What is the Higgs Boson?

Artist rendition of Higgs bosons generated after a particle collision. Created for Niels Bohr institute by artist-in-residence Mette Høst

Billions of Euros have been ploughed into the construction of the largest experiment known in the history of mankind. The Large Hadron Collider (officially due to be “switched on” September 10th 2008) will eventually create proton-proton collision energies near the 14 TeV mark by the end of this decade. This is all highly impressive; already the applications of the LHC appear to be endless, probing smaller and smaller scales with bigger and bigger energies. But how did the LHC secure all that funding? After all, the most expensive piece of lab equipment must be built with a purpose? Although the aims are varied and far-reaching, the LHC has one key task to achieve: Discover the Higgs Boson, the world’s most sought-after particle. If discovered, key theories in particle physics and quantum dynamics will be proven. If it isn’t found by the LHC, perhaps our theories are wrong, and our view of the Universe needs to be revolutionized… or the LHC needs to be more powerful.

Either way, the LHC will revolutionize all facets of physics. But what is the Higgs boson? And why in the hell is it so important?

I’ve read many very interesting articles about the Higgs boson and what its discovery will do for mankind. However, many of these texts are very hard to understand by non-specialists, particularly by the guys-at-the-top (i.e. the politicians who approve vast amounts of funding for physics experiments). The LHC physicists obviously did a very good job on Europe’s leaders so this gargantuan particle accelerator could secure billions of euros/dollars/pounds to be built.

There is a classic physics-politics outreach example that has become synonymous with LHC funding. On trying to acquire UK funding for the LHC project in 1993, physicists had to derive a way of explaining what the Higgs boson was to the UK Science Minister, William Waldegrave. This quasi-political example is wonderfully described by David J. Miller; Bryan Cox also discusses the same occasion in this outstanding TED lecture.

What is the Higgs boson? The Short Answer
Predicted by the Standard Model of particle physics, the Higgs boson is a particle that carries the Higgs field. The Higgs field is theorized to permeate through the entire Universe. As a massless particle passes through the Higgs field, it accumulates it, and the particle gains mass. Therefore, should the Higgs boson be discovered, we’ll know why matter has mass.

What is the Higgs boson? The Long Answer
Firstly we must know what the “Standard Model” is. In quantum physics, there are basically six types of quarks, six types of leptons (all 12 are collectively known as “fermions”) and four bosons. Quarks are the building blocks of all hadrons in the Universe (they are contained inside common hadrons like protons and neutrons) and they can never exist as a single entity in nature. The “glue” that holds hadrons together (thus bonding quarks together) is governed by the “strong force,” a powerful force which acts over very small distances (nucleon-scales). The strong force is delivered by one of the four bosons called the “gluon.” When two quarks combine to form a hadron, the resulting particle is called a “meson“; when three combine, the resulting particle is called a “baryon.”

The Standard Model. Including 6 quarks, 6 leptons and four bosons. Source: <a href='http://commons.wikimedia.org/wiki/User:MissMJ'>http://tinyurl.com/6z3tb3</a>

The Standard Model. Including 6 quarks, 6 leptons and four bosons. Source: http://tinyurl.com/6z3tb3

In addition to six quarks in the Standard Model, we have six leptons. The electron, muon and tau particles plus their neutrinos; the electron neutrino, muon neutrino and tau neutrino. Add to this the four bosons: photon (electromagnetic force), W and Z bosons (weak force) and gluons (strong force), we have all the components of the Standard Model.

However, there’s something missing. What about gravity? Although very weak on quantum scales, this fundamental force cannot be explained by the Standard Model. The gravitational force is mediated by the hypothetical particle, the graviton.

The Higgs Field
The Standard Model has its shortcomings (such as the non-inclusion of the graviton) but ultimately it has elegantly described many fundamental properties of the quantum and cosmological universe. However, we need to find a way of describing how these Standard Model particles have (and indeed, have no) mass.

Permeating through all the theoretical calculations of the Standard Model is the “Higgs field.” It is predicted to exist, giving quarks and gluons their large masses; but also giving photons and neutrinos little or no mass. The Higgs field forms the basic underlying structure of the Universe; it has to, otherwise “mass” would not exist (if the Universe is indeed governed by the Standard Model).

People evenly distributed in a room, akin to the Higgs field (CERN)

People evenly distributed in a room, akin to the Higgs field (CERN)

As a particle travels through the Higgs field (which can be thought of as a 3D lattice filling the Universe, from the vacuum of space to the centre of stars), it causes a distortion in the field. As it moves, the particle will cause the Higgs field to cluster around the particle. The more clustering there is, the more mass the particle will accumulate. Going back to David J. Miller’s 1993 quasi-political description of the Higgs field, his analogy of the number of people attracted to a powerful politician rings very similar to what actually happens in the Higgs field as a particle passes through it (see the cartoon left and below).

Using the cartoon of Margaret Thatcher, ex-UK Prime Minister, entering a crowded room, suddenly makes sense. As Thatcher enters the room, although the people are evenly distributed across the floor, Thatcher will soon start accumulating delegates wanting to talk to her as she tries to walk. This effect is seen all the time when paparazzi accumulate around a celebrity here in Los Angeles; the longer the celeb walks within the “paparazzi field,” more photographers and reporters accumulate.

Then Thatcher enters the room, people gather, mass increases (CERN)

Then Thatcher enters the room, people gather, mass increases (CERN)

Pretty obvious so far. The Thatcher analogy worked really well in 1993 and the paparazzi analogy works well today. But, critically, what happens when the individual accumulates all these people (i.e. increase mass)? If they are able to travel at the same speed across the room, the whole ensemble will have greater momentum, thus will be harder to slow down.

The Higgs Boson
So going back to our otherwise massless particle travelling through the Higgs field, as it does so, it distorts the surrounding field, causing it to bunch up around the particle, thus giving it mass and therefore momentum. Observations of the weak force (exchanged by the W and Z particles) cannot be explained without the inclusion of the Higgs field.

OK, so we have a “Higgs field,” where does the “Higgs boson” come into it? The Higgs particle is simply the boson that carries the Higgs field. So if we were to dissect a particle (like colliding it inside a particle accelerator), we’d see a Higgs boson carrying the Higgs field. This boson can be called a Higgs particle. If the Higgs particle is just an enhancement in the Higgs field, there could be many different “types” of Higgs particles, of varying energies.

British particle physicist Peter Higgs (as seen in the 1960s), Higgs boson namesake and lead researcher on the Higgs mechanism (Peter Tuffy)

British particle physicist Peter Higgs (as seen in the 1960s), Higgs boson namesake and lead researcher on the Higgs mechanism (Peter Tuffy)

This is where the LHC comes in. We know that the Higgs boson governs the amount of mass a particle can have. It is therefore by definition “massive.” The more massive a particle, the more energy it has (i.e. E = mc2), so in an effort to isolate the Higgs particle, we need a highly energetic collision. Previous particle accelerator experiments have not turned up evidence for the Higgs boson, but this null result sets a lower limit on the mass of the Higgs boson. This currently holds at a rest-mass energy of 114 GeV (meaning the lower limit for the Higgs boson will be greater than 114 GeV). It is hoped that the high energy collisions possible by the LHC will confirm that the Higgs exists at higher masses (predicted in the mass range of 0.1-1 TeV).

So why is the Higgs boson important?
The Higgs boson is the last remaining particle of the Standard Model that has not been observed; all the other fermions and bosons have been proven to exist through experiment. If the LHC does focus enough energy to generate an observable Higgs boson with a mass over 114 GeV, the Standard Model will be complete and we’ll know why matter has mass. Then we will be working on validating the possibility of supersymmetry and string theory… but we’ll leave that for another day…

But does the Higgs boson give hadrons the ability to feel pain? I doubt it…

Special thanks to regular Astroengine reader Hannah from São Paulo, Brazil for suggesting this article, I hope it went to some way of explaining the general nature of the Higgs boson…

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80 responses to “What is the Higgs Boson?

  1. THE UNIVERSE AS ILLUSION Let's define speed of distribution of gravitation. Two bodies are drawn with any force and to change her it is possible only change of distance between them – i.e. having displaced one of bodies – we shall cause change of force that will lead to to displacement of the second body, or, otherwise, displacing the first body – we create a gravitational wave, observing displacement of the second body – is registered her. However to change position of a body it is possible only with the help of the third body, changing simultaneously and his position – two gravitational waves compensating each other are created. Unique observable effect – resistance of a body to attempts to change his position.Let's consider our attempts a little differently. Gravitational interaction is carried out on the lines connecting the centers of weights, – let it there will be gravitational strings. What properties of them to give? We shall displace a body, from set of gravitational strings we shall choose two, strictly forward and back on a direction of movement. The first will be compressed, the second two zones – compression and under pressures will be stretched, will be dragged out, formed, and everyone aspires to return a body in an initial point. Having displaced a body, it is necessary to keep it while waves of compression and under pressure will not disperse on all length gravitational strings. But in the infinite flat universe it gives nothing – at any final speed of gravitation time of deduction indefinitely. We shall close the universe. Waves of compression and under pressure will swallow up each other, there is time of deduction – time of movement of a wave on a circle. Let time of movement a zero. Then the inert weight is instant gravitational reaction of the closed universe.Einstein has proved it more elegantly. If gravitation is a curvature of space the infinite straight line is closed – moving on by her, we shall return to an initial point. But to return to an initial point it is possible only during initial time, duration of such movement is equal to zero, speed is higher light and has forbidden the proof. Simply on has overlooked – to divide on a zero is impossible and instantly – is not faster, it is incommensurable with C.Idea of Newton, principle of the Mach, Einstein's proof – all for a long time is known, however some consequences can represent insignificant interest. So: The inert weight is instant gravitational reaction of the closed universeBut if the space is closed, time also is closedBut then the universe has no neither the beginnings, nor the endBut then time of life U. is equal to zeroBut then at U. infinite set of livesBut then they are not necessarily identicalBut then at everyone the set of interactionsBut then, probably, there is even one set of interactions closing space and time in infinityAnd all this simultaneously, i.e. develops.But then begins cinema – if the infinite set is virtual-lethal U. in the sum is given by a zero, infinite set identical, is virtual-immortal U., being imposed, create illusion real U.Illusion – any attempt to specify the microcosm device gives return result for on the one hand reduces density real U., and with another does visible reduction process to zero of the sum virtual, there are the interactions which do not have any rights on The fine idea of knowledge of the world generates phantoms – and what with them now to make? It is curious, that spatial isolation is reflected by an equivalence principle, time isolation – an uncertainty principle, both naked fixing – the devil only knows why, but heavy and inert weights are completely not casually equal, and any attempt to specify device V yields strictly return result. Artificiality both is obvious – whether their further presence is justified?Detecting of gravitational waves not a problem – longitudinal waves create inert weight, cross-section – electromagnetic radiation, the third variant – electro-gravitational waves is presented unevidently that is why it is not known. Small misunderstanding, not noteworthy.

  2. Thanks a lot! I am just learning Information of Subject.Php and this was very easy to follow and helped a lot.You really took time to explain every little bit.Thanks again.

  3. Thanks a lot! I am just learning Information of Subject.Php and this was very easy to follow and helped a lot.You really took time to explain every little bit.Thanks again…

  4. This is a great leap in science. I think there are more inventions and researches that are widely been tried and some are still studied but when it is done it generates the needed outcome. I am awed by this one here. Would love to see some updates too.

  5. A great scientific venture on the big leap on science! This is amazing! I am very happy to know this discovery! I do hope the people on this project set their mind for the benefit of science.

  6. When you get on the scale in the morning, you may be hoping that it registers a smaller number than the day before — you may be hoping that you’ve lost weight. It’s the quantity of mass in you, plus the force of gravity, that determines your weight.Solar Generator

  7. I know this may sound like an ignorant question, but what gain will this provide to man kind? Will it help us develop a fuel to make space travel over long distances feasible? Can this research explain why my dog runs into walls, seemingly on purpose? I don’t mean to down-play the importance of the higgs boson, but I just don’t see the purpose of spending all this time, money, and effort to answer a question, just to answer a question. What is the pay off?

  8. Yemek Tarifleri Thanks for this post – I have struggled with this as I have NO comments yet on my blog and in some ways feel badly about that (until i read your posts about this) and yet I see there is more that I can do. thankss.

  9. I am a layman with interest.  Your article is fantastic for those who are wondering and the description understandable by the masses.(pun intended :)  )

  10. WHY DOES MATTER HAVE MASS?  WIRELESS ENERGY DEMANDS  MATTER TO CREATE  MASS  TO BEGIN  UNIVERSE TO KEEP SMOOTH AND IN EQUILIBRIUM FOR MAN TO KEEP  PHYSICALY AND MENTALLY ALERT AND ALL LIVE TO GROW, LIVE AND DIE  TO PROCREATE ON  FOREVER!  

  11. WHAT GAIN TO MANKIND? TO ENJOY GOODNESS AND LOVE: TO GROW FLOWERS AND TREES FOR OXYGEN: TO USE BRAINS TO CREATE NEW IDEAS FOR  JOY AND SURVIVAL: TO LEARN HOW TO DISCOVER FUTURE OF COSMO:  WHAT MANKINDS DESTINY WILL BECOME! NOT TO MENTION HOW MAN WILL WORK TO LIVE LONGER, CURE DISEASES ESPECIALLY CANCER(WHICH I HAVE ALONG WITH DAUGHTER HAS BREAST CANCER, SISTER DIED WITH LIVER CANCE) !  SO MUCH STILL UNDONE, YET!  YOU  DON’T KNOW WHAT GAIN  CREATION IS FOR MANKIND?  DO SOME MORE THINKING WITH YOUR GREAT MIND WHICH YOU BARELY HAVE USED–AS YET! 

  12. Article is very good, but I am still not getting a handle on the Higgs particle.  What determines the mass of a Higgs particle?  A super higgs field?  And what determines the mass of that field’s associated boson?    Also, what is the differing nature of particles that they would attract more or less of the Higgs field unto itself, thereby increasing its mass? 

  13.  Well with 13 democrats facing probes, you wonder what’s new? That
    seems to always be the case. Then again, both sides usually find
    themselves in hot water at some point or another. Thanks for the update.

  14. @Dave,

    What a truly asanine, head-in-the-sand comment. Scientific expendature has absolutely no tie-in to GNP/GDP. They are through donation and taxation (Federal grant or endowment) and have NO basis in the Constitution, that quirkly little document that establishes our Nation.

    Miltary expendature, on the other hand, is a requirement for the security of a nation and her allies. Without this effort, all of the scientific knowledge is for naught.

    As for your anecdote regarding lost monies, the funds were spent. Though the answer for where they went might not fit into your defnition of ‘found’, trust me, the money was spent. We in the military are held quite accountable for where and when money is spent. The ones who are not held accountable are the ones who authorize money to be spent, namely Congress.

    Defense spending is crucial to the survival of a nation, the LHC is not.

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