Protons Collide At 13 TeV For the First Time At the LHC

An anonymous reader writes to let everyone know the LHC has now smashed protons together at 13 TeV, the highest energy level yet achieved. They've posted the first images captured from the collisions, and explained the testing process as well. Jorg Wenninger of the LHC Operations team says, "When we start to bring the beams into collision at a new energy, they often miss each other. The beams are tiny – only about 20 microns in diameter at 6.5 TeV; more than 10 times smaller than at 450 GeV. So we have to scan around – adjusting the orbit of each beam until collision rates provided by the experiments tell us that they are colliding properly." Spokesperson Tiziano Camporesi adds, "The collisions at 13 TeV will allow us to further test all improvements that have been made to the trigger and reconstruction systems, and check the synchronisation of all the components of our detector."

Comments

Re:The begining

[Anonymous Coward]

At the moment the big thing in particle physics is attempts to try to figure out what dark matter is. Even if the LHC does not detect any dark matter particles, that would in itself constrain the possibilities significantly, and there are other experiments currently in teh works, and active, trying to detect it in various ways. Also, even if the LHC only find that the standard model works the way it is expected to, that would in itself eliminate a great deal of theoretical possibilities, which would give scientists a better idea for how to proceed in the future.

With regards to future experiments, the LHC really pushes the limit of what is practical in accelerator technology. If you want to build something bigger you start getting into problems with the Earth's curvature and seismic activity. There is a lot of research into alternative ways to accelerate particles, such as plasma Wakefield accelerators, but while they do show big improvements in the energy attainable, current technology does not allow them to be used to generate a high quality particle beam, as is necessary for high energy experiments.

Sad as it is to admit. It is unlikely that we will be able to go much higher in terms of raw energy in the foreseeable future. Future physicists will have to find alternative means of studying fundamental particle interactions, possibly through indirect methods, as it simply is not very practical to increase the energy in collisions indefinitely.

Re:The begining

[Anonymous Coward]

The particle is something that very much resembles a minimal Standard Model Higgs, to the point of being presently indistinguishable from any other proposed Higgs model. At 14TeV and with increased luminosity it's hoped that various proposed splittings will become visible in the data, ruling many possible alternate theories out (or in!).

What we're really expecting to see is the first direct proof of beyond-the-standard-model physics. There are corrections to various physics processes going on whose contributions to observable quantities, if you only plug in known particles/interactions, basically increase without bound at higher energies (these are the "radiative corrections" we hear about). At much past 1-2 TeV/parton (or 6-12TeV/proton), the resulting quantities and cross sections predicted go looney tunes (specifically, weak interactions violate unitarity and we end up with probabilities larger than 1 - oh teh noez!).

It's considered almost guaranteed that we must see *something* outside of the standard model at these energies, because the standard model blows up but physics, of course, does not.

SSC?

[Michael Woodhams]

The Superconducting Super Collider would, if not cancelled, have had 40TeV collisions about 15-20 years ago. The LHC is using computing resources that are very challenging to supply in 2015, exceeding what would have been achievable for SSC by a factor of perhaps 1000 (15-20 years of Moore's Law.)

Had SSC been completed, would the computing and detector technology have been able to make effective use of the collisions? Was it in fact a correct decision to abandon it at that time? Would the much higher collision energy have reduced the detection/computational load in some way? (E.g. higher signal to noise, leading to needing many fewer collisions.)