs Physics
At the ILC, we can do an inclusive measurement of Higgs production:
e+e- H + X (recoil spectrum)
This removes the model dependence from all LHC (and ILC) coupling measurements.
• At the ILC, we can determine couplings to better than 5 %. In particular, can be precisely measured.
Leaving the minimal SM paradigm, there is another crucial point:
• At the ILC, we can detect extra scalars in the Higgs sector (if not too heavy), complementing LHC searches. Many of their properties can be determined.
Finally:
• At the ILC, the Higgs self-coupling can be measured (with low precision), if the Higgs is not too heavy. (For a Higgs boson above the WW threshold, this is more accessible at the LHC.)
H→bb
FZÚ, 12.5.2005 J. Cvach, LCWS05 13
"Known unknowns" vs. "unknown unknowns"
ILC will be prepared to explore Higgs physics, SUSY, extra dimensions, mini black holes, . . .
These are „known unknowns“, but one also needs to be prepared for the unexpected
LHC: interaction rate of 109 events/s
can trigger on only 1 event in 107
ILC: untriggered operation
can find signals of unexpected new physics (direct production + large indirect reach) that manifests itself in events that are not selected by the LHC trigger strategies
FZÚ, 12.5.2005 J. Cvach, LCWS05 14
Práce skupiny LHC/ILC: hep-ph/0410364
The intimate interplay of the results of the two collider facilities will allow one to probe, much more effectively and more conclusively than each machine separately, the fundamental interactions of nature and the structure of matter, space and time.
Results from both colliders will be crucial in order to decipher the underlying physics in the new territory that lies ahead of us and to draw the correct conclusions about its nature. This information will be decisive for guiding the way towards effective experimental strategies and dedicated searches. It will not only sharpen the goals for a subsequent phase of running of both LHC and LC, but will also be crucial for the future roadmap of particle physics.
The interplay between LHC and LC is a very rich field, of which only very little has been explored so far.
FZÚ, 12.5.2005 J. Cvach, LCWS05 15
Positron (polarised) source
• Both beams polarized– Different production mechanisms in s, t channels– In case of MSSM – charge of observed lepton directly
related to L, R quantum no. of the selectron• e-
L,R ẽ-L,R and e+
L,R ẽ+L,R
– Smaller background to physical processes
• Large amount of charge to produce• Three concepts:
– undulator-based (TESLA TDR baseline)– ‘conventional’ (extrapolation from SLC e+ source)– laser Compton based
FZÚ, 12.5.2005 J. Cvach, LCWS05 16
Undulator-Based
6D e+ emittance small enough that (probably) no pre-DR needed [shifts emphasis/challenge to DR acceptance]
Lower n production rates (radiation damage)
Need high-energy e- to make e+ (coupled operation) Makes commissioning more difficult
Polarised positrons (almost) for free