New Revelations From Particle Colliders Past, Present & Future

By Joseph Calamia | July 27, 2010 1:03 pm

lhc-tunnelParticle physicists hunting for the Higgs boson reported their latest findings yesterday at the International Conference on High Energy Physics in Paris. The big two–Europe’s Large Hadron Collider and Fermilab’s Tevatron Collider (in Illinois)–gave updates, and other conference buzz included talk of a new facility, the International Linear Collider, which may one day give physicists a cleaner look at the other colliders’ results.

Large Hadron Collider — More Detailed Models Help the Search

Currently operating at 7  Tera electron Volts (TeV), the Large Hadron Collider is the world’s most powerful particle accelerator. Though electrical malfunctions hindered the collider in 2008, now LHC scientists report that they have made up for lost time: finding in months, what took the Tevatron, with its 2 TeV collisions, decades.

“The scientific community thought it would take one, maybe two years to get to this level, but it happened in three months,” said Guy Wormser, a top French physicist and chairman of the conference.[AFP]

As Symmetry (a Fermilab/SLAC publication) notes, these findings are more than a test of strength–or a simple retracing of the Tevatron’s footsteps. LHC physicists have to show that their facility can reproduce the results other machines have already seen, if one day they are to be sure that their data indicate something new.

As also reported by Symmetry, because the LHC is running at energies 3.5 times the Tevatron’s, these higher energies allow LHC physicists to refine their previous understandings, teasing out details impossible to see at lower energies. Such details may help physicists refine their search for the Higgs, the particle that presumably gives mass to all other particles.

CERN, the European umbrella organization that runs the LHC, says that these tests show the collider is ready for that search.

“Rediscovering our ‘old friends’ in the particle world shows that the LHC experiments are well prepared to enter new territory” said CERN’s Director-General Rolf Heuer. “It seems that the Standard Model is working as expected. Now it is down to nature to show us what is new.”[CERN]


Tevatron — Telling  Physicists Where Not to Look

Meanwhile, Tevatron researchers have narrowed the expected mass of the missing particle. The diagram above shows the expected mass ranges, and those excluded by the new Tevatron data and previous Fermilab experiments. For reference, the proton has a mass of a little less than one GeV/c^2.

[P]hysicists’ standard model of the fundamental particle does not predict how much the Higgs itself will weigh. So scientists must go searching for it. Previous experiments show that it probably has a mass between 114 and 185 giga-electron volts (GeV), or 121 and 197 times the mass of the proton. Last year, experimenters working with D0 (aka DZero) and the Tevatron’s other particle detector, CDF [Collider Detector at Fermilab], took a chunk out of that possible range, reporting that the Higgs most likely does not weigh between 162 GeV and 166 GeV. Now, they’ve widened that “exclusion window” to between 158 GeV and 175 GeV.[Science Now]

Given such results, physicists have submitted a proposal to Fermilab asking that the Tevatron’s life be extended beyond 2011 to 2014, but the lab can’t guarantee that given its limited resources and other ongoing experiments and new projects.

Currently CERN officials have scheduled an LHC shutdown for 15 months also in 2011, which might give an operating Tevatron a chance to find the Higgs, Robert Roser of the Tevatron’s CDF detector told The Guardian.

“The LHC won’t be able to say anything about the Higgs particle until well into 2013. If we can run until 2014, we should be able to see the Higgs boson whatever mass it has,” said Roser. [The Guardian]

International Linear Collider — A Future, Cleaner Look?

Given results from the LHC and Fermilab, scientists continue to discuss new colliders, such as the International Linear Collider. Unlike the Tevatron and the LHC, which spin particles in a circle and then collide them, the International Linear Collider will force electrons and their antimatter-pair, positrons, to face off in a straight, approximately 20-mile long tube. Researchers say the collider would complement ongoing research at the LHC, by giving scientists a less powerful but cleaner look at the data, in part because the linear setup will ensure that particles that didn’t smash in the initial collision won’t continue circulating through the detector, Popular Science reports. They hope to start building the detector in 2012, but it will require international funding, the AP reports, amounting to $12.85 billion. Barry Barish, director of the proposed collider, told the AP:

“If we are going to build an ambitious machine, then it’s got to be a global machine.”[AP]

A video describing the ILC is available, here.

Related content:
80beats: LHC Sets a New Personal Record: 10,000 Particle Smash-Ups per Second
80beats: A Sweet Smashup: The LHC Shatters the Collison Energy Record
80beats: In 1 Week, the LHC Will Try to Earn the Title, “Big Bang Machine”
80beats: Rumors of the LHC’s Demise Have Been Greatly Exaggerated
80beats: LHC Beam Zooms Past 1 Trillion Electron Volts, Sets World Record

Images: CERN, Fermilab

  • Sylwester Kornowski

    The Higgs boson(s) and Higgs mechanism are not in existence. Particles acquire their masses due to the internal structure and properties of the Einstein spacetime. The Einstein spacetime is a gas composed of the non-rotating binary systems of neutrinos. Photons are the excitations of local Einstein spacetime – they are the rotational energies of the binary systems of neutrinos. The Planck time is typical for the lifetime in excited state i.e. in state when the binary systems of neutrinos rotate. It causes that energy (a photon) disappears in one place of the Einstein spacetime and appears in another one and so on – in such way behave the quantum particles. It is very difficult to detect the non-rotating binary systems of neutrinos because they cannot transfer energy to a detector. Particles having mass consist of the bound binary systems of neutrinos. Their mean mass density is higher than the Einstein spacetime due to the possible phase transitions. Relativistic mass is due to the law of conservation of spin. Properties of the Einstein spacetime follow from the properties of the more fundamental Newtonian spacetime – it is gas composed of tachyons having positive mass. We can describe the whole matter and energy applying only seven parameters describing the Newtonian (6) and Einstein (1) spacetimes. These seven parameters lead to the physical constants and mathematical constants applied in physics.

  • Tom Croley

    I don’t think that smashing something together at high speeds and studying what flies off of the collision is an accurate method of discovering how things are really put together. Could you discover how a car is made by watching two cars smash head on at high speeds? If you smashed them enough times, you would observe certain repeatable phenomena like certain parts that always fly off the same way at certain speeds. But the whole process would not reveal the true engineering that went into the car. If fact, it may lead to some false conclusions as some parts fuse together at higher speeds and other parts disintegrate that would not normally do so at lower speeds. For this reason, this aspect of physics will always be a matter of speculation.


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