In the last posting I linked to the web-site for next week’s LHC Performance workshop at Chamonix, where the state of efforts to recover from last September’s accident and plans for this year will be discussed. As in many previous cases, linking to an authoritative information source about what is going on at the LHC had the effect of it being quickly shut off to the public. I guess CERN really is serious about the idea that information about problems at the LHC is now only supposed to come from the DG’s office.
So, from now on, I’m sorry to have to do this, but I won’t be linking to any such information sources that people point me to or that I run across. Instead, I’ll try to continue to post here authoritative information that comes my way, without indicating its source. Today, I’ll just note that I’ve heard from an authoritative source about the current informed guesses for when the LHC will be able to start doing physics. The current hope is for first usable collisions at 5 TeV (per beam) in October, with two months for a physics run at that energy before winter shutdown. Peak luminosity would be a few times 1031, integrated luminosity a few tens of pb-1.
Update: CERN does seem to be making an effort to put out more information about the status of the LHC through their press office. Yesterday there was this update posted as “breaking news”, not waiting for the next issue of the weekly bulletin. The news in the update is uniformly good, telling us about how it has been “a good week”. What will be interesting to see in the future is whether less encouraging news makes it out to the public…
Update: The web-page denying access to the Chamonix slides has been changed, it now reads:
This site is temporarily password protected during the duration of the LHC workshop but will be re-opened immediately after the workshop.
I guess that CERN still wants the news of whatever is presented at Chamonix to first come from their press office, but realizes that making available the detailed technical discussion behind this news is a good idea.
5 TeV c.m. energy, or 5 TeV per beam?
5TeV/beam (I’ll clarify that in the text)
This is based upon the assumption that they don’t decide that for safety’s sake they need to run at a lower energy.
I realize that October is a rough estimate but from my experience in technical project management I am guessing this means possibly spring of 2010 (figuring in winter shutdown and unknown delays) before new physics starts happening? So it looks like Fermilab is our best hope this year for the Higgs search and other new physics – is there any news on this front?
mike,
The main news from Fermilab is that the Tevatron is performing extremely well, significantly better than projected, with nearly 6000 pb^{-1} collected already. Even if the LHC does collect some data late this year, it won’t be enough to say anything about a Standard Model Higgs. For the Higgs search, it looks to me as if the Tevatron will be the only game in town for quite a while, with a real possibility of either ruling out or finding the Higgs if it is in the expected mass range, before the LHC has a chance to weigh in.
It’s important to remember that the Tevatron can only say the SM Higgs exists or doesn’t exist at 3 sigma. Impossible for anything more then that.
So, 2 weeks in october at 5 TeV/beam followed by the winter shutdown?
Just to be clear, wasn’t this basically exactly the intended plan for last year, before the accident?
What – safety’s sake in the sense that they don’t want to run the machine above the threshold at which planet-swallowing black holes are created?
No, safety’s sake in the sense not to do further damage to the machine, which would cause further delays.
Coin,
Two months, not two weeks. The hope is to go as late as possible, into December, before the winter shutdown.
Yes, this is pretty much the 2008 plan, the accident has cost them most of a year to deal with
The major issue at CERN nowadays seems to be how little confidence they have in their enterprise. They are doing the same thing with information that Karl Rove et. al. did during the last presidential administration. Filtering all information is the route to spinning information and conveniently forgetting unpleasant truths. What they are doing in effectively prohibiting the dissemination of information is destroying their own credibility. GO FERMILAB!!
Don’t count on 10 TeV center of mass this Fall – they are seriously considering 8 or even 6….
So little attention has been paid to the technical evolution of the LHC. On the good side is the enormous risk that was taken… CERN really has bet the farm on the LHC. Good for them! Amazing amounts of terrific engineering and applied science have been performed.
On the other side… it has been under-resourced. Hard to say that when billions $ have been spent. Still, the amount of money should be compared to the difficulty of the task. A lot of the fun of CERN has been sacrificed to try to make this a successful project… CERN used to have way more variety and a really fun scientific environment for experimental physics. Devotion to one big project kind of squeezes much of the elan out; also, the boundary between team members and outcasts who complain too much gets moved around to fit PR concerns.
Germany has been a bit lukewarm… resources into HERA and Linear Colliders… great to maintain diversity in the program, but many folks knew LHC was the main event, and was hurting.
Experimental physics is hard, really hard, much more challenging than string theory or SUSY. It will be a great success if LHC gets 14 TeV and good luminosity by 2011.
CERN is going the way of Fermilab and Cornell… dreadfully wanting to chase the great physics, but being unable to get the appropriate level of resources for a `Swiss Watch’ startup. They will never give up! But what happens is delays and conversion of operating funds to finish the project. Run 2 at FNAL went through the same thing. Cornell never made a deadline that I can recall.
Does anybody know when Fermilab might have definitive results on a Higgs mass? I know there is a lot of peer-review that has to be completed before the final results are published but perhaps something will leak out by the end of this year?
mike,
Last summer, the Tevatron experiments released an analysis claiming that (using data from both experiments) they could exclude (at 95% confidence level) a Higgs mass in a very narrow range, essentially, exactly 170 GeV. I haven’t heard anything about improvements on this, but they have a lot more data to analyze and are accumulating more all the time. With more data and improvements in the analysis, over the next few years one would expect them to be able to exclude increasingly large ranges of possible Higgs masses (or, see evidence of a Higgs). It appears quite possible that they’ll be ahead of the LHC in this game until at least 2011 or so. Unclear if they’ll be able to go all the way down to 114 GeV, the lower limit set by LEP.
Dear Peter,
I think you perfectly describe the situation at CERN. I must say that I find one of the worst things of last year was the continuous exposure to “Official Press Releases”, which as everybody already knew turned out to be one falser than the other. All of this without the arrogant management ever feeling the need to apologise with the Staff for the release of false and self-contradictory information. I really do hope the new DG manages to change this policy; but this will be a difficult task for him.
P.S. Your blog has been the place where one could find the most updated and complete information about CERN. Thank you.
Nobody,
Thanks, I’m glad this blog has been a useful source of information. I hope that CERN decides to make as much technical discussion of the ongoing LHC project as possible publicly available. Blogs like this one can then provide the service of helping to point people to where to look for such up-to-date information.
Hi,
Did you attend the Grothendieck conference at the IHES? If so, I was wondering if you could write up a summary of what happened. I’m interested to hear what when on.
Thanks.
Anon,
I went out to the IHES for parts of two days of the conference. There was a video-camera there, and I have been hoping the IHES will make available video of the talks, don’t know if they have the capability or intend to. Maybe I will try and write something about the talks that I heard. This history was quite interesting, with Cartier, Deligne, Illusie, Serre and others who worked with Grothendieck during the 60s in attendance. Deligne gave a fascinating talk on motives, which is one thing I’d like to write about, but the topic is quite a challenge, and I haven’t gotten up the energy yet…
Hey,
I actually found a blog that’s covering the Grothendieck conference:
http://homotopical.wordpress.com/
Anon,
Thanks, that’s great. I’ll try to find time soon to put up a posting about this, and maybe add something about motives and Deligne’s talk.
Returning to the topic of the LHC: if there is a new effect, such as TeV-scale gravity, which turns on very rapidly, modulo smearing by parton distributions, perhaps first collecting a lot of data at, say, 8 TeV c.m. energy, before moving up to 14 TeV, might be very helpful for trying to disentangle what is happening.