Cern LHC sees high-energy success

[wautd]

Quicker than expected

Europe's Large Hadron Collider (LHC) has produced record-breaking high-energy particle collisions.

Scientists working on the European machine have smashed beams of protons together at energies that are 3.5 times higher than previously achieved.

Tuesday's milestone marks the beginning of work that could lead to the discovery of fundamental new physics.

There was cheering and applause in the LHC control room as the first collisions were confirmed.

These seven-trillion-electronvolt (TeV) collisions have initiated 18-24 months of intensive investigations at the LHC.

Scientists hope the studies will bring novel insights into the nature of the cosmos and how it came into being.

Many of them have described Tuesday's event as the beginning of a "new era in science".

But researchers caution that the data gathered from the sub-atomic impacts will take time to evaluate, and the public should not expect immediate results.

"Major discoveries will happen only when we are able to collect billions of events and identify among them the very rare events that could present a new state of matter or new particles," said Guido Tonelli, a spokesman for the CMS detector at the LHC.

"This is not going to happen tomorrow. It will require months and years of patient work," he told BBC News.

The LHC is one of the biggest scientific endeavours ever undertaken.

Housed at Cern (the European Organization for Nuclear research) in a 27km-long tunnel under the Franco-Swiss border near Geneva, the LHC successfully collided particle beams travelling at close to the speed of light.

The expectation is that previously unseen phenomena will reveal themselves in the resulting debris.

A key objective is to find the much talked-about Higgs boson particle.

This is thought to have a profound role in the structure of the Universe, and would enable scientists to explain why matter has mass - something which, at a fundamental level, they have difficulty doing at present.

The LHC broke down shortly after its opening in 2008 but, since coming back online late last year, has gradually been ramping up operations.

Two proton particle beams have been circling in opposite directions in the magnet-lined tunnels at 3.5 TeV since 19 March.

Having established their stability, these beams were allowed to cross paths and collide.

This 7 TeV event, which took place on Tuesday at 1200 BST, was the highest energy yet achieved in a particle accelerator.

The LHC's four major experiments - its giant detectors Alice, Atlas, CMS and LHCb - have now begun to gather their first physics data from the collisions, a development that Cern described as an "historic moment".

"This is new territory," said Professor Tonelli.

"If you want to discover new particles, you have to produce them; and these new particles are massive. To produce them, you need higher energies. For the first time [on Tuesday], we will be producing particles that have energy 3.5 times higher than the maximum energy achieved so far.

"This is why we can start the long journey to make major discoveries in identifying a new massive state of matter."

At the end of the 7 TeV (3.5 TeV per beam) experimental period, the LHC will be shut down for maintenance for up to a year. When it re-opens, it will attempt to create 14 TeV events.

[adam_grif]

http://www.hasthelargehadroncolliderdes ... ldyet.com/

Seems like we're safe so far.

Also, it's nice to see the thing getting some action finally. I remember anticipating it getting fired up, then getting totally shattered when it broke.

[Admiral Valdemar]

It's still "broke", but that's an issue to be rectified next year and will take a while to deal with since a project this big and costly is its own prototype. Nice to see we're getting something out of it finally.

[Kanastrous]

I know that the really important thing is that the research gets done, wherever it gets done, but it just kills me that this project isn't US-based, that this country isn't where the world's top people want to come to use the gear. Yeah, stupid nationalistic pride, I know. But I can't help wishing that we were where the action was at...I'd rather have supercollider bragging rights, than stealth bomber bragging rights...

[Akhlut]

I know that the really important thing is that the research gets done, wherever it gets done, but it just kills me that this project isn't US-based, that this country isn't where the world's top people want to come to use the gear. Yeah, stupid nationalistic pride, I know. But I can't help wishing that we were where the action was at...I'd rather have supercollider bragging rights, than stealth bomber bragging rights...

Oh, but we could have! We were going to make the Superconducting Super Collider in Texas, and then a bunch of Congressmen got all pissy and cut funding, leading to the most expensive hole ever dug!

[Kanastrous]

Well, I guess they underwrite their stupid nationalism differently than I do.

[Gil Hamilton]

I know that the really important thing is that the research gets done, wherever it gets done, but it just kills me that this project isn't US-based, that this country isn't where the world's top people want to come to use the gear. Yeah, stupid nationalistic pride, I know. But I can't help wishing that we were where the action was at...I'd rather have supercollider bragging rights, than stealth bomber bragging rights...

CERN is hosted in Geneva, but its an international lab. There are physicists from all over working there, including the United States. These sorts of things always are international efforts. LHC combines brilliant minds from all over, with Switzerland's hosting, and cheap French electricity powering it all. I don't see why that should kill you that the hole in the ground is on the Swiss border rather than the United States.

[Fingolfin_Noldor]

Well, it will take 1-2 years to analyse the tera to petabytes of data across all the data centers across the world. So hold your breath...

[Kanastrous]

I know that the really important thing is that the research gets done, wherever it gets done, but it just kills me that this project isn't US-based, that this country isn't where the world's top people want to come to use the gear. Yeah, stupid nationalistic pride, I know. But I can't help wishing that we were where the action was at...I'd rather have supercollider bragging rights, than stealth bomber bragging rights...

CERN is hosted in Geneva, but its an international lab. There are physicists from all over working there, including the United States. These sorts of things always are international efforts. LHC combines brilliant minds from all over, with Switzerland's hosting, and cheap French electricity powering it all. I don't see why that should kill you that the hole in the ground is on the Swiss border rather than the United States.

Like I said, stupid nationalistic sentiment. Yes, I'm well aware that these projects are international in character; Fermilab hosts people from all over the world, too. If there's a big magnificent cutting-edge international prestige project that everyone in the field wants to get in on, there's something nice about it being hosted by your own nation. I'm not taking anything away from the Swiss and French achievements, by admitting that I envy them.

[Knife]

Does anyone want to break down what happened at CERN into lay english? They smashed sub atomic particles together and made a shit ton of energy and it shows? They are looking for?

Edit: on the news this morning they were blathering about the 'god particle'. Wha?

[Kanastrous]

IIRC 'The God Particle' is Leon Lederman's tag for the Higgs Boson. He popularized the term in his high-energy-physics-for-laypersons book by the same title. I think I read somewhere that he now regrets having coined the term...

Since I only understand any of this stuff in lay English I guess I'll try: given theoretical particles can only be (theoretically) produced at certain energy levels: the closer you want to get to the state of matter/energy at the Big Bang, the higher an energy investment you have to make, in disassociating typical matter into those primordial constituents. So the theorists make their predictions as to how massive the sought particles would be, and at what energy threshold you would see them appear, and - since I don't think any of this can be directly observed - you also need to know what decay particles to look for out of a given type of collision, in order to tell whether or not the particle you seek was created within the collision area, or not.

The tasty payoff from demonstrating the existence of the Higgs Boson (or other particles) is that it validates the model constructed by the theoreticians - or doesn't validate the model, in which case I guess you either keep running the experiment, devise new ones, or just clout the theoreticians back to their blackboards...

[SCRawl]

Does anyone want to break down what happened at CERN into lay english? They smashed sub atomic particles together and made a shit ton of energy and it shows? They are looking for?

I'll give it a shot.

The big headline is that the energy of these collisions is unprecedented. The more energetic these particle collisions, the greater the likelihood of something previously unseen becoming detectable from them. For example, if they're trying to tease a Top quark -- the one with the highest rest mass, IIRC -- to come out and be detected, then you have to put at least that amount of rest mass worth of energy into the collision.

Figuring out what actually happened during those collisions that were recently announced will take lots of computing power, and therefore lots of time. That's why they didn't announce any results other than that they were able to get the thing powered up properly.

Edit: on the news this morning they were blathering about the 'god particle'. Wha?

That would be the Higgs Boson, whose theoretical existence they are, among other things, trying to turn into experimentally verified existence.

[Kanastrous]

sorry SCRawl - I was editing while you posted, didn't mean to step on your post there.

[Serafina]

Basically, the Higgs-boson is suspected to be responsible for matter having mass.
Just forget about the term "god-particle", that's just a media buzzword.

[SCRawl]

sorry SCRawl - I was editing while you posted, didn't mean to step on your post there.

Not at all. More explanations are better than fewer.

You know, I remember when the SCSC was still a under construction, when I was an undergrad physics student in the early 1990s, and still had thoughts of pursuing it as a career (i.e. before I realized that I wasn't very good at physics). I was thinking at the time that it would just be a few more years before I could read to the end of the mystery novel, so to speak, and find out if the stuff I was learning in my particle physics class was actually true (insofar as experimental verification can reveal the truth). Turns out I had to wait a little more than that...

[Simon_Jester]

IIRC 'The God Particle' is Leon Lederman's tag for the Higgs Boson. He popularized the term in his high-energy-physics-for-laypersons book by the same title. I think I read somewhere that he now regrets having coined the term...

Since I only understand any of this stuff in lay English I guess I'll try: given theoretical particles can only be (theoretically) produced at certain energy levels: the closer you want to get to the state of matter/energy at the Big Bang, the higher an energy investment you have to make, in disassociating typical matter into those primordial constituents. So the theorists make their predictions as to how massive the sought particles would be, and at what energy threshold you would see them appear, and - since I don't think any of this can be directly observed - you also need to know what decay particles to look for out of a given type of collision, in order to tell whether or not the particle you seek was created within the collision area, or not.

The tasty payoff from demonstrating the existence of the Higgs Boson (or other particles) is that it validates the model constructed by the theoreticians - or doesn't validate the model, in which case I guess you either keep running the experiment, devise new ones, or just clout the theoreticians back to their blackboards...

You got it.

There are at least two things we're looking for from the LHC that I can think of off the top of my head. One is the Higgs boson, which is one of the last remaining unobserved items predicted by the Standard Model that unified (most of) 20th-century physics. Again, it's the one that "explains mass." We've done experiments looking for it at Fermilab's Tevatron and in the LEP (CERN's giant electron-positron collider; they ripped it out back in the '90s so they could build the more energetic LHC in the same tunnel). The results basically prove "the Higgs is too massive for us to create on demand," because they can't achieve the collision energies they need to spawn the things reliably.

We've done other experiments measuring physical constants that prove that if the vanilla Standard Model is correct, then there are sharp upper bounds on how massive the Higgs can be, because if it were really really massive it would have observable effects that we don't see. So if the vanilla Standard Model is right, and given the negative/inconclusive results at Fermilab, then the Higgs must have a mass between about 110 and 180 GeV*. With the LHC, even at relatively modest beam energies (by LHC standards), we can easily generate the kind of collision energies that should create Higgs bosons in large numbers, and should be able to confirm that we're seeing them in the collisions within the next few years. We think.

If the Higgs is found, then we basically understand the universe of subatomic physics. If the Higgs is not found, it's back to the drawing board.

By the way, the best popular name I know of for the Higgs is the "champagne bottle boson."

*This is a unit of energy, but for purposes of particle physics measuring masses in electron volts and dividing by c^2 as convenient is way less work than using grams or kilograms...
______

The other thing I know of that the LHC is hoping to spot is "supersymmetry." One of the more promising sets of physical theories that go beyond the Standard Model into more exotic territory predicts that the particles we know and love (quarks, photons, leptons) will have super-massive analogues (tentatively given unimaginative and silly names like squarks, photinos, and sleptons).

These particles may have masses that are orders of magnitude greater than their normal counterparts, and so like the (we think) ~150 GeV Higgs boson, we haven't been able to observe them with existing equipment. At maximum power, the LHC should be able to create these supersymmetric partner-particles if they exist at all, which will tell us something about whether or not there's anything to this talk about supersymmetry.

[Knife]

Ok, so the models they work from on sub atomic particles is pretty much just math. As I understand it, the CERN is now smashing things together so they can observe how they interact, and either prove or disprove the math model? If that's it, I can wrap my head around it.

I don't get how a particle, Higgs Boson, gives mass though.

[Serafina]

Ok, so the models they work from on sub atomic particles is pretty much just math. As I understand it, the CERN is now smashing things together so they can observe how they interact, and either prove or disprove the math model? If that's it, I can wrap my head around it.

I don't get how a particle, Higgs Boson, gives mass though.

Well, that's pretty much it - so start wrapping that head

Basically, the Higgs-Boson is supposed to interact with other quantum-particles, and this interaction produces what we observe as mass. Yes, that means that these particles do not have mass by themself.
If you want to know more..well, it's complicated, and i am not familiar enough with it to put it in laymans terms.

[Kanastrous]

There's an expression, that a given particle "couples" to a given field, and therefore certain types of particles do or do not interact with certain fields. I suspect that the general concept is that we need to find the particle that couples to gravitational fields (the way that electrons and photons couple to electromagnetic fields) as that field's "messenger particle" (that is, the particle involved in the interactions that "tell" particles separated by space that they are being acted upon by the force produced by that field). The Higgs Boson would be a messenger particle that performs that function of 'telling' matter that it is within a gravitational field and must behave accordingly.

[Simon_Jester]

Ok, so the models they work from on sub atomic particles is pretty much just math. As I understand it, the CERN is now smashing things together so they can observe how they interact, and either prove or disprove the math model? If that's it, I can wrap my head around it.

Correct. However, the mathematical models in question are really important, insofar as our understanding subatomic physics is important. If the Standard Model is wrong, whatever replaces it will teach us some very strange, very unexpected things about the universe, over and above the ones we've already learned from 20th century physics.

I don't get how a particle, Higgs Boson, gives mass though.

Unfortunately, the only way to explain this is by explaining the underlying physics of the Standard Model. Which, it so happens, I don't actually know.

It might be possible to do a good job of explaining this without breaking out high undergraduate level math, for all I know... but I am not qualified to place a bet on it.

There's an expression, that a given particle "couples" to a given field, and therefore certain types of particles do or do not interact with certain fields. I suspect that the general concept is that we need to find the particle that couples to gravitational fields (the way that electrons and photons couple to electromagnetic fields) as that field's "messenger particle" (that is, the particle involved in the interactions that "tell" particles separated by space that they are being acted upon by the force produced by that field). The Higgs Boson would be a messenger particle that performs that function of 'telling' matter that it is within a gravitational field and must behave accordingly.

I was under the impression that it was gravitons that were responsible for this. Gravitons are likewise undetected, but for different reasons.

The Higgs boson would be responsible not for gravity, but for mass itself. Mass can matter in situations where gravity is completely irrelevant: for instance, the mass of a particle determines how fast it will move if you kick it with a given amount of energy.

[Kanastrous]

Yup, can't distinguish gravity from mass (puts on dunce cap and sits in corner...)

[CaptJodan]

Ok, so here's a stupid question from someone who might struggle with even basic math and physics.

Would finding the Higgs Boson particle be akin or in any way related to finding Dark Matter? Or is that a completely separate issue?

[Fingolfin_Noldor]

Ok, so here's a stupid question from someone who might struggle with even basic math and physics.

Would finding the Higgs Boson particle be akin or in any way related to finding Dark Matter? Or is that a completely separate issue?

The Higgs Boson is simply the mediator of mass. It has some relation to Dark Matter, but not really. Dark Matter's problem is that the particles do not interact readily with photons.

[Skgoa]

The easiest explanation of Higgs I heard is the following:
Think of the Higgs field as a room full of people. Each of these people represents a Higgs boson. Now a popular person enters the room and wants to cross to the other side. People will flock around that person and engage in conversation, making his movement through the room slow and tedious. Now an unpopular person wants to move through the crowd. They totally ignore him and he can move fast and freely. The popular person represents heavy particles, the unpopular one represents light particles.


edit: Also I would like to point out that finding that one curve that is consistently to high over month of collisions buried in terabytes of data will not be the easiest task. And even once they know they found SOMETHING new, it won't be clear for a long time what particle that is.(there is a huge number of theories and particles predicted by them) And even when they finally know they found the higgs, they STILL don't know which of the theories (well, apart from the Standard Model of course) is right, since there are - depending on the theory in question - up to five different kinds of Higgs bosons predicted and there seems to be a big chance that finding a SUSY Higgs means that its "brothers" CAN'T be seen by the LHC.
But a hadron collider isn't meant (warning: hyperbole following ) to make precise meassurements, but to smash big bunches at high speeds without costing as much as a conventional electron positron collider - which they will build once they have evidence that there actually IS more to be found.