A Path Forward

A much anticipated report on a future path for particle physics was released last week. It has provoked a storm of attention in the press. It’s written by a panel of wise experts and the Chair is making the rounds presenting it, and will be at SLAC tomorrow (Friday) morning. We are expecting a full house.

This report could be one of the most important events to happen in high energy physics in the last decade. It has the potential to have tremendous influence on how our field evolves and to ensure that the US retains a strong program. It is worthy of much thought and discussion. And, of course, another post on this blog! Clifford and others reported the breaking news last week, and now we’ve all had the time to actually read the full 140 pages of the report and think about what it says. I’ve also since heard two presentations from two panel members, and there is more to be learned from just reading alone. So here is yet another synopsis:

Caveats: First, I must make some confessions. (1) I gave input to the panel. I was asked to present the physics case for the International Linear Collider (ILC) to the panel. In fact, I was the only speaker they heard which outlined the actual measurements that the ILC could perform. (I wasn’t nervous while giving the talk or anything…) I also served on a panel which wrote a report for the panel outlining the role of the ILC in the era of the Large Hadron Collider (LHC). That report was a lot of work, but we are pleased with how it turned out. A snazzier version will make its public debut next week, and CV fans will be the first to read all about it. I also served on an ad-hoc committee to address a set of questions posed by the panel. CV readers even helped on that one!
(2) I am tickled pink with this report! I very strongly support the International Linear Collider. I believe that it will be necessary to decipher what is found at the LHC – it also has the potential to directly study dark matter particles in a controlled laboratory environment. In addition, I would like to see the US host the ILC because I care deeply about the vitality of the US high energy physics program in particular, and the US science program as a whole.

Some Background: Particle physics is in crisis in the US. Our accelerators and experiments are being shut down, one by one, with no new particle science to take their place. Our budget has been stagnant for over a decade and we can’t afford to start any new experiments. In the long term, we never recovered (in many ways, actually) from the cancellation of the Superconducting SuperCollider. Meanwhile, Europe is pouring money into the field spending twice as much, in actual dollars, as the US; Japan alone invests half as much as the US; and China, Korea, and India are all starting new initiatives. It is obvious that we are losing our competitiveness and yes, there are concrete examples (e.g., the late start-up of one of our neutrino experiments MINOS, and the lack of ability to develop our detector technology for the ILC.)

Should we care? That’s the question. Us particle physicists have been pressing for more support for years. We strongly believe that our science is exciting and is fundamental to the health of the US physical science program as a whole. We have argued the case over and over. And that’s the point – arguing for your own survival, while necessary, appears self-serving. Not to mention the current national environment where if you don’t put a new gadget into the average Joe/JoAnne’s hands every week you are considered useless.

So, the National Research Council of the National Academy of the Sciences decided to step in. Their Board on Physics and Astronomy formed a panel to (1) Identify, articulate, and prioritize the scientific questions and opportunities that define elementary-particle physics, and (2) Recommend a 15-year implementation plan with realistic, ordered priorities to realize these opportunities.

So far, this sounds like every other panel formed over the last decades. Except for one major difference: the Academies appointed a diverse and very high level membership to the panel. Very distinctive people (heavy-hitters if you like), far outside the world of high energy physics, served on this panel. This was a highly unusual composition for such a committee. Reading between the lines, one could think of this as a test for US particle physics – is it worth saving or not? High risk for us.

Panel Members: The panel was chaired by Harold Shapiro, President Emeritus and Professor of Economics at Princeton University. Sally Dawson, physics department chair and particle theorist at Brookhaven National Lab was vice-chair. Half of the panel consisted of high energy theorists and experimenters, including two Nobel prize winners (David Gross and Jerome Friedman) one European and one Asian physicist. The other half were scientists from other fields and non-scientists. These included eminent astrophysicists and astronomers, prominent condensed matter physicists, accelerator physicists, biologists, and experts in public policy (particularly science policy) such as former presidential science advisor (Neal Lane), the former CEO of Lockheed-Martin (Norman Augustine), the head of the Memorial Sloan-Kettering Cancer Center and Nobel prize winner(Harold Varmus), and the head of the EOP Group (Joseph Hezir). You know these people are important – they have their own wiki pages!

These are all very busy people, who took a year out of their lives to learn about particle physics! Most importantly, they are leaders – experienced, skeptical, and strong-willed individuals. One simply does not pull the wool over their eyes – they immediately spot a hole in an argument and zero in on it. I can personally vouch for the fact that their questions were tough, and even hostile at times. They were not necessarily favorably pre-disposed towards particle physics.

The Process: The panel met 6 times in the US, 3 times in Washington DC, once each at SLAC, Fermilab, and Cornell. In addition, they took field trips to visit the major foreign national high energy physics laboratories CERN, DESY, and KEK. At each meeting, members of our community were asked to give presentations and were grilled afterwards (all open to the public). There was opportunity for open (non-solicited) presentations from the community, and panel requested community input in the form of letters. Everybody had the opportunity to give input to this panel. All of the input is collected on the panel’s website.

Single Most Important Conclusion: Particle physics passed the test. YES! The panel concluded:

Simply stated, given the excitement of the scientific opportunities in particle physics, and in keeping with the nation’s broader commitment to research in the physical sciences, the committee believes that the US should continue to support a competitive program in this key scientific field.

Particle physics plays an essential role in the broader enterprise of the physical sciences. It inspires US students, attracts talent from around the world, and drives critical intellectual and technological advances in other fields.

The field of particle physics is entering an era of unprecedented potential.

The results of the committee’s analysis have led to its chief recommendation. The United States should remain globally competitive in elementary particle physics by playing a leading role in the worldwide effort to aggressively study Terascale physics.

It didn’t have to turn out this way – the panel could have concluded otherwise. High risk. High pay-off.

Panel Recommendations: Here are the recommendations, listed in order of priority, with some paraphrasing on my part for brevity.

Fully exploit the physics opportunities at the LHC.

Adopt an aggressive approach for the realization of the ILC. The US should launch a major program of R&D, industrialization, and management studies for the ILC.

The US should announce its strong intent to host the ILC and perform the work necessary to produce a compelling bid. The panel can’t endorse immediate decision on the ILC in the US due to uncertainties in cost and possible LHC discoveries. However, we should make it so that 5 years from now the US will be the premiere site for the ILC, if at the time we choose to build it.

The connection between high energy physics and astrophysics and cosmology should be strengthened. An understanding of high energy physics is needed to interpret astrophysical data. Such scientific opportunities and priorities should be coordinated jointly by the NSF, DOE, and NASA, with an increased level of funding from traditional particle physics sources.

A neutrino program should be determined through a well-coordinated staged effort developed with international planning and cooperation, avoiding duplication.

US participation in large-scale precision physics should continue, but at a level sustainable within the overall particle physics budget. Participation in small-scale precision studies should be encouraged.

Some Comments:

In listening to the presentations the past week, it is clear that the panel worked very hard to arrive at this list of recomendations. It is their conclusion that hosting the ILC is the best path forward to maintaining vitality and strength to the US particle physics program and hence US physical sciences program as a whole. They believe that a major investment at this time in a large-scale accelerator-based neutrino or flavor physics program would significantly shrink and weaken the field.

Also, when the report talks about US leadership in particle physics, what is meant is that the US should be a leader. Not the leader, but one of the leaders in the world. They are very careful to emphasize this point!

Interestingly enough, these are essentially the same set of recommendations as those contained in a 2001 report from a panel solely constructed of high energy physicists.

In his announcement of the report, Shapiro was asked if the US can afford to spend so much money on basic science in a time of tight budgets. His reply was (recall he is an economist):

the US’s economic vitality isn’t won in a day, but in a generation. It will wither away if we only pick the fruits off the tree planted in the last generation and don’t nourish the tree that will feed the next generation.

What’s Next: The particle physics community needs to decide whether it will rally around this report or not. I feel strongly that it should. This is a golden opportunity that numerous people have worked hard for, and we should take every advantage of it. It won’t happen again.

Yes, going for the ILC is a huge risk, and the strategy may not work. But the reward would be tremendous. Looking at our other options, and thinking of the science we would miss out on, in my humble opinion, how can we not take the chance? The trick, however, is to invest in the ILC without killing off everything else – that’s for another committee to figure out! High risk, high pay-off.