In July 2012, CERN announced that it detected a new particle, and suggested this might be Higgs Boson. More details of this announcement here
While it takes considerable power to run the Large Hadron Collider, the record-smashing energy generated by its collision events in 2009, according to Popular Mechanics, only corresponded to 3.78 × 10-7 J, a minuscule quantity of energy. A 100-watt light bulb left on for an hour, by comparison, consumes 360,000 J. Why is that? because despite the speed, a proton's mass is not very big.
The almost frictionless Quark-Gluon Plasma generated at the Hadron Collider, has reached temperatures in excess of several trillion degrees. However, the lifetime of the droplets of QGP produced in the laboratory is ultra short, a fraction of a second (In technical terms, only about 10-22 seconds). Click here for further details.
Click here for further background, at a fairly simple level.
Update below extracted from www.livescience.com
By Don Lincoln, Senior Scientist, Fermi National Accelerator Laboratory; Adjunct Professor of Physics, University of Notre Dame | August 28, 2018
If you've been a science fan for the last few years, you're aware of the exciting results to emerge from the Large Hadron Collider (LHC), which in 2012 found the Higgs boson, the subatomic particle responsible for giving mass to fundamental subatomic particles.
Today, physicists have another exciting announcement to add to the Higgs saga: They have made the first unambiguous observation of Higgs bosons decaying into a matter-antimatter pair of bottom quarks. Surprisingly, the Higgs bosons decay most often in this way.
The new announcement shows a strong agreement between the theoretical predictions and the experimental data, which could in turn set strict constraints on ideas of more fundamental physics that strive to explain why the Higgs boson even exists.
Field of dreams
In the 1960s, researchers were investigating linkages between the force of electromagnetism and the weak nuclear force, which is responsible for some types of radioactive decays. Although the two forces seemed distinct, it turned out that they both arose from a common and more fundamental force, now called the electroweak force.
However, there was a problem. The simplest manifestation of the theory predicted that all particles had zero mass. Even in the 1960s, physicists knew that subatomic particles had mass, so that was potentially a fatal flaw.
Several groups of scientists proposed a solution to this problem: A field permeates the universe, and it's called the Higgs field. Fundamental subatomic particles interacted with this field, and this interaction gave them their mass.
The existence of the field also implied the existence of a subatomic particle, called the Higgs boson, which was finally discovered in 2012 by researchers working at the European Organization for Nuclear Research(CERN) laboratory in Switzerland. (Disclosure: I am a collaborator on one of the research groups that made the initial discovery as well as today's announcement.) For their predictions of the Higgs field, British physicist Peter Higgs and Belgian physicist François Englert shared the 2013 Nobel Prize in physics.
Finding the bottom quarks
Higgs bosons are made in high-energy collisions between pairs of particles that have been accelerated to nearly the speed of light. These bosons don't live for very long — only about 10^minus 22 seconds. A particle with that lifetime, traveling at the speed of light, will decay long before it travels a distance the size of an atom. Thus, it is impossible to directly observe Higgs bosons. It is only possible to observe their decay products and use them to infer the properties of the parent boson.
Higgs bosons have a mass of 125 gigaelectron volts (GeV), or one that's about 133 times heavier than a proton.
To find the mass equivalent to an electron volt just convert eV to Joules and divide by c2.
1 electron volt = 1.60217646 x 10-19 joules, so 125 GeV is:
125 x 109 x 1.60217646 x 10-19 / c2 ≈ 2.22 x 10-25kg or 133 protons.
Calculations from well-established theory predicts that Higgs bosons decay into pairs of the following particles in the following percentages: bottom quarks (58 percent), W bosons (21 percent), Z bosons (6 percent), tau leptons (2.6 percent) and photons (0.2 percent). More exotic configurations make up the remainder. One of the key results of today's announcement was to verify that the prediction was correct for bottom quarks.
When physicists announced the discovery of the Higgs boson in 2012, they relied on its decay into Z bosons, W bosons and photons, but not bottom quarks. The reason is actually extremely simple: Those particular decays are far easier to identify.
At the collision energies available at the LHC, Higgs bosons are made in only one collision in every 1 billion. The vast number of collisions at the LHC occur through the interaction of the strong nuclear force, which is (by far) the strongest of the subatomic forces and is responsible for holding the nucleus of atoms together.
The problem is that in interactions involving the strong force, production of a matter-antimatter pair of bottom quarks is really quite common. Thus, the production of bottom quarks by Higgs bosons decaying into bottom quarks is totally swamped by pairs of bottom quarks made by more ordinary processes. Accordingly, it is essentially impossible to identify those events in which bottom quarks are produced through the decay of Higgs bosons. It's like trying to find a single diamond in a 50-gallon drum full of cubic zirconia.
Because it is difficult or impossible to isolate collisions in which Higgs bosons decay into bottom quarks, scientists needed another approach. So, researchers looked for a different class of events — collisions in which a Higgs boson was produced at the same time as a W or Z boson. Researchers call this class of collisions "associated production."
W and Z bosons are responsible for causing the weak nuclear force and they can decay in distinct and easily identifiable ways. Associated production occurs less often than nonassociated Higgs production, but the presence of W or Z bosons greatly enhances the ability of researchers to identify events containing a Higgs boson. The technique of associated production of a Higgs boson was pioneered at the Fermi National Accelerator Laboratory, located just outside Chicago. Because of the facility's lower-energy particle accelerator, the laboratory was never able to claim that it had discovered the Higgs boson, but its researchers' knowledge played a significant role in today's announcement.
The LHC accelerator hosts two large-particle physics detectors capable of observing Higgs bosons — the Compact Muon Solenoid (CMS) and A Toroidal LHC Apparatus (ATLAS). Today, both experimental collaborations announced the observation of the associated production of Higgs bosons, with the specific decay of Higgs bosons into a matter-antimatter pair of bottom quarks.
While the simple observation of this decay mode is a significant advance in scientific knowledge, it has a much more important result. It turns out that the Higgs field, proposed back in 1964, is not motivated by a more fundamental idea. It was simply added on to the Standard Model, which describes the behavior of subatomic particles, as something of a Band-Aid. (Before the Higgs field was proposed, the Standard Model predicted massless particles. After the Higgs field was included as an ad hoc addition to the Standard Model, particles now have mass.) Thus, it is very important to explore the predictions of decay probabilities to search for hints of a connection to an underlying theory. And there have been more recent and comprehensive theories developed since the 1960s, which predict that perhaps more than one type of Higgs boson exists.
Thus, it is crucial to understand the rate at which Higgs bosons decay into other particles and compare it with the predicted decay rates. The easiest way to illustrate agreement is to report the observed rate of decay, divided by the predicted rate. Better agreement between the two will yield a ratio close to 1. The CMS experiment finds excellent agreement in today's announcement, with a ratio of predicted-to-observed rates of 1.04 plus or minus 0.20, and the ATLAS measurement is similar (1.01 plus or minus 0.20). This impressive agreement is a triumph of current theory, although it does not indicate a direction toward a more fundamental origin for the Higgs phenomena.
The LHC will continue to operate through early December. Then it will pause operations for two years for refurbishing and upgrades. In the Spring of 2021, it will resume operations with considerably enhanced capabilities. The accelerator and detectors are expected to continue to take data through the mid-2030s and to record over 30 times more data than what's been recorded so far. With that increase of data and improved capabilities, it is quite possible that the Higgs boson still has stories to tell.
Originally published on Live Science.
Don Lincoln contributed this article to Live Science's Expert Voices: Op-Ed & Insights.
Elementary, dear God
Leigh Dayton, Science writer
Thursday, July 5, 2012
PHYSICIST Joe Incandela must see the irony. Like all his international colleagues, he'd promised to keep his group's findings a secret, saving the news for last night's live two-way seminar from Geneva and Melbourne. The plan was that as the world's scientific and media community waited breathlessly, Incandela would reveal that they'd confirmed the existence of the "God particle", the long-sought-after Higgs boson, the cornerstone of modern physics. But after successfully battling Melbourne — host of this week's International Conference on High Energy Physics — for the right of Geneva to share presentational glory, and keeping the twittersphere and blogosphere at bay for weeks, it was Incandela's own laboratory that blew it.
The European Organisation for Nuclear Research (known as CERN) yesterday posted — seriously prematurely — a brief video of him explaining that, yes, his team had found evidence the Higgs boson exists. "We've observed a new particle," Incandela announces on the video. "All this is very, very significant. It's something that may, in the end, be one of the biggest observations of any new phenomena in our field in the last 30 or 40 years." He adds that further work must be done to tease out all characteristics of the particle. "But we are very excited. I'm extremely tired at the moment, so I may not appear to be as excited as I really am, but the significance of this observation could be very, very great."
The tell-all video was quickly taken down by CERN, which downplayed the stuff-up, claiming the video was one of several, prerecorded to cover all possible findings: Higgs, no Higgs, and no meaningful result.
As Sydney University particle physicist Kevin Varvell notes, CERN takes credit for inventing the worldwide web. And the web, adds Geoff Taylor of Melbourne University, is a very democratic tool. "The issue of shutting people up is anathema to scientists," says Taylor, leader of the Australian contribution to the second Higgs discovery team, ATLAS. Both the CMS and ATLAS teams have about 3000 members from more than 100 nations. While Taylor acknowledges controlling scientists is like herding cats, he says the video leak could be accidental. "We'll wait and see."
Go back to the teams. Incandela heads the CMS (Compact Muon Solenoid) experiment, one of seven enormous particle detectors built on to the Large Hadron Collider at CERN near Geneva. It's the world's largest and highest-energy particle accelerator. The second team, ATLAS (A Toroidal LHC Apparatus), is headed by Fabiola Gianotti who, like Incandela, is Geneva-based.
It's been a long quest. The Higgs boson is an elementary particle first proposed in three papers in 1965, written separately by British physicist Peter Higgs, now 83, and two other teams. To this day Higgs says he's profoundly embarrassed that the particle was named after him. All six authors were honoured in 2010 with the J.J. Sakurai Prize for Theoretical Particle Physics, one of the most prestigious prizes in the field.
Now that their hypothetical particle is no longer hypothetical, bets are on that they're in line for the Nobel Prize. That's because the Higgs is the cornerstone of modern physics. It's the particle that endows other elementary particles — such as protons, neutrons, quarks and leptons — with mass, according to the Standard Model of physics that describes the interactions of all known subatomic particles and forces.
The Higgs was the only subatomic particle that hadn't been observed.
In the low-energy world of everyday life, mass is referred to as weight and is measured in units such as kilograms and pounds. In the high-energy world of physics, mass is defined as an object's resistance to acceleration, its inertia, its drag.
According to theory, in the beginning all particles were created equal. They all had the same mass and zipped about at the speed of light. But today, different subatomic particles clearly have different masses; otherwise, there would be no stars, planets, cats, dogs or particle physicists. Something produced that cosmic inequality and the Standard Model suggests that something is the Higgs field, an invisible energy field that switched on a trillionth of a second after the big bang blasted the universe into existence 13.75 billion years ago.
As Taylor explains, the Higgs is the "manifestation" of that field, as photons of light are the manifestation of the electromagnetic field. That's why both photons and the Higgs are known as bosons, or carriers. "The field is everywhere," he says, eerily echoing Zen masters and Jedi knights. The Higgs does its mass-imparting job, explains Taylor, in much the way water slows down swimmers. "Subatomic particles feel the effect of the field like bodies moving through water. They gain mass, inertia." The more a particle "feels" the field, the heaver it becomes.
The discovery of the Higgs boson is near-proof that the universal field exists and thus lends, well, weight to the Standard Model. Cosmologists and physicists can now probe the earliest moments of existence, confident they have a reliable intellectual tool to do so, despite a few intriguing inconsistencies. For instance, some subatomic particles, such as photons, pass through the field untouched.
Little wonder the Higgs is called the God particle. Or as Arizona State University cosmologist Paul Davies calls it, the "goddamn particle" because, until now, it had failed to turn up. Getting the goddamn particle to show its spots involved creating subatomic particle collisions. That was the job of the Large Hadron Collider. Built at a cost of $10 billion between 1998 and 2008, it lies beneath the Franco-Swiss border, in a tunnel 27km in circumference, as deep as 175m. It hurtles beams of subatomic particles — part of the nuclei of atoms — into one another at phenomenally high speed.
It was built with the co-operation of more than 10,000 scientists and engineers from 100-plus countries, as well as hundreds of universities and laboratories. "One of the wonders is that it works, given all the different groups, nations and personalities," says Varvell, who rates it as one of the most successful scientific endeavours of all time.
The Australian understands that is the main reason CERN heavied organisers of the Melbourne conference, chaired by Taylor, insisting that Incandela and Gianotti deliver their findings from Geneva. In rough economic times, success and glory are as precious to national funding as the Higgs boson is to particle physicists. Given the spectacular success of the LHC, there's little likelihood that nations will withdraw their support, as rumoured in recent months. Australia's contribution to the $1 billion annual operating cost is a modest $150,000 a year, well below concern to budget-conscious Labor or Coalition razor gangs.
From Geneva, CERN director-general Rolf Heuer claims that over its nearly 60 years of existence the organisation has weathered many financial storms. "I can't predict the future, but I can say that our member states approved the lab's 2013 budget at (this month's) meeting of the CERN council," he tells The Australian.
Balancing prestige and scientific loose lips with the need to ensure members of both teams were happy with their group's final announcement was always going to be difficult. As with any important scientific finding, results released prematurely can lead to error. "It also looks bad for science," says Taylor. "We don't want to be thrashing about with rumours, though in this case it was more than rumours."
Still, the rumour mill had edged in on the facts before the premature posting of the Incandela video. The Higgs boson not only has its own hashtag, #HiggsRumours, it recently topped the list of trending Twitter topics. Social media mentions reached fever pitch last week, much of the content predicting what Incandela revealed, though it wasn't confirmed until last night that the same evidence had been found by the ATLAS team.
After the LHC created Higgs bosons — which blink out of existence immediately after they're created — both experiments found that the subatomic particles decayed in the same two of many ways predicted by the Standard Model.
The other predicted modes of decay must now be tracked to confirm that physicists have truly found the God particle and not a god-like particle. It's vital that there be no suggestion that the findings are statistical aberrations or evidence of a new type of Higgs, for instance, one predicted by another explanatory model such as supersymmetry. While an alternative Higgs boson would not invalidate observations based on the Standard Model, it could be "really exciting" for physicists, says Varvell. "We would be back to square one."
That's why Incandela was careful to stress that there's more work to be done. It will involve scouring the data already produced and generating more collisions for study. "What we've looked for is a few grains on a beach," says Incandela. "I did some calculations, and if you replaced every event, every collision of the (particle) beams that we've scanned or had taken place in our experiment over the past two years, if you let each of those be represented by a grain of sand, you'd have enough sand to fill an Olympic-sized swimming pool. "And the number of events that we've collected that we claim represent this observation are in the order of tens, or dozens." Still, he predicts the finding will hold. "It could be a gateway … to the next phase of exploring the deepest fabric of the universe, which is pretty profound when you think about it."
And that's just what scientists worldwide are doing right now.
The how of our existence, and maybe the why
Adam Spencer is the Breakfast host on ABC radio's Sydney 702. He has a first-class degree in pure mathematics.
THIS is really exciting. Not just for my geeky brothers and sisters at the CERN Laboratory. Not just for the army of 40-year-olds who, like me, last experienced this sort of all-consuming, deeply cerebral buzz when we first broke the one-minute mark for solving a Rubik's Cube (personal best: 41 seconds — hello ladies!). No, today is a great day for all of humanity.
We have found the Higgs boson. It seems we may have answered the decades-old question of how fundamental particles actually have mass. It's a question so deep that to even ask it was once considered audacious, to answer it impossible. But indeed it seems we have answered it. Photons (particles of light) do not have mass, most subatomic particles do. But it's one thing to know things have mass, it's another thing to know why things have mass. Peter Higgs and friends guessed that the universe was full of this invisible sticky sea (the Higgs field) of particles (Higgs bosons) that attached to almost all other particles giving them mass.
The applications could be amazing. Perhaps one day we could remove mass from objects, transport them weightlessly at the speed of light over fantastic distances, then "re-mass" them on their arrival across the other side of the cosmos. We may construct a theory of everything that unlocks higher dimensions and parallel universes. Dark matter and other mysteries may soon confuse us no more.
But for me today is just a day to sit back and be happy with what we have. To think that 50 years ago the brightest human minds could have postulated an answer to the deepest of all possible problems and that five decades later we would have had the technological nous to re-create conditions similar to the big bang that gave birth to our universe, and that these two things combined would give us a giant, once-in-a-lifetime leap forward in understanding "how it all works" — wow, I'll take that.
It's been a good day.
** End of article