The excitement in the particle physics community is palpable at the moment, with a regular stream of tweets emitting from CERN. In the latest news, the large Hadron collider (LHC) reported that it had reached 1.18TeV with its beams, the highest energy ever recorded for an Earth-bound particle accelerator.

The unexciting news is that we are all still here, and (barring a meteor strike) we will still be here when the LHC reaches 7.5TeV very late next year. In the meantime, what can we expect during the build-up? According to Lynn Evans, the operators of the LHC are taking it very slowly this time, having become a bit paranoid about little things like resistance building in the brazed joints between magnets. One reason for this caution is that not every sector of the LHC was brought back up to room temperature, which means that extra pressure relief valves have not yet been installed on the whole machine yet—that will have to wait until the next maintenance period.

Every sector but the one that failed last time has now been tested at full power, so the operators have some confidence in the machine now, even if they're being cautious about bringing it all together—I can just picture them doing this with long sticks while hiding behind a couch.

In fact, some good has come out of all the wreckage—good is not the right word, but less-bad doesn't roll off the tongue the same way. During the repairs, the detectors were still operating and able to look at cosmic ray events. This has allowed the operators to do a substantial amount of the alignment and calibration work as the LHC was repaired. Now that the beams are circulating again, this will significantly shorten the gap between recording the first collisions and getting the detectors sufficiently calibrated that we can start identifying particles.

The critical question is, when do we get the new physics, guys?

The lowest energy supersymmetric particles are expect to reside in the 1TeV range, which is just barely in the detectable range of the Tevatron and the current LHC operating energy. But, to observe these particles, the LHC would have to stay at that energy for some time—of the order of many months—to generate a statistically significant sample of collisions.

Instead, the plan is to continue to increase the energy until ~3.5TeV is reached. At this energy, it will take considerably less time to generate a statistically significant sample. So, by not taking data now, the LHC staff are really saving themselves some time, as well as widening the net for higher-energy particles.

After a few months operating at 3.5TeV, the LHC's energy will be slowly increased again, stopping at 5TeV (if memory serves me correctly), and finally brought up to 7.5TeV, which is the maximum energy it was designed for.

The big question is the Higgs Boson. The Tevatron has been searching for it, and cosmological observations have also narrowed the search; it is now expected to lie at the upper end of the predicted energy range. As such, it will take the LHC around about a year of data-collecting at full energy to detect the Higgs Boson—if it exists at all, of course.

Exciting times ahead.

Listing image by CERN