The Large Hadron Collider: We’ve Definitely Found the Higgs Boson

higgs-boson1In July 2012, the CERN laboratory in Geneva, Switzerland made history when it discovered an elementary particle that behaved in a way that was consistent with the proposed Higgs boson – otherwise known as the “God Particle”. Now, some two years later, the people working the Large Hadron Collider have confirmed that what they observed was definitely the Higgs boson, the one predicted by the Standard Model of particle physics.

In the new study, published in Nature Physics, the CERN researchers indicated that the particle observed in 2012 researchers indeed decays into fermions – as predicted by the standard model of particle physics. It sits in the mass-energy region of 125 GeV, has no spin, and it can decay into a variety of lighter particles. This means that we can say with some certainty that the Higgs boson is the particle that gives other particles their mass – which is also predicted by the standard model.

CERN_higgsThis model, which is explained through quantum field theory  – itself an amalgam of quantum mechanics and Einstein’s special theory of relativity – claims that deep mathematical symmetries rule the interactions among all elementary particles. Until now, the decay modes discovered at CERN have been of a Higgs particle giving rise to two high-energy photons, or a Higgs going into two Z bosons or two W bosons.

But with the discovery of fermions, the researchers are now sure they have found the last holdout to the full and complete confirmation that the Standard Model is the correct one. As Marcus Klute of the CMS Collaboration said in a statement:

Our findings confirm the presence of the Standard Model Boson. Establishing a property of the Standard Model is big news itself.

CERN_LHCIt is certainly is big news for scientists, who can say with absolute certainty that our current conception for how particles interact and behave is not theoretical. But on the flip side, it also means we’re no closer to pushing beyond the Standard Model and into the realm of the unknown. One of the big shortfalls of the Standard Model is that it doesn’t account for gravity, dark energy and dark matter, and some other quirks that are essential to our understanding of the universe.

At present, one of the most popular theories for how these forces interact with the known aspects of our universe – i.e. electromagnetism, strong and nuclear forces – is supersymmetry.  This theory postulates that every Standard Model particle also has a superpartner that is incredibly heavy – thus accounting for the 23% of the universe that is apparently made up of dark matter. It is hoped that when the LHC turns back on in 2015 (pending upgrades) it will be able to discover these partners.

CERN_upgradeIf that doesn’t work, supersymmetry will probably have to wait for LHC’s planned successor. Known as the “Very Large Hadron Collider” (VHLC), this particle accelerator will measure some 96 km (60 mile) in length – four times as long as its predecessor. And with its proposed ability to smash protons together with a collision energy of 100 teraelectronvolts – 14 times the LHC’s current energy – it will hopefully have the power needed to answer the questions the discovery of the Higgs Boson has raised.

These will hopefully include whether or not supersymmetry holds up and how gravity interacts with the three other fundamental forces of the universe – a discovery which will finally resolve the seemingly irreconcilable theories of general relativity and quantum mechanics. At which point (and speaking entirely in metaphors) we will have gone from discovering the “God Particle” to potentially understanding the mind of God Himself.

I don’t think I’ve being melodramatic!

Source: extremetech.com, blogs.discovermagazine.com

The Amplituhedron: Quantum Physics Decoded

amplutihedron_spanScientists recently made a major breakthrough that may completely alter our perceptions of quantum physics, and the nature of the universe itself. After many decades of trying to reformulate quantum field theory, scientists at Harvard University discovered of a jewel-like geometric object that they believe will not only simplify quantum science, but even challenge the notion that space and time are fundamental components of reality.

This jewel has been named the “amplituhedron”, and it is radically simplifying how physicists calculate particle interactions. Previously, these Interactions were calculated using quantum field theory – mathematical formulas that were thousands of terms long. Now, these interactions can be described by computing the volume of the corresponding amplituhedron, which yields an equivalent one-term expression.

theory_of_everythingJacob Bourjaily, a theoretical physicist at Harvard University and one of the researchers who developed the new idea, has this to say about the discovery:

The degree of efficiency is mind-boggling. You can easily do, on paper, computations that were infeasible even with a computer before.

This is exciting news, in part because it could help facilitate the search for a Grand Unifying Theory (aka. Theory of Everything) that manages to unify all the fundamental forces of the universe. These forces are electromagnetism, weak nuclear forces, strong nuclear forces, and gravity. Thus far, attempts at resolving these forces have run into infinities and deep paradoxes.

gravityWhereas the field of quantum physics has been able to account for the first three, gravity has remained explainable only in terms of General Relativity (Einstein’s baby). As a result, scientists have been unable to see how the basic forces of the universe interact on a grand scale, and all attempts have resulted in endless infinities and deep paradoxes.

The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity. Locality is the notion that particles can interact only from adjoining positions in space and time, while unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one.

quantum_field_theoryThe concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature. As Nima Arkani-Hamed – a professor of physics at the Institute for Advanced Study in Princeton, N.J. and the lead author of the new work – put it: “Both are hard-wired in the usual way we think about things. Both are suspect.”

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions. The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.

Photon_follow8And while the amplituhedron itself does not describe gravity, Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time. This is because, as Bourjaily put it:

[W]e know that ultimately, we need to find a theory that doesn’t have [unitarity and locality]. It’s a starting point to ultimately describing a quantum theory of gravity.

Imagine that. After decades of mind-boggling research and attempts at resolving the theoretical issues, all existence comes down to a small jewel-shaped structure. I imagine the Intelligent Design people will have a field day with this, and I can foresee it making it into the new season of Big Bang Theory as well. Breakthroughs like this always do seem to have a ripple effect…

Source: simonsfoundation.org

Higgs Boson Confirmed!

CERN_tunnelIn July of 2012, scientists working for the CERN Laboratory in Geneva, Switzerland announced that they believed they had found the elusive “God Particle” – aka. the Higgs Boson. In addition to ending a decades-long search, the discovery also solved one of the greatest riddles of the universe, confirming the Standard Model of particle physics and shedding light on how the universe itself came to be.

But of course, this discovery needed to be confirmed before the scientific community could accept its existence as fact. The announcement made in July indicated that what the CERN scientists had found appeared to be the Higgs Boson, in that it fit the characteristics of the hypothetical subatomic particle. But as of last Thursday, they claimed that they are now quite certain that this is what they observed.

CERNJoe Incandela, a physicist who heads one of the two main teams at CERN (both made up of over 3000 individuals) claimed that: “To me it is clear that we are dealing with a Higgs boson, though we still have a long way to go to know what kind of Higgs boson it is”. In essence, he and his staff believe that may be several types of Higgs to be found, each of which behaves a little differently.

This was no small challenge, as the Higgs will only make an appearance once in every trillion collisions. Originally theorized in 1964 by British physicist Peter Higgs to explain why matter has mass, it has long been suspected that the Higgs stood alone, explaining how the six “flavors” of quarks, six types of leptons, and twelve gauge bosons, interact. Now, it may be the case that there are several, each of which moves differently and are responsible for different functions.

Higgs-bosonAnd of course, there are several larger mysteries that remain to be solved, which the discovery of the Higgs is expected to shed light on. These include why gravity is so weak, what the dark matter is that is believed to make up a large part of the total mass in the universe, and just how all the major forces of the universe work together to define this thing we know as reality.

These include gravity, weak and strong nuclear forces, and electromagnetism. The Theory of Relativity explains how gravity works, while Quantum Theory explains the other three. What has been missing for some time is a “Grand Unifying Theory”, something which could explain how these two theories could co-exist and account for all the basic forces of the universe.

If we can do that, we will have accomplished what Stephen Hawking has dreamed of for some time, and in effect be one step closer to what he described as: “understanding the mind of God”.

Source: nytimes.com