Last week the 2005 International Linear Collider Workshop was held at SLAC, and the talks are available on-line. At the conference it was announced that Barry Barish of Caltech would lead the Global Design Effort for the International Linear Collider. The hope is to finish a design for the ILC in 2007, have a site chosen in 2008 and construction done by 2015, allowing the ILC to run at the same time as the LHC for several years, with each machine providing data that could help decide how best to use the other one.
This schedule seems overly optimistic to me. Because of the huge US deficits, getting the kinds of increases in the DOE budget needed to build the ILC in the US looks quite difficult, and, even if this were possible, funding constraints would probably stretch out the construction schedule. In Europe, CERN is devoting all its resources for a while to the LHC, and is backing an alternate, more speculative linear collider technology called CLIC. The most likely course of events seems to be that people will be waiting to see what the LHC finds and how the CLIC technology works out before fully committing to a new linear collider. If so, a decision about what to build and where to build it would probably not take place until almost 2010, with another decade probably required to actually construct the machine.
At the SLAC conference, the main theoretical talk was one by Savas Dimopoulos on New Models about his work with Arkani-Hamed on split supersymmetry and models where both the cosmological constant and the weak scale are anthropically determined aspects of the “Landscape”. There increasingly seems to be a disconnect between the experimentalists planning experiments at the LHC and ILC, whose plans often revolve around the search for low-energy supersymmetry, and the string theory inspired theorists, who are spending their time wandering around the landscape. From the landscape point of view, it seems that low-energy supersymmetry is extremely unlikely.
For more from theorists wandering around the landscape, see the talks at this week’s Workshop on N=1 Compactications at the Fields Institute in Toronto. The talks from this workshop are starting to become available on-line. Next week there will be even more of this at the Fields Institute, as it hosts a Workshop on String Phenomenology.