July 9, 2012

CERN Turns LHC’s Attention To Dark Matter

Brett Smith for - Your Universe Online

Now that the ℠God Particle´ has been discovered, is it time to pack up CERN´s Large Hadron Collider (LHC) and move on to other projects?

Not so fast, say physicists who are looking to upgrade the 4-year-old particle accelerator. CERN´s governing body has just approved plans that would shut down the LHC for two years while it gets a $1.9 billion upgrade.

The improvements would theoretically increase the power of the LHC´s particle beams by tenfold and would outfit the accelerator for another purpose–the creation and detection of dark matter.

Currently, the LHC works by sending protons around a track at extreme speeds that crash into each other to produce temperatures of more than four trillion degrees Celsius. Sensors around the ring identify the material thrown out from these collisions. Scientists hope that the 2020 upgrade, dubbed “super-LHC”, will allow them to see rare particles including something they can identify as dark matter.

“It will allow us to greatly extend the reach to search for new physics as well as make some very precise measurements, for example, to potentially address the nature of dark matter,” physicist Phil Allport of the University of Liverpool told The Telegraph.

“Essentially we will be looking for a major imbalance in the particles being emitted after a collision."

Dark matter is a type of matter hypothesized to account for 84 percent of the total matter in the universe. Despite the fact that it is all around us, according to theory, it has never been seen because it does not produce or reflect light.

Despite the fact that it is not part of the predominant theory of particle physics, called the Standard Model, the possibility of dark matter first came to the attention of astrophysicist Jan Oort in 1932 who attempted to detail the orbital velocities of Milky Way stars. In 1933, Swiss astronomer Fritz Zwicky used a theory involving dark matter to account for evidence of mass-related discrepancies in orbital velocities on a much larger scale–those of galaxies found in galactic clusters.

Many scientists are expecting the newly discovered particle to be the key to unlocking the mysteries and alternative theories surrounding dark matter and how it relates to the Standard Model, if at all.

One alternative theory is known as "supersymmetry" or SUSY. Supersymmetry,  which is an extension of the Standard Model, suggests that for every known elemental particle, there is an identical particle except for its quantum spin. For instance, photons would have partner "photinos," and electroweak bosons would have duplicate "electroweak-inos” that differ from each other by half a spin unit.

Although there is no direct evidence for the existence of supersymmetry, it does offer the only "loophole" to quantum field theories because it allows many more mathematical problems to become exactly solvable. Supersymmetry is also a feature of most versions of string theory, another mathematical model that attempts to account for all fundamental forces and forms of matter.

Physicists associated with the project admit that there is still much work to be done on confirming and analyzing the Higgs boson. Other experiments involving the LHC have been scheduled until the end of this year, when it will close for 20-months repair period.