Wednesday, September 01, 2010

Committee: run Tevatron through 2014

Physics World has brought us some fresh news about the Tevatron's future:
Three-year extension recommended for Tevatron
Fermilab's Physics Advisory Committee (PAC), supported by Lisa Randall, will release a letter today. It will recommend to continue the Tevatron activities until 2014 in order to find the Higgs boson or at least more information about it.




I understand all kinds of reasons why it would be a good idea for the Tevatron to continue. American particle physicists don't want to watch a relative demise of their place in the discipline. They don't want to lose their skills and speed - and jobs. And the collider works very well, indeed.

But if I rate the relative advantage of an operational Tevatron and an operational LHC, I guess that the Tevatron will be seen to be an obsolete gadget as soon as in 2011. Slightly higher instant luminosities won't be enough to beat the LHC's huge energetic advantage. And the latter can speed up certain (or most) discoveries (and the falsification of invalid hypotheses) above 100 GeV by a factor of 100,000 even when the luminosities are the same: see e.g. Alves, Izaguirre, Wacker 2010.

When the LHC accumulates 0.05/fb of data - and it already has collected about 10% of this amount - if will surpass the Tevatron with its 10/fb in the search for SUSY: check Jon Butterworth in the Guardian.

Also, people seem to use an incorrect argument about the Tevatron's integrated luminosity. It's much higher than the LHC's integrated luminosity, of course. But this is not an achievement of the Tevatron's operations between 2010 and 2014: it is an achievement of the Tevatron's work until 2010. ;-)

In principle, most of the acquired Tevatron data can be combined with the LHC data, too. The relevant quantity that should be compared if you decide which colliders should be running is the instant luminosity and energy - not the integrated luminosity. With this comparison, I am convinced that the Tevatron's operations will be seen as redundant ones in less than a year.

4 comments:

  1. Seems like a serious failure of leadership and of imagination.
    This situation has been a long time in coming. Other institutions in the same circumstances retooled their instruments and their research focus before becoming palpably obsolete. The Tevatron has not, so it is now facing death.

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  3. One reason to keep Tevatron going is the same reason political parties run candidates in seemingly safe seats. You never know when the competition will suffer an epic fail that will make you the best available one in contention.

    Given technical issues already delayed LHC, it would hardly be surprising is something else happened there that put it out of commission for an extended period of time. These are fussy machines and there are a nearly infinite number of ways for them to unexpectedly break for a prolonged period of time.

    Also, if LHC did break, the sovereign debt crisis in Greece, which threatens to spread, could make it hard to raise funds to repair it if they are far beyond what was budgeted in a timely manner. The reason that the next big thing is there instead of in the U.S. was due to a similar fiscal shortfall combined with lack of political will.

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  4. Dear Andrew, that's fun but first: you hugely overestimate the extent of "competition" in these science projects.

    There is and there should be some competition and there are some separate budgets and selective pride, but at the end, all of them are collaborators in physics. Moreover, a sizable fraction of the LHC staff has been or is Tevatron staff, too.

    Look at Tommaso Dorigo. It's not an exception. A much bigger fraction than the people who are in the GOP and the Democrat Party at the same moment.

    Moreover, the U.S. has sent funding for the LHC, too - something comparable to 5-10 percent which obviously beats most of the European member countries.

    Even if the LHC exploded, you wouldn't really save much by the Tevatron simply because it can't replace the LHC's energy. My opinion that it's not too useful to run the Tevatron for too long is not just that it is weaker than the LHC - it is also that even without comparisons, its reach is limited. It may be better to save the money for a bigger project in the future. The Tevatron has run for many years and many long years are needed just to "slightly" increase what it has already told us. The insights per bucks are decreasing.

    Also, I think that in science, one should never excessively "insure" all the projects. Science is always a risky business for its own fate and it should be. No one can ever promise you that you will make a discovery with a gadget you paid. On the other hand, a failure of pure science experiment poses no risk whatsoever to the societies. So the societies don't have to insure themselves against anything.

    And when it comes to the safety of the potent research itself, it should be decided purely on costs-and-benefits basis (where the benefits are scientific insights), without any additional bias for the "precautionary principle" and similar mumbo jumbo methods to distort all the numbers arbitrarily.

    The fact is that the epic fail of the LHC is unlikely, and it makes no sense to insure physics against this scenario by running a whole second collider, especially because even in the case of an epic fail, the Tevatron wouldn't save much.

    Concerning the redundancy, there *is* a lot of redundancy everywhere. The Tevatron has two big separate detectors and teams, D0 and CDF, and so does the LHC, ATLAS and CMS. Redundancy does exist everywhere. But how much redundancy is a good thing? I surely don't think that the more redundancy one has, the better.

    At any rate, this is an Academic discussion because the running of the colliders is determined by politics, not by careful judgements, and I think that the Tevatron will continue to run.

    Best wishes
    Lubos

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