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:Results

[ganjadude]

well this was actually a calibration not a "test". From my understanding to make sure no stray particles are going "off track" they ran this test. So while it is the first time its been run to full power, it wasnt for any reason other than calibration. Now, I dont know if they are collecting and running any data on the collisions that did happen

Re:Results

[Megahard]

Here's a video

http://www.cyriak.co.uk/lhc/lh...

The begining

[coastwalker]

IANA theoretical physicist but...

In six months or so we will know whether there is anything absolutely extraordinary to be learned from the LHC. It is only a hope that new physics will be found at 13TeV. We spent the money to find the Higgs and found it, in the next year or so we will know a lot more about it but the hope is that something of interest to the general public may come out of the energy boost. I would not hold your breath though, so far we have only seen exactly what we expected to see. The next big thing may be to search for the gravitational waves from the big bang to settle the question of whether inflation started the universe. No one is funding it until at least 2035.

Sadly I really think we need to keep our fingers crossed that a mere doubling of energy in the LHC will find anything startling.

Unfortunately we probably need to spend at least as much money on a different experiment to find another amazing thing.

Having said that it is already a triumph to have discovered the Higgs scalar field - something that was only a theory until the LHC came along and now it is in the text books because of it.

You may find that like the moon landing, a tremendous leap forward is followed by 50 years of disappointment once the political will has died. (At least we have transparent aluminum AlN now) :-)

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.)

Re:SSC?

[Anonymous Coward]

The true excellence in the LHC is not its maximum collision energy alone (which of course is awesome in itself), but the luminosity and resolution that is included with it. The reactions that are hunted occur at miniscule rates, and the major effect of the LHC is the big step up in several orders of magnitude as the pure number of collisions go. The design figures quoted for the SSC luminosity were only an order of magnitude lower than corresponding figures for the LHC, but that is not to be taken lightly.

Regarding energy resolution, the SSC would probably due to its time have been comparable to Tevatron, which is a factor 5 worse than the LHC. In practice this accounts to a large disadvantage for particle detection, which could qualitatively be mulitplied by the difference in luminosity, leaving the SSC at a disadvantage of about a factor 50 in resolving new particles, though compensated to some degree by its higher maximum energy. In a way, this might mean that it would have been more difficult to discover the Higgs with SSC, but that it would had greater potential in finding physics "beyond the standard model". The latter statement is extremely speculative, though, since the LHC has not even been running near its maximum capacity yet.

Also, the intended much larger jump in maximum energies as compared to available technology at the time might very well have led to SSC becoming a giant money-eating hole, which is one of the very reasons it got cancelled. It would be easy (for a certain definition of "easy") to draw up blueprints for a machine 10 times more powerful than the LHC -- but you would need to be a right-out magician to make it realizable due to monetary constraints. The LHC was successful in this regard, much since it could draw on the lowered price of technology over time as compared to SSC, which is another fantastic achievement by the design team. The re-use of the tunnels saved an enormous amount of construction funding, which could instead be channeled towards more interesting technology advancements.

Projects such as the SSC, Clic, ILC, etc., are greatly useful in their own right, even though they might not end up in realizable machines. The ideas and experiences from the design phase permeate to upcoming projects. As an example, the "Super" in SSC meant the use of superconducting magnets, which is a basis of the LHC construction.

The lack of computing resources at the time would also have been a major blocker for SSC, as you mention. In the design of the SSC, it in hindsight seems like they designed it without real regard for the needed monetary investments, or at least as if they expected several orders of magnitude larger funds than reasonably were to be expected. Perhaps the design process started in a different climate, and they expected "blue skies" scientific budgets to continue to rise so that they would meet their requirements when the design phase was done, when the actual development turned out to be the opposite.