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LHC Upgrade May Lead To New Dimension In Particle Physics

April 3, 2013
Image Credit: CERN/Maximilien Brice (2009)

April Flowers for redOrbit.com – Your Universe Online

Engineers at the Large Hadron Collider (LHC) in Cern, Switzerland have begun the process of upgrading. The $105-million upgrade should double the potential energy of what is already the world’s most powerful particle accelerator.

BBC News reports that the scientists believe the upgrade will enable them to discover more new particles like the Higgs boson discovery last year that will lead to a more complete theory of how the Universe works.

Dr. Pippa Wells, project leader with the LHC’s ATLAS experiment, said there was much more to come from the LHC.

“The past two years have been the most exciting in my time as a particle physicist. People are absolutely fired up. They’ve made one new discovery (the Higgs) and they want to make more discoveries with the new high energies that the upgrade will give us. We could find a new realm of particle physics.”

Creating the conditions of the early Universe is no mean feat. Buried more than 300 feet below the Earth’s surface, the LHC is one of the most complex machines ever built and a masterpiece of technical engineering. A bright blue superconducting beamline stretches approximately 17 miles, with gleaming precision instruments that help make the line one of the coldest places in the Universe.

More than 10,000 connectors will need to be changed in the upgrade, involving over 800 people. The upgrade will also include testing and replacing some of the LHC’s main dipole and quadrupole magnets which are used to bend the paths of the particles and keep them tightly bunched; conducting tests to detect any irregularities in the magnets or imperfections in the electrical insulation; and a range of other work to improve the machine.

“We are always at the limit of what we know in terms of the technology. It is very exciting: as the coordinator. I have access to all the technologies and they really are at their limit in terms of superconductivity cryogenics. It is very exciting for an engineer to be close to all these new technologies,” said Katy Foraz, technical coordinator for the upgrade project.

Critics are calling this two-year shut down a repair rather than an upgrade, charging that this expensive refit is intended to correct a mistake that should not have been made.

“Nobody has ever done this kind of technology before. Everything from the most basic welding to the most complicated beam diagnostics is pushing the boundaries of technology, and sometimes these things just don’t go right simply because we don’t know how it’s going to work,” Foraz responded.

“You can see in front of us the way that we’re managing the upgrade is meticulous. There is lots and lots of quality control (sic), making sure that everything’s absolutely spot-on so that when we turn the machine back on we are absolutely ready for some more fantastic scientific discoveries.”

The damage to the equipment occurred shortly after the LHC came online in 2008. It was a result of connections that were not able to handle the electrical current passing through them.

THE SEARCH FOR DARK MATTER

One new area of research likely to garner attention, according to The Telegraph, is the hunt for dark matter. Dark matter is a substance that physicists theorize makes up about 85 percent of the matter in our Universe. In comparison, “normal” matter — the stuff we are made from — is thought to account for less than five percent.

Dark matter gives the universe structure, acting as a “cosmic glue.” It is responsible for forming galaxies and holding them together. However, dark matter has never been directly observed, and its existence has until now only been inferred by the slight gravitational pull it exerts on other matter.

The LHC will have a greater capacity for creating high-energy particle collisions after the reopening in 2015. Scientists hope they will then finally be able to replicate the conditions that were present at the Big Bang and perhaps even create small amounts of dark matter.

Dr. Alan Barr, of the LHC’s ATLAS experiment, explained, “If we could produce our own in the lab we would be able to study it and learn what it is made of, where it comes from and how it is related to normal matter.”

“That would also allow us to understand much more about what is the dominant form of matter in the Universe.”

It isn’t yet known whether the current upgrade will be powerful enough to create dark matter or if that will have to wait until the next scheduled upgrade in 2020. However, CERN scientists are optimistic that this power boost will open up the door for “new physics.”

Dr. Wells told the BBC, ”People are absolutely fired up. They’ve made one new discovery (the Higgs) and they want to make more discoveries with the new high energies that the upgrade will give us. We could find a new realm of particle physics.”

AN EXTRA DIMENSION?

Like a jigsaw puzzle slowly being completed, the Standard Model of particle physics is coming together. Most pieces fit reasonably well and are compatible with predictions from the Standard Model. Some physicists, however, are hoping for results that don’t fit the puzzle because they might point the way to those “new physics.”

Dr. Jonas Rademacker of the University of Bristol and the LHC beauty (LHCb) collaboration is one of those hoping that the puzzle won’t go back together quite the same way.

“We´re hoping to find the jigsaw piece that looks like it should fit, but when you look very closely, the pattern isn´t quite right,” he says.

Offering an unprecedented level of detail and precision, Rademacker has developed a new method for analyzing data from the LHCb that requires the analysis special scatter plots called Dalitz plots in five dimensions rather than two. Dalitz plots represent the strange quantum-mechanical interference effects observed in particle decay. Rademacker and colleagues use this plots at LHCb to measure CP violation.

Five-dimensional analysis is a complicated process, but Rademacker thinks it is worth the effort because it significantly increases the precision of LHCb measurements.


Source: April Flowers for redOrbit.com - Your Universe Online