John Womersley is since the beginning of October the new Director of Particle Physics at the Rutherford Appleton Lab (see announcement)
How do you see the interplay between LHC/ILC?
There's a strong physics interplay. We have very good reason to believe that there is a rich world of new phenomena that can be explored with TeV scale accelerators. The LHC will blaze a trail into this new world, but by itself will leave us more questions than answers (and that's a good thing, in science). The ILC is the right tool to answer many of those open issues. For example, is a particle found at the LHC really the Higgs boson - does it have the right couplings to other particles to give them mass? Are the new particles that may have been discovered really related to the existing ones through supersymmetry - do they have the same couplings and different spins? And does any new, weakly interacting particle have the right properties to account for cosmic dark matter?
Coming from an hadron collider, how do you see the physics at a lepton collider?
My heart enjoys hadron colliders - the thrill of pushing to the highest energies, the possbility of being the first to glimpse new phenomena, of blazing the first trail through the jungle. But increasingly my head has come to appreciate the beautiful precision that is possible at a lepton collider, for example to measure spins and couplings, and the potential that this has to provide an understanding of the underlying symmetries and laws of nature.
How do you see the current role of the UK in the LC R&D?
Even from across the Atlantic, it is clear that the UK is playing a strong role in LC R&D. UK physicists are prominent within the Global Design Effort and were very visible at the recent Snowmass meeting. Among other things, they are working on the interaction point design, machine-detector interface issues, and detector development. I am very pleased that my own department hosts one of the leading groups in developing vertex detectors for the ILC through the LCFI project.
Which role would you like to see the UK take in the ILC once approved?
Firstly, I would like to see the UK take a strong role in the process of getting the ILC approved. As the first big accelerator conceived as a truly intercontinental project, it presents lots of new challenges. The UK has often seen itself as a potential bridge between Europe and North America, and while this idea has been ridiculed often enough, there is some substance to it. This could be an important piece of the political puzzle in getting an ILC project going. The UK's role in catalyzing the creation of FALC (the Funding Agencies' group) is an example of this.
If and when the ILC is assured, I'd like the UK to make substantial commitments in all areas - design and construction of the accelerator and the detectors, management of the overall project, and of course eventually analysis of the data. I do not think that UK physicists should merely aspire to be users of, or contributors to the ILC; they should be able to regard themselves as co-owners, indeed co-leaders, of the collider and its physics.
Which balance do you expect between the LHC and the ILC in the UK in the coming years?
I think everyone understands that the level of ILC R&D throughout the world has to grow, if it is to successfully lead to a project of this size. That is true of the UK effort too. On the other hand, we certainly want to reap the full physics benefits of our large investment in the LHC - and strong, exciting physics results coming from the LHC will strengthen the case for ILC. There are also exciting new initiatives in other areas, like neutrinos, dark matter and dark energy that we want to pursue. So we have an interesting balancing job ahead of us. We should remember, though, that having a rich menu of excellent physics opportunities is actually a good thing.
Is there anything else you would like to say about the ILC?
It was clear at Snowmass that there's a great deal of enthusiasm right now, and a sense of forward momentum. This is great to see, but we shouldn't let it give us a feeling of having succeeded. Making this project a reality will be hard, and (meaning no disrespect to all the work done so far) we are still only just starting. It will require a lot of focus from all of us on the technical challenges and also on the political ones, not least of which is keeping the bvmachine affordable.