Reader Request: LHC

In the Reader Request Thread, Ian asks:

I’d like to hear what you think we’ll learn (if anything!) when the LHC comes online next month.

Well, that sort of depends on the time scale. I’m not a big accelerator guy, but my sense from reading the blogs of people who are is that we’re not likely to learn anything at all this year, other than the answer to the question “do the components of the LHC work?” They’ve got a few weeks of preliminaries before they start any particles going through, and then a whole bunch of sanity checks and calibration tests to do, and a scheduled shut-down in December. It’s unlikely that any actual science will be done in the short term.

As for what they’ll learn in the longer term…

I really don’t have the background to have an educated opinion about what they’ll find when they start getting real collisions. As I understand it, it would be really shocking if they didn’t find the Higgs boson– if the Higgs mass isn’t in the region that the LHC can explore, then something is drastically, devastatingly wrong with the Standard Model.

Beyond that, I don’t have any way to evaluate the claims of different things that might be detected. In a perverse sort of way, I’m actually kind of rooting for “nothing.” As someone outside of high-energy physics, I think it would be kind of amusing if they completely failed to detect any sort of supersymmetric partner particles, or any of the other things that they’re hoping they might see.

It wouldn’t be funny to people in those fields, but as an experimentalist, I enjoy watching theorists squirm.

Actually, the most fun possible result would be for Fermilab to scoop them on the Higgs, and one of the low-energy AMO-based methods to detect something (PNC transitions, a non-zero electron EDM, some departure from theory in the g-factor measurements) that would constrain the range of new physics enough for the LHC results to be anti-climactic. That would be fabulous.

What can I say? I’m a schadenfreude kind of guy…

16 comments

  1. YEAYYYY! You’re a good man, Chad. I’ve always said so. All Hail Chad the Great!

    Seriously, thanks for blogging.

  2. Damned if you do, damned if you don’t: The failure to find anything will be interpretted as a requirement to build an even bigger and more expensive one and find out what went wrong….

  3. You know, it’s not just experimentalists who like to watch theorists squirm… sometimes it’s other theorists. After all, if we figured everything out, then us theorists (I hope it isn’t too conceded to count myself amongst them) would be bored and jobless!

  4. I strongly disagree with #2. The day they build The Next Big Machine and find nothing is the day that higher energy physics comes to an end. The temptation will be to say, “Well, that must be all there is. Figure it out.”

    Theorists may not be out of business if they can redirect attention to the low energy high intensity regime such as AMO, but exactly how do you sell that big collider if the predictions turn out to be useless?

  5. if the Higgs mass isn’t in the region that the LHC can explore, then something is drastically, devastatingly wrong with the Standard Model.

    Maybe not so devastating. It might even be as simple as the nature of the cosmological model that has been wrongly *assumed*:

    http://www.lns.cornell.edu/spr/2006-02/msg0073320.html

    John Conway talked about the absurdity that the modern interpretation of the negative energy states derives in his post to CV:

    http://cosmicvariance.com/2007/11/06/higgs-101/#comment-321311

    John said:

    “The antielectron does not have “anti-mass” in any sense, but looking at the equations you can sort of tilt your head, and if you hold you mouth just right, the antielectron looks like an electron with negative energy moving backward in time. But never mind that.

    Anti-electrons, or positrons, do indeed exist, they move forward in time, and they have positive energy. (Lost yet? Don’t worry…)”

    I talked about this stuff on Dorigo’s blog, as it pertains to Dirac’s Hole Theory and the rationalization of the negative energy states. The missed clue came when Dirac failed to unify GR and QM as he had done with SR and QM, but the mistake was made when they misinterpreted the negative mass solutions that fall out of the Dirac Equation:

    http://dorigo.wordpress.com/2007/10/18/

    It’s really very simple:
    What happens to a finite vacuum when you rip a huge hole in it?

    This is an extremely simple example that you can see was followed by several more relevant posts that went typically unchallenged in the research group:

    http://www.lns.cornell.edu/spr/2005-06/msg0069755.html

    Too bad that theorists won’t “squirm” as long as they can divide by two, because they should have been doing this ever since the smaller colliders failed to find the SM higgs as expected around 160 GeV.

    Luckily for science, there won’t be funding for any more colliders if the LHC turns up nothing.

    THEN sanity in science might actually have a chance.

  6. Unfortunately, if the LHC does not find the Higgs, it will not squeeze theorists into a corner. (Being squeezed into a corner and forced to be clever is the most fun place to be.) The LHC was never guaranteed to find the Higgs; the energy reach just isn’t up to it. That’s what the SSC was supposed to be for. There is a good chance that the LHC will find it, but it’s far from a given, even within reasonable theoretical ranges. It will actually be much easier to find superpartners if they are there than to find the Higgs. (But it will take a long time to be sure they are really superpartners.)

  7. I think you’re quite wrong on that point CCphysicist. If anything, as a condensed matter guy I find this whole business of particle physicists finding what they look for (and seemingly only what they look for) pretty boring. I think some big failures might shake things up and make it fun ;).

    It’s not like anybody in congress who gives them money actually understands anything when they succeed, or will understand anything if they fail, so I think the money will flow (or not) regardless. The predictions are and have been “useless” in terms of the “how to build a better lightbulb” type of thinking for a long time anyways, and that hasn’t stopped high energy people before (and rightfully so I think).

  8. If the LHC doesn’t find the next big thing, you can rest assured there will be a lot of Congressmen asking US lab directors:

    “You mean you paid the French all this money and you’ve got nothing to show for it?”

    The US government is running massive structural deficits and every day another program gets eaten by that wolf. If LHC finds nothing, US high energy physics will end. It might well end even if LHC does find something.

    And condensed-matter types won’t get any of that money. Don’t cheer too hard.

  9. I went on record more than 4 years ago with what is not even the most Sci-Fi prediction for LHC observation. Now that Sean Carroll has upheld the highest traditions of Caltech, I can uphold the lower traditions…

    http://necsi.org/events/iccs/openconf/author/papers/211.doc

    IMAGINARY MASS, FORCE, ACCELERATION, AND MOMENTUM:
    PHYSICAL OR NONPHYSICAL?

    Jonathan Vos Post

    Andrew Carmichael Post

    Christine M. Carmichael
    Physics Department
    Woodbury University
    Burbank, California

    … This paper makes two bold predictions, one of which is experimentally testable by contemporary and near-future equipment, the other of which is more speculative, but may have observable cosmological implications. The detailed derivations of these predictions will presented in subsequent paper, and must be omitted here due to page count constraints.

    The first prediction is that an event of at least 100 GeV might cause the creation of an imaginary mass particle, or “imaginon.” Further, that particle, by gravitational interaction with other particles, will experience imaginary force, and accelerate in a direction orthogonal to normal 4-space, thus disappearing from our observable cosmos (or from our brane). This process would take at least one Planck Time 5.4 × 10^(-44) seconds. How long depends on the speed of the imaginon (real magnitude of imaginary
    velocity vector) and the “brane thickness” of normal 4-space along the 5th (or higher) dimensions. That thickness may well be one Planck Length 1.6 × 10^(-35) meters. Travel of one Planck Length in one Planck Time would mean that the imaginon’s speed is that of light, which is infeasible by Special Relativity for a non-zero imaginary mass. The imaginon thus either travels sub-luminally, the “thickness” of normal 4-space is more than one Planck Length, or the “disappearance” takes longer than one Planck Time. We shall return to the questions of observability of this process.

    The second, hazier prediction, is that an entirely imaginary mass universe exists, with at least 3 spacial dimensions of its own, adjacent and/or orthogonal to normal 4-space. This is what Isaac Asimov has predicted (in the fictional context of Nemesis). However, Professor Asimov neglected to think through the properties of that Imaginary Cosmos.
    In such a cosmos, all particles are of imaginary mass. Hence all pairs of particles have, as previously discussed, antigravitational repulsion from each other. Thus, at first blush, no large cosmological structures would be produced, i.e. no stars, no galaxies, no supergalaxies. However, oppositely charged imaginons can orbit each other in pairs, so long as the electromagnetic attraction exceeds the antigravitational repulsion. Various interactions between imaginon pairs are possible, including Bose-Einstein condensation. Hence imaginary mass universe cosmological structures may be possible after all. The equivalents of fission may be possible (if the Weak Force operates similarly), and fusion (if the Strong Force operates similarly). The imaginary universe would be, in some sense, dual to our 4-space, but neither identical nor opposite in behavior.

    The creation of imaginons may only happen in pairs, for events of at least 200 GeV (or double whatever the minimum energy needed to create a single imaginon). If so, the pairs would be expected to be of equal and opposite charge, thus conserving charge. CPT symmetry would be expected to apply, with similar violations. Such pairs might always be bound, and isolated imaginons not possible, just as isolated quarks are unlikely. Compex-conjugate mass imaginon pairs have a far-field gravitational effect on real mass particles that is asymptotic to zero.

    Specific numerical prediction regarding imaginary mass: as seen from our 4-space, a particle of imaginary mass leaving the brane appears as a violation of conservation of energy and conservation of momentum. That IS allowed by QM, for very small distances and times. By Heisenberg [derivation omitted] we find that the energy needed to kick the imaginon out of the brane is roughly 10-to-the(-8) Joules = a tenth of an erg = 100 GeV This is, not coincidently, the same order of magnitude as the predicted minimum energy of a Higgs boson; was exceeded by the LEP, and will be exceeded by CERN next year (LHC). [Bagger, 2003] Note that NO experiment to date has shown any violation of conservation of momentum. When Pauli proposed the neutrino to explain an apparent violation, Born offered that for subatomic scales, maybe sometimes there could be a violation. As to my suggestion for a super-sensitive Eotvos experiment, see: [Will 1993], [Will, 1998]…

  10. Can’t we always pawn everything on a new particle that has a mass too large to detect now? Hell its worked for 50 years or more!

    If we get a closeup of the “desert” it will be boring, I hope for some new cool physics. Maybe it can be like the 20’s, when Dirac said “first rate physics was done by second rate men”

  11. Man Andew, you must have had alot of bad experience with condensed matter people. I’m in favor of LHC and whatever the next big accelerator is, whether they find what they are looking for with the LHC or not. I just think it would be more interesting if they don’t find what they’re looking for and it leads to some big changes in the theories ;). If anyone in condensed matter wants to steal particle physics money at this point in time they’re crazy.

  12. Professor Otto Rossler compellingly argues that if the Large Hadron Collider creates a micro black hole it may likely destroy Earth…

    And you see this as a bad thing?… 😉

  13. I was hoping someone could help me out with this. I’m not an idiot.

    I’m assured that the LHC can’t possibly hurt anyone because particle collisions in the upper atmosphere occur all the time at energies far higher than the LHC can muster.

    That doesn’t reassure me because the collisions in the upper atmosphere (and presumably every star in the universe) occur between a fast moving particle and a stationary particle while the LHC collisions will occur between two fast moving particles. Are those two occurrences really equatable? If they aren’t really equatable, why am I assured that the LHC can’t hurt anyone? How can you even quantify the risk if Geneva is the only place in the entire universe where two massive particles moving at most of the speed of light are hitting each other?

    Thanks.

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