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Summary of LC Physics and Detector Workshop

ECFA meeting at CERN

F. Richard LAL/Orsay

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Outline Introduction What happened at IWLC2010, the International

Workshop on Linear Colliders held recently in Geneva (I will only cover briefly machine aspects)

Physics interrogations while LHC starts Prospects for CLIC and ILC How to improve on the organisation of these

wokshops Next workshops

Introduction IWLC2010 (October 18-22) is the first event with full

participation of CLIC and ILC on Machine and Detector aspects

This has some obvious good consequences: a joining of forces Machine+Detector+Physics towards a global project with good communication between participants

It however creates some practical problems since we need to use parallelism to accommodate all these activities - up to 16 // sessions - which sets constraints on possible choices for conference centers

For these reasons the meeting was split between CERN (two half days of full plenary sessions) and the Centre International de Conference of Geneva

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The attendance: 479  

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https://espace.cern.ch/LC2010/default.aspx

First day at CERN The workshop was preceded by a CERN colloquium by Steinar

as an introduction for the CERN staff In the spring of 2011, Steinar will become CERN LC Studies

Leader successor of Jean-Pierre Delahaye, current CLIC Study Leader

This change in title acknowledges that many activities are common between ILC and CLIC and expresses CERN's intention to work globally

There were overviews of physics, detector and machine activities on 1st day with a stimulating introduction by the CERN DG who insisted on the need for a global approach towards a LC and on the bright prospects offered by a good start of LHC

‘2012 could be a decisive year concerning LC’ says RolfF. Richard 26/11/10 5

Running scenarios Plenary session on the second day to

discuss running scenario: a LC needs to provide L~E from 200 GeV up to its maximum allowing for scans (SUSY, Higgs) in a reasonable time

Example of the Higgs threshold scan (20 fb-1/point)

Serious challenge for ILC (positrons) and CLIC (emittance preservation issue)

ILC recovers by operating at 10 Hz at low energy

CLIC has also provided a scheme (increased number of bunches)

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Discovery scenarios Quoting Rolf: ‘experimental results will dictate the agenda of

the field’ Session organized by G. Giudice and G. Weiglein from the POC Which LHC+Tevatron discovery scenarios and possible

influence on LC SM Higgs could be fully covered up to mH~500 GeV if LHC

runs in 2012 (exclusion or 3s evidence 125-500 GeV) Light SUSY could be observed by LHC (improved evidence

with recent g-2 update at 3.6s presented at this workshop by M. Davier)

Other discoveries are envisaged Z’ , 4th generation (suggested by Tevatron indications), …

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The SUSY issue What if we do not see SUSY with a few 1fb-1 : LC implications Only colored SUSY particle masses will be constrained (up to

~800 GeV within mSUGRA) Inferences about the color singlets relevant for LC are model

dependant (“gaugino universality”) says M. Peskin The relation mWino~1/3mGluino, is used in many benchmark

models, but it is an assumption, not well motivated theoretically introduced as a simplification of the large SUSY parameter space

Therefore it would be abusive to draw any conclusion on the energy needed for a LC from an absence of signal

g-2 indicates Msusy~200 GeV for sleptons & gauginos for tanb=10

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The Z’ case

What if we see a Z’ at 1.5 TeV or above?

Common prejudice is that we need to run on the pole

It has been shown that with high luminosity and beam polarisation one can learn a great deal on Z’ properties at lower energies

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ECFA SUMMARY TALKS (1) Last morning: summary of // sessions allowing an overview

+ 2 talks on MDI and IDAG (Advisory panel on detectors) Still very active on Higgs (ttH, ZHH challenging), SUSY, DM,

Top physics (impressive sensitivity of the LC to warped extra dimensions, few 10 TeV cf. R. Sundrum)

Loopverein and generators: very important to encourage these activities crucial to achieve adequate precision

Detector R&D is progressing very well: full physics prototypes to test feasibility, technological prototype to test integration (cooling, cabling, dead material, power pulsing etc…)

Issues: resources (urgent to create a European panel recognized by funding agencies), test beam in 2012 ?

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ECFA SUMMARY TALKS (2) MDI: push pull challenge with good ILC-CLIC synergy

(CLIC has chosen platforms) IDAG: advisory body for ILC detectors which has

examined the R&D program during this workshop Underlines that ILC R&D is not only beneficial to CLIC

but also to LHC (3D Si), superB (DEPFET), RHIC mimosa chip for STAR, T2K µmegas TPC, medical applications

Underlines lack of manpower for DBD (note that >50% of CLIC CDR editors come from SiD+ILD)

Detector performance: PFA improving W/Z separation up to 500 GeV by eliminating fake neutrals

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Pflow optimisation at HE

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M. Thomson

Last afternoon plenaries at CERN The prospects, the strategy CLIC: good progress in CTF3 and help from SiD+ILD on detectors

allows for a CDR in ~August 2011 ‘less increase for LC studies’ at CERN does not allow to define a

date for the TDR ILC: Progress on SCRF technology with an intense R&D around

the world (DESY et al., KeK, FNAL, Jefferson Lab…) Beautiful results from detector R&D with EU support (AIDA,

EUDET) TDR (machine) and DBD (Detectors) end of 2012 European strategy in 2011-2012: LC scenario to be defended

consistently by ILC & CLIC How to do this at the international level (ICFA) ?

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How to improve the workshop organization ?

Still too many working groups even after regrouping ‘artificially’ e.g. top, QCD, EW & Alternatives

Conveners not necessarily operating coherently Suggested solution: nominate a coordinator per cluster We may lose the effort coming from theory providing the

tools needed for precision measurement (Loopverein and Generator) if this activity does not receive more visibility

For the plenary sessions it is not easy to satisfy a general audience: theorists should avoid being too technical, the same applies to R&D talks, organizational aspects should not be discussed in too much detail

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Next Workshops Each year there is a regional and an international

workshop called LCWS and under the WWS-OC The worldwide-study-OC study has decided that, from

now on, CLIC (Machine+Detectors) can fully participate to the LCWS events

The CLIC Detector part would participate to regional workshops

Next regional conference ALCPG in Eugene Oregon (March 19-23 2011) http://physics.uoregon.edu/~lc/alcpg11/

LCWS11 in Granada 26-30 Sept 2011 (preliminary date)

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Conclusions The ECFA study is helping to gather the LC effort, CLIC

and ILC, in a unified way This is a good 1st step towards LC globalisation We should prepare ourselves in view of possible

discoveries at LHC/Tevatron (in time with the European Strategy in 2012)

IWLC2010, in spite of the complexity of the organisation, has been a success given the large and active participation of the LC community

Improvements are desirable for the ECFA study part with some feedback from the conveners

I wish to my successor a bright future on LC F. Richard 26/11/10 16

Back up slides

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SiD’ & ILD’

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