Particle Collider May Have Found New Particle – Key to Missing Antimatter

LHCb team at CERN
The LHCb team stands in front of their experiment, the LHCb detecor, at the Large Hadron Collider in Geneva. CREDIT: CERN/Maximilien Brice, Rachel Barbier

Physicists attending the Large Hadron Collider (LHC) Symposium in Paris this week have reported the results of their data analysis from recent proton collision experiments, and their preliminary findings just might herald the dawn of a ‘new age’ in quantum physics.

The LHC is a 17 mile/27 km, circular  proton collider (part of CERN) located just outside Geneva, Switzerland. Recently, physicist working at the LHC reported “hints” of the fabled Higgs Boson, the so-called ‘god particle’ (this has not been fully confirmed yet; results should be in this December).

But there has been some talk that the LHC — the most powerful ‘atom smasher’ ever built — may not fin anything new beyond this important, but predicted, boson. Some physicists have been growing disappointed, believing that this was all they would ever find.

The Newest Collider Experiment Results:

But now researchers experimenting with one of the four main detectors connected to the LHC — a detector known as LHCb (the ‘b’ stands for ‘beauty’, a ‘flavor’ of sub-atomic particles called quarks) — are reporting that some of the matter particles produced in the collisions are behaving quite differently than their antimatter counterparts.

In theory, all particles of matter have an antimatter counterpart that is in most ways just like the matter version, only with a difference in charge (and a different time direction). But this is not the case, as far as measurements go; the universe has far more matter than antimatter (known as ‘baryon asymmetry’).

One explanation for this asymmetry is known as ‘charge-parity violation’ (CP violation) which essentially says that oppositely charged particles may behave quite differently from each other (due to how they interact with other particles). These recent findings suggest that this is in fact what is happening when certain, light-weight particles called D-mesons (which contain another flavor of quark, labeled ‘charm’) decay into still other particles.

This detectable difference in matter-antimatter behavior, though small (just .8 %), is greater than what is allowed by the Standard Model of Quantum Physics. And, it could be evidence of a new class of particle that might explain one of the great mysteries of physics: why our universe is made of mostly matter, and not equal parts matter/antimatter, as symmetry theories predict that it should.

Other possibilities: other particles…extra dimensions

It could also be a signal of an even more exotic particle known as a supersymmetric partner particle (or just ‘super partner’ particle). According to Super Symmetry (SUSY) theory — an extension of the Standard Model —  such extremely short-lived, super partner particles  accompany every other particle but differ by one half unit of spin.

A superpartner particle could be interfering with the “normal” decay process as it instantaneously appears and disappears in the collision aftermath, possibly explaining the matter/antimatter asymmetry.

Superpartner particles are also connected to the theory of extra dimensions, which is fancied by Super String Theorists and may also explain where all the antimatter is going.

Could it Be Just a Fluke?

The LHCb results have been assigned a ‘3.5 Sigmas’ rating, which means that there’s less than a 5% chance that the result is a false signal (or the result of “noise” from the collisions). A bona fide particle would have a ‘5 Sigma’ rating. It will take several more months of analysis to determine if in fact this is the case. Results from this extended analysis won’t be available until sometime in 2012.

In an interview, one of the lead researchers working at the LHCb detector, Matthew Charles of England’s Oxford University, stated:

“At this point it’s a tantalizing hint. It’s evidence of something interesting going on, but we’re keeping the champagne on ice, let’s say.” [source: LiveScience]

Top photo: (The LHCb team stands in front of their experiment, the LHCb detecor, at the Large Hadron Collider in Geneva) Credit: CERN/Maximilien Brice, Rachel Barbier

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