Thursday, March 14, 2013

The God Particle Confirmed - Higgs Bosom and the Hadron Collider

I believe that science reaffirms God's existence.  And news coming out of Italy reaffirms this belief.  No, it is not the news of Pope Francis becoming the 266th successor to Saint Peter, but rather groundbreaking confirmation from the world of molecular physicist that the "Higgs bosom", also known as the 'God Particle' has indeed been discovered.
A newfound particle discovered at the world's largest atom smasher last year is, indeed, the Higgs boson, the particle thought to give other matter its mass, scientists reported today (March 14) at the annual Rencontres de Moriond conference in Italy.
Previously, physicists announced on July 4, 2012, that, with more than 99 percent certainty, they had found a new elementary particle weighing about 126 times the mass of the proton that was likely the long-sought Higgs boson. The Higgs is sometimes referred to as the "God particle".
But the two experiments, CMS and ATLAS, hadn't collected enough data to say the particle was, for sure, the Higgs boson, the last undiscovered piece of the puzzle predicted by the Standard Model, the reigning theory of particle physics.
Now, after collecting two and a half times more data inside the Large Hadron Collider (LHC) — where protons zip at near light-speed around the 17-mile-long (27 kilometer) underground ring beneath Switzerland and France — physicists say the particle is the Higgs. [In Photos: Searching for the Higgs Boson]
"The preliminary results with the full 2012 data set are magnificent and 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," said CMS spokesperson Joe Incandela in a statement.
Dave Charlton, ATLAS spokesperson agreed, the new results "point to the new particle having the spin-parity of a Higgs boson as in the Standard Model," referring to a quantum property of elementary particles.
To confirm the particle as the Higgs boson, physicists needed to collect tons of data that would reveal its quantum properties as well as how it interacted with other particles. For instance, a Higgs particle should have no spin and its parity, or the measure of how its mirror image behaves, should be positive, both of which were supported by data from the ATLAS and CMS experiments.
Even so, the scientists are not sure whether this Higgs boson is the one predicted by the Standard Model or perhaps the lightest of several bosons predicted to exist by other theories.
Seeing how this particle decays into other particles could let physicists know whether this Higgs is the "plain vanilla" Standard Model Higgs. Detecting a Higgs boson is rare, with just one observed for every 1 trillion proton-proton collisions. As such, the LHC physicists say they need much more data to understand all of the ways in which the Higgs decays.
From what is known about the particle now, physicists have said the Higgs boson may spell the universe's doom in the very far future. That's because the mass of the Higgs boson is a critical part of a calculation that portends the future of space and time. Its mass of 126 times the mass of the proton is just about what would be needed to create a fundamentally unstable universe that would lead to a cataclysm billions of years from now.
"This calculation tells you that many tens of billions of years from now there'll be a catastrophe," Joseph Lykken, a theoretical physicist at the Fermi National Accelerator Laboratory in Batavia, Ill., said last month at the annual meeting of the American Association for the Advancement of Science.
"It may be the universe we live in is inherently unstable, and at some point billions of years from now it's all going to get wiped out," added Lykken, a collaborator on the CMS experiment.
What Exactly is the Higgs bosom?
In order to truly understand what the Higgs boson is, however, we need to examine one of the most prominent theories describing the way the cosmos works: the standard model.
It is clear that the news coming from Italy affirms the standard model.
The model comes to us by way of particle physics, a field filled with physicists dedicated to reducing our complicated universe to its most basic building blocks. It's a challenge we've been tackling for centuries, and we've made a lot of progress. First we discovered atoms, then protons, neutrons and electrons, and finally quarks and leptons (more on those later). But the universe doesn't only contain matter; it also contains forces that act upon that matter. The standard model has given us more insight into the types of matter and forces than perhaps any other theory we have.
Here's the gist of the standard model, which was developed in the early 1970s: Our entire universe is made of 12 different matter particles and four forces [source: European Organization for Nuclear Research]. Among those 12 particles, you'll encounter six quarks and six leptons. Quarks make up protons and neutrons, while members of the lepton family include the electron and the electron neutrino, its neutrally charged counterpart. Scientists think that leptons and quarks are indivisible; that you can't break them apart into smaller particles. Along with all those particles, the standard model also acknowledges four forces: gravity, electromagnetic, strong and weak.
As theories go, the standard model has been very effective, aside from its failure to fit in gravity.
Armed with it, physicists have predicted the existence of certain particles years before they were verified empirically. Unfortunately, the model still has another missing piece -- the Higgs boson. What is it, and why is it necessary for the universe the standard model describes to work? Let's find out.
As it turns out, scientists think each one of those four fundamental forces has a corresponding carrier particle, or boson, that acts upon matter. That's a hard concept to grasp. We tend to think of forces as mysterious, ethereal things that straddle the line between existence and nothingness, but in reality, they're as real as matter itself.
Some physicists have described bosons as weights anchored by mysterious rubber bands to the matter particles that generate them. Using this analogy, we can think of the particles constantly snapping back out of existence in an instant and yet equally capable of getting entangled with other rubber bands attached to other bosons (and imparting force in the process).
Scientists think each of the four fundamental ones has its own specific bosons. Electromagnetic fields, for instance, depend on the photon to transit electromagnetic force to matter. Physicists think the Higgs boson might have a similar function -- but transferring mass itself.
Can't matter just inherently have mass without the Higgs boson confusing things? Not according to the standard model. But physicists have found a solution. What if all particles have no inherent mass, but instead gain mass by passing through a field? This field, known as a Higgs field, could affect different particles in different ways. Photons could slide through unaffected, while W and Z bosons would get bogged down with mass. In fact, assuming the Higgs boson exists, everything that has mass gets it by interacting with the all-powerful Higgs field, which occupies the entire universe. Like the other fields covered by the standard model, the Higgs one would need a carrier particle to affect other particles, and that particle is known as the Higgs boson.
 On July 4, 2012, scientists working with the Large Hadron Collider (LHC) announced their discovery of a particle that behaves the way the Higgs boson should behave. The results, while published with a high degree of certainty, are still somewhat preliminary. Some researchers are calling the particle "Higgslike" until the findings -- and the data -- stand up to more scrutiny. Regardless, this finding could usher in a period of rapid discovery about our universe.
Here are 5 Possible Major Implications of the Higgs bosom confirmation.
The Origin of Mass
The Higgs boson has long been thought the key to resolving the mystery of the origin of mass. The Higgs boson is associated with a field, called the Higgs field, theorized to pervade the universe. As other particles travel though this field, they acquire mass much as swimmers moving through a pool get wet, the thinking goes.
"The Higgs mechanism is the thing that allows us to understand how the particles acquire mass," said Joao Guimaraes da Costa, a physicist at Harvard University who is the Standard Model Convener at the LHC's ATLASexperiment. "If there was no such mechanism, then everything would be massless."
If physicists confirm that the Higgs boson exists, the discovery would also confirm that the Higgs mechanism for particles to acquire mass is correct. And, it may offer clues to the next mystery down the line, which is why individual particles have the masses that they do.
"That could be part of a much larger theory," said Harvard University particle physicist Lisa Randall."Knowing what the Higgs boson is, is the first step of knowing a little more about what that theory could be. It's connected."
The Standard Model
The Standard Model is the reigning theory of particle physics that describes the universe's very small constituents.
Every particle predicted by the Standard Model has been discovered — except one: the Higgs boson.
"It's the missing piece in the Standard Model," said Jonas Strandberg, a researcher at CERN working on the ATLAS experiment. "So it would definitely be a confirmation that the theories we have now are right. If we don't [find the Higgs] it means we made some assumptions that are wrong, and we have to go back to the drawing board."
While the discovery of the Higgs boson would complete the Standard Model, and fulfill all its current predictions, the Standard Model itself isn't thought to be complete. It doesn't encompass gravity (so don't count on catching that fly ball), for example, and leaves out the dark matter thought to make up 98 percent of all matter in the universe.
"The Standard Model describes what we have measured, but we know it doesn’t have gravity in it, it doesn't have dark matter," said CERN physicist William Murray, the senior Higgs convener at ATLASand a physicist at the U.K.'s Science and Technology Facilities Council."So we're hoping to extend it to include more."
The Electroweak Force
Discovering the Higgs boson would also help explain how two of the fundamental forces of the universe — the electromagnetic force that governs interactions between charged particles, and the weak force that's responsible for radioactive decay — can be unified.
Every force in nature is associated with a particle. The particle tied to electromagnetism is the photon, a tiny, massless particle. The weak force is associated with particles called the W and Z bosons, which are very massive.
The Higgs mechanism is thought to be responsible for this.
"If you introduce the Higgs field, the W and Z bosons mix with the field, and through this mixing they acquire mass," Strandberg said."This explains why the W and Z bosons have mass, and also unifies the electromagnetic and weak forces into the electroweak force."
Discovering the Higgs boson would also help explain how two of the fundamental forces of the universe — the electromagnetic force that governs interactions between charged particles, and the weak force that's responsible for radioactive decay — can be unified.
Every force in nature is associated with a particle. The particle tied to electromagnetism is the photon, a tiny, massless particle. The weak force is associated with particles called the W and Z bosons, which are very massive.
The Higgs mechanism is thought to be responsible for this.
"If you introduce the Higgs field, the W and Z bosons mix with the field, and through this mixing they acquire mass," Strandberg said. "This explains why the W and Z bosons have mass, and also unifies the electromagnetic and weak forces into the electroweak force."
Though other evidence has helped buffer the union of these two forces, the discovery of the Higgs would seal the deal. "That's already pretty solid," Murray said. "What we're trying to do now is find really the crowning proof."
Another theory that would be affected by the discovery of the Higgs is called supersymmetry. This idea posits that every known particle has a "superpartner" particle with slightly different characteristics.
Supersymmetry is attractive because it could help unify some of the other forces of nature, and even offers a candidate for the particle that makes up dark matter. Depending on the actual mass of the Higgs boson, it could lend credence to supersymmetry, or cast doubt on the theory.
"If the Higgs boson is found at a low mass, which is the only window still open, this would make supersymmetry a viable theory," Strandberg said."We'd still have to prove supersymmetry exists."
Validation of LHC
The Large Hadron Collider is the world's largest particle accelerator. It was built for around $10 billion by the European Organization for Nuclear Research (CERN) to probe higher energies than had ever been reached on Earth. Finding the Higgs boson was touted as one of the machine's biggest goals.
The discovery of the Higgs would offer major validation for the LHC and for the scientists who've worked on the search for many years.
"If the Higgs eventually gets discovered it would be a very big step," said Guimaraes da Costa. "You have to invest lots of years, and getting to see it is quite exciting. It's quite good for the field because to build these machines [it] costs a lot of money, and you need to justify why we build these machines. If we make such an important discovery about the universe, it's a justification for why we should be investing in these things."
The discovery of the Higgs would also have major implications for scientist Peter Higgs and his colleagues who first proposed the Higgs mechanism in 1964.
"If it is found there are several people who are going to get a Nobel prize," said Vivek Sharma, a physicist at the University of California, San Diego, and the leader of the Higgs search at LHC's CMS experiment.
How Does The Hadron Collidor Work
One hundred meters (or about 328 feet) underground, beneath the border between France and Switzerland, there's a circular machine that might reveal to us the secrets of the universe. Or, according to some people, it could destroy all life on Earth instead. One way or another, it's the world's largest machine and it will examine the universe's tiniest particles. It's the Large Hadron Collider (LHC).
The LHC is part of a project helmed by the European Organization for Nuclear Research, also known as CERN. The LHC joins CERN's accelerator complex outside of Geneva, Switzerland. Once it's switched on, the LHC will hurl beams of protons and ions at a velocity approaching the speed of light. The LHC will cause the beams to collide with each other, and then record the resulting events caused by the collision. Scientists hope that these events will tell us more about how the universe began and what it's made of.
The LHC is the most ambitious and powerful particle accelerator built to date. Thousands of scientists from hundreds of countries are working together -- and competing with one another -- to make new discoveries. Six sites along the LHC's circumference gather data for different experiments. Some of these experiments overlap, and scientists will be trying to be the first to uncover important new information.
The purpose of the Large Hadron Collider is to increase our knowledge about the universe. While the discoveries scientists will make could lead to practical applications down the road, that's not the reason hundreds of scientists and engineers built the LHC. It's a machine built to further our understanding. Considering the LHC costs billions of dollars and requires the cooperation of numerous countries, the absence of a practical application may be surprising.

What Is the LHC Looking For?

In an attempt to understand our universe, including how it works and its actual structure, scientists proposed a theory called the standard model. This theory tries to define and explain the fundamental particles that make the universe what it is. It combines elements from Einstein's theory of relativity with quantum theory. It also deals with three of the four basic forces of the universe: strong nuclear force, weak nuclear force and electromagnetic force. It does not address the effects of gravity, the fourth fundamental force.
The Standard Model makes several predictions about the universe, many of which seem to be true according to various experiments. But there are other aspects of the model that remain unproven. One of those is a theoretical particle called the Higgs boson particle.
The Higgs boson particle may answer questions about mass. Why does matter have mass? Scientists have identified particles that have no mass, such as neutrinos. Why should one kind of particle have mass and another lack it? Scientists have proposed many ideas to explain the existence of mass. The simplest of these is the Higgs mechanism. This theory says that there may be a particle and a corresponding mediating force that would explain why some particles have mass. The theoretical particle has never been observed and may not even exist. Some scientists hope the events created by the LHC will also uncover evidence for the existence of the Higgs boson particle. Others hope that the events will provide hints of new information we haven't even considered yet.
A­nother question scientists have about matter deals with early conditions in the universe. During the earliest moments of the universe, matter and energy were coupled. Just after matter and energy separated, particles of matter and antimatter annihilated each other. If there had been an equal amount of matter and antimatter, the two kinds of particles would have canceled each other out. But fortunately for us, there was a bit more matter than antimatter in the universe. Scientists hope that they'll be able to observe antimatter during LHC events. That might help us understand why there was a miniscule difference in the amount of matter versus antimatter when the universe began.
Dark matter might also play an important role in LHC research. Our current understanding of the universe suggests that the matter we can observe only accounts for about 4 percent of all the matter that must exist. When we look at the movement of galaxies and other celestial bodies, we see that their motions suggest there's much more matter in the universe than we can detect. Scientists named this undetectable material dark matter. Together, observable matter and dark matter could account for about 25 percent of the universe. The other three-quarters would come from a force called dark energy, a hypothetical energy that contributes to the expansion of the universe. Scientists hope that their experiments will either provide further evidence for the existence of dark matter and dark energy or provide evidence that could support an alternate theory.
That's just the tip of the particle physics iceberg, though. There are even more exotic and counterintuitive things the LHC might turn up. Like what?

LHC Research: The Strange Stuff

If theoretical particles, antimatter and dark energy aren't unusual enough, some scientists believe that the LHC could uncover evidence of other dimensions. We're used to living in a world of four dimensions -- three spatial dimensions and time. But some physicists theorize that there may be other dimensions we can't perceive. Some theories only make sense if there are several more dimensions in the universe. For example, one version of string theory requires the existence of no fewer than 11 dimensions.
String theorists hope the LHC will provide evidence to support their proposed model of the universe. String theory states that the fundamental building block of the universe isn't a particle, but a string. Strings can either be open ended or closed. They also can vibrate, similar to the way the strings on a guitar vibrate when plucked. Different vibrations make the strings appear to be different things. A string vibrating one way would appear as an electron. A different string vibrating another way would be a neutrino.
Some scientists have criticized string theory, saying that there's no evidence to support the theory itself. String theory incorporates gravity into the standard model -- something scientists can't do without an additional theory. It reconciles Einstein's theory of general relativity with the Quantum Field Theory. But there's still no proof these strings exist. They are far too small to observe and currently there's no way to test for them. That has lead to some scientists to dismiss string theory as more of a philosophy than a science.
­String theorists hope that the LHC will change critics' minds. They are looking for signs of supersymmetry. According to the standard model, every particle has an anti-particle. For example, the anti-particle for an electron (a particle with a negative charge) is a positron. Supersymmetry proposes that particles also have superpartners, which in turn have their own counterparts. That means every particle has three counter-particles. Although we've not seen any indication of these superpartners in nature, theorists hope that the LHC will prove they actually exist. Potentially, superparticles c­ould explain dark matter or help fit gravity into the overall standard model.
­How big is th­e LHC? How much power will it use? How much did it cost to build?

LHC by the Numbers

The Large Hadron Collider is a massive and powerful machine. It consists of eight sectors. Each sector is an arc bounded on each end by a section called an insertion. The LHC's circumference measures 27 kilometers (16.8 miles) around. The accelerator tubes and collision chambers are 100 meters (328 feet) underground. Scientists and engineers can access the service tunnel the machinery sits in by descending in elevators and stairways located at several points along the circumference of the LHC. CERN is building structures above ground where scientists can collect and analyze the data LHC generates.
The LHC uses magnets to steer beams of protons as they travel at 99.99 percent the speed of light. The magnets are very large, many weighing several tons. There are about 9,600 magnets in the LHC. The magnets are cooled to a chilly 1.9 degrees Kelvin (-271.25 Celsius or -456.25 Fahrenheit). That's colder than the vacuum of outer space.
Speaking of vacuums, the proton beams inside the LHC travel through pipes in what CERN calls an "ultra-high vacuum." The reason for creating such a vacuum is to avoid introducing particles the protons could collide with before they reach the proper collision points. Even a single molecule of gas could cause an experiment to fail.
There are six areas along the circumference of the LHC where engineers will be able to perform experiments. Think of each area as if it were a microscope with a digital camera. Some of these microscopes are huge -- the ATLAS experiment is a device that is 45 meters (147.6 feet) long, 25 meters (82 feet) tall and weighs 7,000 tons (5,443 metric tons) [source: ATLAS].
The LHC and the experiments connected to it contain about 150 million sensors. Those sensors will collect data and send it to various computing systems. According to CERN, the amount of data collected during experiments will be about 700 megabytes per second (MB/s). On a yearly basis, this means the LHC will gather about 15 petabytes of data. A petabyte is a million gigabytes. That much data could fill 100,000 DVDs [source: CERN].
It takes a lot of energy to run the LHC. CERN estimates that the annual power consumption for the collider will be about 800,000 megawatt hours (MWh). It could have been much higher, but the facility will not operate during the winter months. According to CERN, the price for all this energy will be a cool 19 million Euros. That's almost $30 million per year in electricity bills for a facility that cost more than $6 billion to build [source: CERN]!

LHC: Smashing Protons

The principle behind the LHC is pretty simple. First, you fire two beams of particles along two pathways, one going clockwise and the other going counterclockwise. You accelerate both beams to near the speed of light. Then, you direct both beams toward each other and watch what happens.
The equipment necessary to achieve that goal is far more complex. The LHC is just one part of the overall CERN particle accelerator facility. Before any protons or ions enter the LHC, they've already gone through a series of steps.

­Let's take a look at the life of a proton as it goes through the LHC process. First, scientists must strip electrons from hydrogen atoms to produce protons. Then, the protons enter the LINAC2, a machine that fires beams of protons into an accelerator called the PS Booster. These machines use devices called radio frequency cavities to accelerate the protons. The cavities contain a radio-frequency electric field that pushes the proton beams to higher speeds. Giant magnets produce the magnetic fields necessary to keep the proton beams on track. In car terms, think of the radio frequency cavities as an accelerator and the magnets as a steering wheel.

­Once a beam of protons reaches the right energy level, the PS Booster injects it into another accelerator called the Super Proton Synchotron (SPS). The beams continue to pick up speed. By now, beams have divided into bunches. Each bunch contains 1.1 x 1011 protons, and there are 2,808 bunches per beam [source: CERN]. The SPS injects beams into the LHC, with one beam traveling clockwise and the other going counterclockwise.

Inside the LHC, the beams continue to accelerate. This takes about 20 minutes. At top speed, the beams make 11,245 trips around the LHC every second. The two beams converge at one of the six detector sites positioned along the LHC. At that position, there will be 600 million collisions per second [source: CERN].

When two protons collide, they break apart into even smaller particles. That includes subatomic particles called quarks and a mitigating force called gluon. Quarks are very unstable and will decay in a fraction of a second. The detectors collect information by tracking the path of subatomic particles. Then the detectors send data to a grid of computer systems.

Not every proton will collide with another proton. Even with a machine as advanced as the LHC, it's impossible to direct beams of particles as small as protons so that every particle will collide with another one. Protons that fail to collide will continue in the beam to a beam dumping section. There, a section made of graphite will absorb the beam. The beam dumping sections are able to absorb beams if something goes wrong inside the LHC. To learn more about the mechanics behind particle accelerators, take a look at How Atom Smashers Work.