The first physics paper using LHC data has appeared this morning on the ArXiv:
http://arxiv.org/abs/0911.5430
Out of 284 events taken on Monday at injection energy (900 GeV center of mass) the ALICE collaboration has pulled a measurement of the particle density around mid-rapidity (the center of the detector, e.g. large angles with respect to the beam). The main detector for this measurement was the silicon pixel detector, with the outer silicon layers and the VZERO detector (a beam-beam counter made out of scintillators on both sides of the interaction region, which can thus determine if a reaction took place in the center of the detector) used as cross-checks. Such measurements were also usually the first ones to come out from the RHIC (the Relativist Heavy Ion Collider at Brookhaven) runs, since they involve only particle counting, and are thus relatively fast to accomplish. Still, it requires good control and understanding of the detector. At RHIC, the silicon tracker of the PHOBOS experiment was usually the first one to provide a measurement.
The results of ALICE are nicely consistent with measurements done at the SppS collider (the CERN SPS, used as a collider for protons and anti-protons, which discovered the W and Z bosons) some 20 years ago. So, it is not “New Physics” yet, but it is an impressive achievement none the less: Just one week after the first collisions, which was not even a real “physics” run, the first paper is out. I’m (almost) speechless… That is definitely a way to spice up breakfast!
Congratulations to ALICE, and the whole LHC crew!
Needless to say, Frank, as I actually work on ALICE, in the very group that wrote and published this paper, I fully intend to blog about this – bear in mind that I am given guidelines about when I am permitted to post about it so you will have to wait until tonight when it is officially accepted.
I actually expected that if you found this out you would wait, since I warned all of the QD bloggers to anticipate a blog from me that was very new and exciting regarding the LHC. But still, the can of worms is open and I am very proud of our achievement – we should be shouting it from the rooftops so I am not complaining!
Sorry to have scooped you, Zoe. From your email yesterday, I was actually expecting something a bit more secret, not the paper on the ArXiv. After all, once the paper is posted there and announced in the mailing (happened over night), it is out in the public, and can (and will be) cited. Thousands of people received the abstract and the link to the full text in an email in time for morning coffee (in the US in time for an after-dinner cocktail), so many will have read it even before me, and discussed it, either in private or in public… And I found it too exciting to keep quiet about, once I saw it was not mentioned in our blog yet…
This is one of the usual paradoxes in big collaborations (I’ve encountered this also more than once): As a member of the collaboration, you might be restricted / forbidden to discuss or use “preliminary” (i.e. not published in a refereed journal) results, while all others can use the result that is posted on the ArXiv.
I am certainly anticipating your in-depth discussion of this first, exciting result from an expert’s point of view!
The reality of competitive physics creates a “race for the state of Grace.” However, professional courtesy and respect should be accorded to those who can rightfully claim responsibility for new developments and attribution for the release of that information. That courtesy is especially applicable when the person’s ability to quickly publish is encumbered by clearances, protocol and policy. Therefore, discretion, really is, the better part of valor. Congratulations to Ms. Matthews and the ALICE team.
RAY OLIVER, ESQ.
RAYOLIVERESQ