Discovery: The LHC's Higgs Boson Treasure Hunt Begins

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Discovery: The LHC's Higgs Boson Treasure Hunt Begins

Post by bystander » Wed May 19, 2010 12:32 pm

The LHC's Higgs Boson Treasure Hunt Begins
Discovery Space News - 18 May 2010

As you're probably aware, the Large Hadron Collider (LHC) was built under the France-Swiss border near Geneva to hunt down a missing piece in a modern physics puzzle: the Higgs boson. And now LHC scientists think they are getting close to tracking down the particle that has, up until now,existed only in equations.

Put simply, the LHC has pushed us into a particle physics no-man's land where the Higgs boson is only one component of this adventure.

ARTICLE: What is the Higgs boson and how will the search for this elusive particle affect everyday life?

Higgs Treasure

It's almost like a high-tech treasure hunt, where you have a vague map to constrain the location of the "X that marks the spot" on some desert island in an ocean of other islands. But up until now your boat has been hopelessly underpowered and could only transport you to the closest islands.

Now physicists have the LHC -- a 'boat' powerful enough to reach all of the known islands in the particle physics ocean so they can land on every desert island as far as the eye can see. Each island represents a new mystery treasure to be dug up, but the furthest islands require the most energy to get there.

Although the hunt for the Higgs boson forms the backbone of the LHC quest (and indeed it would make for a priceless treasure), there's a lot of "new physics" along the way that physicists hope to dig up.

(In fact, there are some physicists who don't want to find the Higgs boson as, quite frankly, it would be more exciting if we discover our current understanding of universal physics is wrong.)

SLIDE SHOW: Top 5 Misconceptions About The LHC

LHC Confirmation of the Weak Force?

The Higgs boson treasure hunt is progressing rather nicely so far (despite a bumpy beginning) and the first priority is to make sure the monster detectors located at strategic points around the LHC's 17-mile ring of superconducting magnets can recognize known particles.

Already LHC physicists using the ATLAS experiment have identified what appear to be lower-mass W bosons from their "decay products" after colliding high-speed protons head-on.

W (and Z) "gauge" bosons carry the weak force, one of the four fundamental forces known to exist in nature (the other forces are gravity, the electromagnetic and strong). The weak force is responsible for the decay of neutrons, producing proton and electron (or positron) decay products.

So, LHC physicists have "seen" these decay products and deduced that low-mass W bosons are most likely responsible.

WIDE ANGLE: Will the Large Hadron Collider herald a revolution in our understanding of the cosmos?

Anti-Matter and a Strange Beauty

Currently, the LHC is operating at half-power (and will probably continue to do so until 2011), but even at half-power, the accelerator is breaking records. The detection of known particles is also a reassuring sign that things are working as they should.

In the next few months, it is expected that the LHC will be able to generate heavier particles, and the hunt is currently on for what are known as "W prime" and "Z prime" bosons, the heavier cousins of the W gauge bosons.

W prime and Z prime bosons have never been seen inside a particle accelerator before, so these are the first items of treasure predicted (by our current understanding of particle physics) to be physically discovered for the first time.

In another LHC detector (the LHCb), exotic particles have been detected after colliding beams of protons. Quarks are most commonly known as the building blocks of protons and neutrons, but at high enough collision energies, exotic particles can be produced.

"Charm" quarks and "Strange Beauty" particles (a combination of one "Beauty" quark and one "Strange" anti-quark) have been confirmed, sparking a wave of excitement amongst physicists charged with using the LHCb detector.

"This is the first of a type of particle [the Strange Beauty particle] that we're going to use to try to give us a handle on anti-matter and why it behaves differently to normal matter," Tara Shears, of the University of Liverpool, told BBC News.

"We're going to use matter and anti-matter versions of this particular particle to really probe our understanding of what's going on in a way that we haven't been able to with other experiments."

A Journey of Discovery

This finding will aid our understanding as to why our Universe is composed of matter and not anti-matter. Matter and anti-matter annihilate, so it's a very good thing that the Universe has a bias toward "normal" matter (otherwise we wouldn't exist), but theory suggests that the Universe should be composed of both in equal measures. By studying the Strange Beauty particle, perhaps we will understand why matter dominates.

Although the LHC is well on its way to perform an extended campaign of science, don't get excited for the early detection of the Higgs particle. The Higgs is predicted to be even more massive than the particles detected so far, so more calibration of the LHC is required before collision energies can be amplified any further.

Like all good treasure hunts, it's not necessarily the treasure that's the most exciting goal. The journey of discovery as we pursue the Higgs particle will produce many unforeseen benefits for science along the way, enriching our everyday lives. Besides, what happens when the LHC takes us into uncharted territory (i.e. the 'islands' currently located on our theoretical horizons)? Will there be another ocean filled with islands that represent deeper physics than we ever thought possible?

Just in case you were in any doubt of the fact that the LHC was one of the most audacious experiments of our time, watch Brian Cox, an ATLAS physicist, in action during a heated debate when the LHC first went online in 2008:
[youtube] ... r_embedded[/youtube]

WATCH VIDEO: Discovery News investigates
how and why the Large Hadron Collider is
smashing protons together at record energies.