Quite in advance with respect to the stated goals of its 2010 collider program, the Large Hadron Collider has produced yesterday night the instantaneous luminosity of 10^32 cm^-2 s^-1 in the core of the ATLAS and CMS detectors. This is great news for all of us: at such a collision rate, on average one top quark pair is produced every minute, and one 120 GeV Higgs boson (if the thing exists) every 10 minutes makes its apparition there! (Calculations are in this recent post).
The figure on the right shows the progress of data accumulation by the CMS detector. THe progress of data collection is striking; the last run allowed the experiments to collect about two inverse picobarns alone, in about ten hours.
The progress of the LHC is remarkable, especially since the machinists have managed to obtain the 10^32 luminosity goal they had set for 2010 running with quite some advance, and with 40% fewer protons. I foresee that by the end of the year the LHC personal record will double, reaching half the top luminosity reached by the LHC's competitor, the Tevatron collider.
Now it would not be fair to compare the luminosity of the two machines without some qualification: the Tevatron collides protons against antiprotons, and antiprotons are quite hard to produce -it takes a hundred thousand proton-target interactions to select a single antiproton! On the other hand, the Tevatron has ran for 25 years, and the tuning of particle beams is an excruciatingly long and complicated process; LHC is still in its infancy, although it already competes with old uncle Tevatron.
I have to say that the speed at which data are being delivered to the experiments by the CERN accelerator is not the only factor which is surprising me these days. I am seeing results coming out of ATLAS and CMS at a pace quite unheard-of. I was accustomed to Tevatron standards, where after data are collected the processing by software algorithms and the delivery of calibrated, distilled reconstructed information for experimental analysis had a typical turnaround of a few months. At the LHC you take data one night, and on the next morning your graduate students deliver you analysis results as fast as the newspaper boy. This makes things all the more exciting.
So it shows that although LHC started much later than scheduled a few years ago, experimentalists have not been sitting still: refined software algorithms have been crafted, and all these need in order to run, do the number-crunching, and producing new information is a feed of terabytes of digitized data from the detectors. These are exciting times to be an experimental particle physicist!
LHC Breaks Into 10^32 Territory!
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