Have you been paying attention to the LHC? Sure, you’ve been thinking about the scientific results being derived from last year’s data. And you are looking a few months down the road to the upcoming major conferences, now only a little more than two months away, when we might get some interesting news. But right now, the LHC has been running, and running well. Consider this: here is a plot of the integrated luminosity as a function of time for 2011:
And here is the same for 2012:
It is important to note the “preliminary” on this plot — all experiments are working to verify their luminosity calibration. But one can see that the integrated luminosity for this year at the end of April 2012, about an inverse femtobarn is about what it was for last year in the middle of June 2011. In all of 2011, we recorded “only” about five inverse femtobarns. (Dear LHC: could someone produce a plot with the integrated luminosity for both years on the same set of axes? Then I could make this point more easily.) We are recording data at a much faster pace than last year, and that can go straight into the physics bottom line. From what I have heard, the operating conditions of the LHC have been particularly good — the vacuum inside the beam pipe has been better than expected, which means that it will be easier than anticipated to increase the beam currents, and thus to increase the instantaneous luminosity more quickly.
This is important, because we’re about to hit the important big sprint of the year. The LHC has been doing machine studies and a technical stop during the past week. Regular operations for physics will restart around Monday. To be in a position to firmly observe a Higgs boson (if it exists) this year, we need to accumulate 6-7 inverse femtobarns by the “first breakpoint” in late June, under two months away. That is, we will need to accumulate as much data in the next two months as we did in all of last year’s run.
Can the LHC do it? Based on what we’ve seen so far this spring, I think we can try to be optimistic!
