1. Understanding Matter, Energy, Space and Time: The Case for the e  e  Linear Collider  Document produced at the instigation of the World Wide Study of Physics and Detectors in its meeting in Jeju Korea, August 2002. The writing group consisted of Takayuki Matsui, Sachio Komamiya, Francois Richard and Paul Grannis.

2. Preliminary versions of the document were made available to the worldwide linear collider community, and were discussed in regional meetings in Prague & Arlington TX. Numerous comments were received from the community and were incorporated into the current draft. Comments and responses by the writing committee are found on the web page: http://sbhep1.physics.sunysb.edu/~grannis/wwlc_report.html

3. What is this report intended to do? The hardest task was to come to some common understanding on who the document is aimed at. The audiences could be (a) HEP community (b) scientists outside high energy, (c) officials/staff of governments. Choose to make it a vehicle for HE physicists defining the case for the LC, in language comprehensible to scientists in allied disciplines. – succinctly stated and without specialized jargon, but not wholly oversimplified. At twelve pages of reasonably dense argument, it is inappropriate for use as a primary document for government officials. It could be of use as a supplementary document outlining the science goals and demonstrating worldwide support of HE community.

4. The WW Physics and Detector group believed that having a single document, subscribed to by a large number of physicists from around the world, would have the benefits: 1.A first coordinated attempt to state the case for the LC by individuals in all regions, and thus provide tangible evidence of the single-mindedness of the international community. 2.Provide the case for the LC from which simpler documents aimed at governments, the public, or other audiences could be drawn. 3.Outline the set of options that could be implemented, with the nature of the arguments that should shape the 'scope document' to follow. (This document does not attempt to define the priorities for the scope definition, but gives some guidance on how scenarios of emerging physics might shape the choice.) 4.Give the nature of LC detector requirements 5.Provide a basis for arguing the need for a LC that operates during the LHC era.

5. The premise is given in the introduction: A worldwide consensus has formed for a baseline LC with collision energies up to 500 GeV, luminosity above 10 34 cm -2 s -1, and electron polarization (>80%). We know enough to predict that this baseline LC will make key discoveries and measurements illuminating the nature of EWSB. Outline: 1.The scientific case for the Linear Collider 2.The Linear Collider facility 3.Linear Collider detectors 4.The international character of LC research 5.Conclusions  Where we stand today  Understanding the Higgs boson  New discoveries beyond the Standard Model  Benefit of precision measurements and interplay between LC and LHC  Cross connections ( & quark flavor, cosmology, astroparticle, RHI physics)

6. Key scientific points:  We know enough now to predict with great certainty that fundamental new understanding of how forces are related, and the way that mass is given to all particles, will be found with a linear collider operating at an energy of at least 500 GeV.  We are confident that the new physics that we expect beyond the standard model will be illuminated by measurements at both the LHC and the LC, through an intimate interplay of results from the two accelerators.  The physics investigations envisioned at the LC are very broad and fundamental, and will require a leading edge program of research for many years.

7. Figure intended to illustrate the ability of precision measurements to illuminate physics at a much higher scale: many found it either confusing or unnecessary. Eliminated in the present version.

8. Concluding bullets:  Scientific case rests on recent experiments; we are confident of discoveries at the LC  Concurrent LHC and LC operation needed to maximize discovery  Energy above 500 GeV will be needed ultimately  Two viable technological approaches exist  Several options (e  e , , e , positron polarization) would be beneficial, depending on physics. Retain flexibility to add.  State of the art detectors needed. R&D needed now  Inter-regional cooperation mechanisms now established. LC can be template for world collaborative projects

9. Next steps:  ILCSC endorsement (or recommendation to modify) this document.  Assemble names of signatories through the regional Physics and Detector Working Groups (list on the WW group web page referenced in document).  Proceed to a scope document using this as the basis for possible options.  Produce materials for governments, outreach etc. Should these be unified or regional/national?