1. F. Richard 26/11/101 Summary of LC Physics and Detector Workshop ECFA meeting at CERN F. Richard LAL/Orsay

2. F. Richard 26/11/102 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

3. 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 F. Richard 26/11/103

4. The attendance: 479 F. Richard 26/11/104 https://espace.cern.ch/LC2010/default.aspx

5. 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 1 st 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 Rolf F. Richard 26/11/105

6. 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) F. Richard 26/11/106

7. 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 3 evidence 125-500 GeV)  Light SUSY could be observed by LHC (improved evidence with recent g-2 update at 3.6 presented at this workshop by M. Davier)  Other discoveries are envisaged Z’, 4 th generation (suggested by Tevatron indications), … F. Richard 26/11/107

8. 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 tan=10 F. Richard 26/11/108

9. 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 F. Richard 26/11/109

10. 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 ? F. Richard 26/11/1010

11. 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 F. Richard 26/11/1011

12. Pflow optimisation at HE F. Richard 26/11/1012 M. Thomson

13. 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) ? F. Richard 26/11/1013

14. 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 F. Richard 26/11/1014

15. 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) F. Richard 26/11/1015

16. Conclusions  The ECFA study is helping to gather the LC effort, CLIC and ILC, in a unified way  This is a good 1 st 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 26/11/1016

17. Back up slides F. Richard 26/11/1017

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21. SiD’ & ILD’ F. Richard 26/11/1021

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