Latest From the LHC

Things seems to have been going well at the LHC recently, with the current schedule expecting injection of beams in a little more than two months from now, on Thursday November 19. After that, the plan is for a week and a half of beam commissioning at 450 GeV, and 450 GeV collisions at the beginning of December. The machine will then be ramped up to first 1 TeV, then 3.5 TeV, with 3.5 TeV collisions on December 14.

Soon after that (December 17), the machine will go into a technical stop period for the holidays, starting back up January 7. From then on, the plan is for a month of more commissioning work and pilot physics. The first regular physics run at 3.5 TeV will last about 3 months, with expected luminosity of 54 pb-1. Then in May, the energy will be increased to somewhere in the range of 4-5 TeV, with a run beginning in June at that energy lasting until mid-October, with expected luminosity of 274 pb-1. The machine will then be reconfigured for a one-month run with heavy ions, and then go into a long shutdown at the end of November.

Anyway, that’s the latest plan, reality may turn out differently. For up to the minute information on how things are going, you can follow along here. The last sector to be ready is now supposed to be sector 67, which is in cooldown, the magnets currently around 200K.

See here for a recent Science Magazine story on the subject from Adrian Cho.

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9 Responses to Latest From the LHC

  1. dan says:

    “and then go into a long shutdown at the end of November.”

    What is the benefit of a long shutdown?

  2. Peter Woit says:

    dan,

    A lot of work on the machine may be needed in order to get it to run not at 3.5-5 TeV/beam, but at the design energy of 7 TeV/beam. This may, for instance, require warming up and then cooling down the entire ring, which would be a time-consuming process.

  3. neo says:

    How did they fix all those badly soldered connections?

  4. dan says:

    ok, if everything goes according to schedule, when will data from LHC start pouring in? Presumably the Tevatron will continue to hunt for Higgs/sparticles

  5. Peter Woit says:

    dan,

    Well, the schedule has enough data to be interesting coming in during 2010, but not enough to really compete with the Tevatron on the Higgs. Tommaso Dorigo has a relevant posting about this

    http://www.scientificblogging.com/quantum_diaries_survivor/worst_nightmare_scenario_cern_150_gev_higgs

  6. dan says:

    Thanks,

    “f superpartners don’t show up at 7 TeV/beam”

    What year at the earliest if everything goes to schedule would the LHC collect enough data from 7 TeV collusions due to luminosity to be able to show or suggest sparticles or rule it out?

  7. Peter Woit says:

    dan,

    Since we don’t the masses of superpartners, there’s no answer to your question. Depending on different choices of the masses, you can come up with cases where the LHC should see something quickly, or not for a very long time, if ever.

  8. dan says:

    Hi,

    I am well aware that SUSY could be broken at any scale.
    I was thinking if MSSM or next to MSSM Distler seems to promote, and if SS is the correct explanation for EW stabilization. What range of mass would rule out SS as the explanation for higgs hierarchy-EW based on LHC energy and luminosities?

  9. Peter Woit says:

    dan,

    As far as I know, you can push all the superpartner masses high enough to be invisible at the LHC, at the cost of requiring higher amounts of fine-tuning to explain the hierarchy problem. So, depends what degree of fine-tuning you are willing to accept.

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