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The Daily Wildcat

The Daily Wildcat

 

ATLAS project searches for dark matter using high energy collisions

With the one year anniversary of the conclusive discovery of the Higgs Boson upon us, physicists may finally have the key to unlocking the mystery of the accelerating expansion of our universe.

Scientists from the UA’s ATLAS Project’s high-energy research team, in collaboration with CERN, the European Organization for Nuclear Research, are tackling this phenomenon by recreating dark matter with high energy collision experiments that have the potential to render current physics models invalid.

“The universe is expanding faster and faster as it gets older,” said Erich Varnes, associate professor of physics at the UA and a member of the ATLAS Project. “There are reasons to believe our current theories aren’t the final answer.”

In 1998, an experiment by the European Southern Observatory established the conclusion that the expansion of the universe is exponential and ever increasing.

This occurrence seems to be the result of an enigmatic presence: dark energy.

“Dark energy is something that appears to be pushing all the galaxies away from each other,” Varnes said. “That’s really all we know.”

Dark energy is a “form of energy to detect to make sure the energy balance of the universe comes out to zero,” said Peter Loch, research scientist for the UA ATLAS Project.

The team is still analyzing the data from the past two years to look for specific new particle types in an effort to understand more about what types of matter exist in the universe.

The Higgs Boson has given the scientific community probable cause to postulate the existence of various types of undiscovered matter. One such hypothesized form is known as dark matter, only capable of being identified through the observance of its gravitational pull.

“Dark matter is some form of particle we don’t know about,” Varnes said. “Essentially, dark matter is composed of all the types of unknown unknowns in what we refer to as ‘space’.

“We know there’s no electric charge [characteristic of dark matter],” Varnes continued, “but we don’t know what makes up the dark matter.”

In March 2013, the Planck Mission Team mapped the cosmic microwave background, exploring the radiation pulsating throughout the universe after the Big Bang.

The team produced a mass-energy analysis of the universe, proposing that the universe is composed of 26.8 percent dark matter and 68.3 percent dark energy.

“What we are looking for,” Loch said, “are signs of new physics in the new data. We look for deviations from what you know. If you find something, then you can think about what could it be — what kind of new physics is it?”

At the UA, Varnes and his fellow colleagues will be synthesizing dark matter for the world’s highest-energy collider, CERN’s Large Hadron Collider.

“Now it depends on the actual nature of the dark matter whether we can reproduce it on the LHC or not,” Varnes said.
Currently, the UA ATLAS Project is analyzing data from the LHC’s most recent experiments. The group is working on completely new types of detectors, attempting to increase the rates of collisions.

“By creating very high energy collisions, we can find evidence,” Loch said. “However, science is not yet at a point where it can recreate the same high energy collisions that happened at the Big Bang.”

While they may not be able to recreate the big bang, the high energy collisions will still provide a way to look for new particles.

The higher the energy of the collisions, the more rare particles will appear. The rarer the particles scientists can observe, the closer we will be to understanding the mystery of existence.

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