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
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.
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…

80 thoughts on “What is the Higgs Boson?”

  1. Nice piece Ian! I think I’ll struggle to find a better-executed piece about the Higgs.

    I worked at Fermilab over the summer few years back, so I’m super, duper, extra excited to see the LHC go live 🙂

  2. “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.”

    I heard the cost was 8 billion. I forget the currency, it’s not that important. It either means you can’t wage war in Iraq for four weeks or for six for the cost of this device.

    8 billion for a scientific experiment of this magnitude is chump change. I gladly contribute to it. At least we’re going to learn something.

    8 billion, when the next US defense discretionary budget is about 540 billion dollars for ’09. And that’s not counting the war in Iraq and Afghanistan. 8 billion wouldn’t cover the coffee bill for the people who have to find back 2 trillion dollars in the Pentagon’s books of which nobody has an idea [that they will admit to] of what it was spent on.

    Compared to US defense spending, the LHC is like a marketing gimmick, a keyring to commemmorate a sales convention.

    It’s the next price point up from being free.

  3. I am sure that this comment will be removed, but I cannot resist posting it.

    First, who am I? I am a science and space junkie. I used to get “Things of Science” in the mail in the 60’s when I was 8 years old.

    But I worry. I worry about what we do not know. I worry that what we do not know will hurt us. I worry that we may create black holes with low velocity with respect to the Earth that may, for some unknown reason, not disappear very quickly.

    It’s one thing to experiment and have it fail. It’s another if it has an actual, albeit low (according to scientists of 2008) chance of destroying the Earth.

    What is the rush? Can we not theorize for another decade or two, examine old particle tracks and think a little more about it? Not as exciting, perhaps, and careers don’t advance so fast. Is this a reason to rush?

  4. John Smith. I don’t know if this will make you feel any better, but these same concerns were raised when the Relativistic Heavy Ion Collider on Long Island was created. We are still here many years after the creation of RHIC.

  5. Since we know mass increases as speed approaches c, would it be possible to then manipulate this based on understanding how the Higgs field works from these experiments? Could we then shed mass as it would be accumulating while particles flow through the field attracting mass, since we would have a fundamental understanding of this physical process and how to deviate it? I picture a balloon filling up with air (assume a process we have no control over, i.e. particle is acquiring mass as it passes through the field), and by creating a hole in the balloon to drain air as it is filling up (manipulation of particle/field behaviors), we can keep the balloon from expanding. Does this LHC experimentation lead us in the long run to travel at c, and even manipulating gravity on a subatomic level?

  6. Would you like to check the LHC site and correct the intro?
    Initial proton energies are to be restricted to 5TeV – eventually 7TeV per / 14TeV collision. And much higher for lead ions.

  7. Hi Jon.

    You are totally right. Grabbed the info from the LHC factsheet, but I obviously mis-read it somewhere. Thanks for pointing that out! Edited now 🙂

    Cheers, Ian

  8. i’ve been following stories on this for the last year and cant wait for it to be switched on. take a look at the pictures and the actual complexity of the machine being built. i detest people who protest against this sort of thing and actually reminds me of the small minded people back in history who held back science from developing into the field it has now. who knows what new discoveries could be made and we won’t know without taking a few risks. roll on september 10th!

  9. Nice one Ian.
    I should have also said (I was feeling a bit grumpy at the time!) that it’s a very nice article: the LHC is fantastic science and has, so far, received very little popular attention, (apart from silly-season stuff).
    After this weekend’s first injection from SPS to the LHC, http://lhc-injection-test.web.cern.ch/lhc-injection-test/planning/inj-test-schedule.htm , it’s getting very exciting.
    For anyone with an interest, I recommend the FAQ as a good general introduction http://cdsweb.cern.ch/record/1092437/files/CERN-Brochure-2008-001-Eng.pdf .

    All the best
    Jon.

  10. Hey – soz, I was a bit grumpy or I would also have added “nice article”.
    The LHC is the most fantastic science experiment ever and, apart from the nonsense “end of world” stuff, gets little popular coverage so… more power to you mate!

  11. “LHC blows up world! Humans reckless with dangerous technology” says the headlines of the Martian Times. Does anyone really believe that the LHC will destroy the earth? More likely that it will destroy the careers of physicists whose hypotheses or theories are not supported. Besides, if it does blow us up, we won’t know it happened. And the data will be very interesting.

  12. headline:

    LHC creates supermassive blackhole. bit torrent speeds increase 2 million fold. flying cars now a reality. sale of space junk and mars/venus rovers take off as home shopping network sees spike in speculative interest. in other news, the federal reserve held interest rates steady at 0.0001% while inflation (excluding food, energy, housing, clean water, and nuclear missles) held steady at 4%. physicists baffled by loss of pension funds, asks state for more money. taxpayers rejoice. dow jones headed for best start since 1995. new record territory as home starts increase 200 fold. ceo pay now a paltry 2000 times the average workers living wage. grandola systems ipo’s at a first ever $10 trillion market capitalization, specializing in organic strawberry desserts targeted especially to the growing fiberoptics engineer community. grandola systems is located in a gated community in the east most sector of I-280 2000 meters away from suburban downtown where les miserables in 3d is playing at imax. buy your tickets now at ticketmaster or by phone. see you soon!

  13. Remember when we tried to warn everyone about the END OF THE WORLD due to the Y2K bug? Nobody listened, and sure enough the world ended and we all died. I’m not going through THAT again.

  14. Disciple:

    Dude, I was pissed!! I was so close to making out with the hottest blonde ever at the party but then at midnight, bang!

  15. You are talking about HIGGS-BOSON without explaining what is BOSON. Higgs did only an extension of Bose’s theory. But Bose’s name is erased out , because Higgs is British but Bose is Indian. Bose ( S.N.Bose not to be confused with J.C.Bose who invented radio transmission a few years before Marconi or A.N.Bose of Bose Hi-Fi)could not get any Noble Prize, but those Anglo-Americans who did extensions on Bose’s theory got Noble Prize. Bose’s theory was not published in any Anglo-American journals, they all rejected it. At the end Einstein translated it and published it in a German journal. It shows the Anglo-American racism even in Physics.

  16. Hi Moron. I didn’t explain what a boson was as I didn’t want to give a lecture on all aspects of particle theory. Physicists are acutely aware of who bosons are named after – it was taught to me in my first course in particle physics as an undergrad. Yes, it is unfortunate about the Nobel Prize, and I’m uncertain about the details, but I doubt it has anything to do with Anglo-American racism.

    1. Hello Mr. O’Neill, although you cited the reason that you didn’t want to give a lecture on ‘all aspects of particle theory’ for not writing a word on Prof. Bose, you may agree it’s not entirely fair. We are not talking about ‘all aspects of particle theory’, it’s about the very particle your article is about which is named after him. This general denial of mentioning his contribution indeed is unexplainable. 

  17. So, let’s say that the elusive Higgs boson is discovered. Then what? Will it fuel a single auto? Will it feed a single mouth? While I applaud the science involved, precisely what is expected from this?

    In my opinion, a more worthy field of study would be gravity. Until we are able to fully understand gravity, and eventually recreate it in some usable fashion, space travel will be restricted to our humble satellite, the moon.

    After this, the next field of study should be the return to the atomic engine. Far more efficient and effective than chemical engines.

  18. I worry about what we do not know. I worry that what we do not know will hurt us. I worry that we may create black holes with low velocity with respect to the Earth that may, for some unknown reason, not disappear very quickly.

  19. There is probably no such thing as a Higgs (hickup) field, the field, the only one in existence is the field of consciousness (the indian Rishis called it Chitta) and we by witnessing and painting our ideas into it shape reality. Or as quantum physics have proven, the wish or anticipated outcome of the experimenter changes what is being observed. Or as zen master puts it after meditating for 20 year and being asked what we/he is? “We are the white wall (matrix/whichisatorroidialdonutintheheart) where we project out lives onto”. If that can be put into a formula I am not sure ~:) But maybe what the guys are seeking is just to complicated/still misguided by the wrong mindset. And as all truth is simple, maybe their real intention is just trying to find some new super weapon or create artificial wormholes for the governments/realforcesbehindthem. Since when did science get money without any 'practical' application? I leave you with this: http://www.goldenmean.info/goldenproof/

  20. I predict that the L.H.C is, in fact, the most expensive piece of junk ever created, and it will never produce valuable results because there are more problems yet to occur with this machine. The quality of workmanship involved in its construction and assembly were very poor. In the future there will be a great reluctance to fund such large scale scientific projects, and when people ask why, they will be reminded of the disaster that was the Large Hadron Collider. The long fabled collision of particles, will never in fact take place at all, with the L.H.C.

  21. I dont got to know/understand why the Higgs itself has to have mass, even more, of this or that amount. Can you explain this, please?

  22. I dont got to know/understand why the Higgs itself has to have mass, even more, of this or that amount. Can you explain this, please?

  23. What is God Particle? According my fresh thought:1. It is a naked singularity of mass or the smallest black hole in the Universe; 2. It has huge naked mass, gravitation and inertia;3. It is not a material particle;4. It is not in the Standard Model of elementary particles;5. It is an Ultimate Particle, cannot be decay;6. Its Mass cannot be converted into energy; 7. The lowest limit of its mass is about 10.9μg, and the upper limit is about 0.67*10^6kg, that means that its mass may be exceeded one kilogram! 8. Estimated mass of Higgs Particle is about 16 orders of magnitude smaller than lower limit of Mass of God Particle at least. So the mass of God Particle is substantially undervalued by mainstream physics9. So Higgs particle is not God particle;10. And so I believe that to find the God particle with LHC is an impossible mission, LHC efforts will be ended in failure, and it is destined. I think that to find God Particle with colliders (such as LHC) is an extremely extravagant wrong way. How to find God Particle?Based on my bran-new thread, I design several kinds of very simple and very cheap physical experimental methods to find the God particle, to make a small black hole and to create new unknown stable material particles without using any accelerator or collider such as LHC. Maybe to find God Particle is not a hard mission for me?Revolution in Physics will soon arrival, believe me.

  24. Are pleased to re-visit your blog, from which I learned a lot of knowledge, and totally agree with your point of view, I hope you can be the exhibitions, once again thank you for sharing such a wonderful text. I will wait to see what's! Thank you!i love golf umbrella very much .

  25. I am sure that this comment will be removed, but I cannot resist posting it.First, who am I? I am a science and space junkie. I used to get “Things of Science” in the mail in the 60's when I was 8 years old.But I worry. I worry about what we do not know. I worry that what we do not know will hurt us. I worry that we may create black holes with low velocity with respect to the Earth that may, for some unknown reason, not disappear very quickly.It's one thing to experiment and have it fail. It's another if it has an actual, albeit low (according to scientists of 2008) chance of destroying the Earth.What is the rush? Can we not theorize for another decade or two, examine old particle tracks and think a little more about it? Not as exciting, perhaps, and careers don't advance so fast. Is this a reason to rush?kamagra acne

  26. Nice piece Ian! I think I'll struggle to find a better-executed piece about the Higgs.I worked at Fermilab over the summer few years back, so I'm super, duper, extra excited to see the LHC go live 🙂

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