So, it’s MITs spring break, which gives me a chance to zip over to CERN and see how the CMS tracker checkout is going (my students are heavily involved, and doing excellent work – I’m like a proud poppa!). But I arrived on Easter Sunday, and Friday and Monday were holidays too, so it has been pretty quiet actually. Nothing like arriving in France with no restaurants or stores open for two days! The Europeans take their holidays seriously, about which I am totally hypocritical – on one hand, sometimes it seems that things take infinitely longer due to people taking off all the time, but on the other, I wonder if this isn’t just my work-aholic American upbringing blinding me to the fact that there is more to life than just work, and maybe the Europeans have the right idea. I can argue either side, and frequently do. But, when push comes to shove, what I usually do is think about how much money it costs to run the accelerator – if my piece of the detector isn’t working, that is money down the drain, and we’re talking $100 million per year, or about $10 per second – that’s pretty expensive, so we need to be sure that none of that beam time is wasted. If we can be confident that we’ll get all there is to get out of the beam, all the extra hours and weekend time are worth it. Just don’t tell my wife.
Tags: CMS
I would like to know more about the concerns that physicists have about the LHC and its detectors.
I’ve heard people (not necessarily physicists) wonder if it’s possible for the LHC detectors to give false negatives, or if there might be subtle problems with the collider that could prevent the Higgs mechanism. In other words, they wondered if it was possible for the collider to be (unintentionally) constructed so that it might not see phenomena at higher energies. I don’t know if these concerns are valid, since I don’t think there will be any problems with the collider when it starts up. And personally, I think that if nothing happens at the higher energies, it’s more interesting than if things do happen as expected, which is exciting in a different sense.
PS about cost: $100 million comes from a statement about operating costs when the CERN Director General was arguing that the US should kick in some more for CERN operations. It is certainly a ball park number, meaning it could be off by a bit, and certainly depends on what one does or doesn’t include in the accounting. So that’s not what we’d call a hard number, but just a number I fished out of the web to make the point.
Why the caviat? Well, I can just hear the uproar if a big number like that gets misrepresented. And, it isn’t a really big number like this one.
Hi Sofia
My previous comment had nothing to do with your question, which was “in moderation” when I wrote comment #2.
In a strange way I disagree with you and agree at the same time. I disagree because I do expect to see some hiccups during the turn on of the LHC. The accelerator and detectors are so complicated that something is bound not to work exactly the way we expect – however, we build in a fair amount of redundancy and are pretty good at coming up with solutions to fix these problems as we discover them. But I’ve heard many physicists express the opinion that once the accelerator/detector is built, it will be smooth sailing from there in, and it really isn’t so, at least not in my experience.
That might make you anxious, but not so for me, because of another reason. No matter how the apparatus behaves, we will be able to quantify our sensitivity very well. In plain English, this means we will know what we should be able to see and what we won’t. If our sensitivity is lacking, we will figure out a way to enhance it. If it is sufficient, then as you said, if we can for certain say that we are capable of detecting eg. a Standard Model Higgs and we do not detect one, that would be probably more exciting than actually discovering the Higgs particle. We’ve already studied the phenomenology of the Higgs to death, so if we actually find it, we already know all about it – be more fun if something completely new were found, or if the completely expected turns out to be “not found”, at least for me. The fundamental principles behind the LHC accelerator and detectors are sound, and though there may be devils in the details, I’m certain we’ll be able to exorcise them as we find them. Stay tuned.