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Not so deific particle – Higgs boson

In a May 5, 2017, article Space.com‘s Spaceman1 discusses why there’s much ado about the Higgs boson.

Let’s be perfectly honest. The Higgs boson and its role in the universe are not the easiest things to explain. It doesn’t help that the Higgs has the horrible nickname of “the God Particle” and is often described as being “responsible for mass in the universe” or something like that.

The Higgs boson is indeed an important part of modern physics, but elevating it to the status of a deity seems a bit of a stretch, and the whole “making mass” thing isn’t even this particle’s most important job.

Sometimes using words that admittedly are in lieu of better ones, he explains:

At high temperatures, the four carries of the electroweak force do their thing (carry the electroweak force) and the four higglets do their thing (not much of anything). But at low temperatures, the higglets get disrupted. Three of them “glue” … to three of the electroweak carriers. … and, voilà, the weak force is born.

But the fourth higglet gets “stuck” … in an asymmetrical state that prevents it from matching up with the remaining electroweak carrier. … and, aha, you get the photon, carrying the now-familiar electromagnetic force.

That fourth “stuck” higglet is left all alone, and that particle is what scientists mean when they say they’re looking for the Higgs boson. By searching for that particle, and hence learning about its associated field, researchers can get a better understanding … why the weak nuclear force is fundamentally different from the electromagnetic force.

His article contains an image of a “Simulation of a particle collision in which a Higgs boson is produced,”  a March 23, 2017, YouTube video2 on the subject, and an interesting video analogizing the Higgs field to a snowy landscape – an infinite flat field of snow – and different modes of crossing (interacting with) that snow.

Update June 2020

As to the question of what the Higgs field and the Higgs boson is all about, YouTube videos by Fermilab’s Don Lincoln are helpful, especially for analogies.

YouTube > Fermilab > “Subatomic Stories: The amazing Higgs boson” – Don Lincoln (May 27, 2020).

The Standard Model of particle physics was devised in the 1960s and 1970s and tested extensively over the decades. However, there was one question that was unanswered and that is the origin of the mass of subatomic particles. A theory proposed in 1964 by Peter Higgs and others attempted to answer that question. The theory proposed an energy field called the Higgs field and a particle called the Higgs boson. It took nearly fifty years, but in 2012, the Higgs boson was discovered. In episode 8 of Subatomic Stories, Fermilab’s Dr. Don Lincoln sheds some light on this last discovered feature of the Standard Model.

YouTube > Fermilab > “What is a Higgs Boson?” (Don Lincoln) – One explanation of the Higgs field (July 7, 2011).

YouTube > TED-Ed > “The Higgs Field, explained – Don Lincoln” – Second explanation of the Higgs field (August 27, 2013).

(Explanation #1 transcript quote) In 1964 a physicist by the name of Peter Higgs took some ideas that were floating around at the time, added an insight or two of his own, and proposed that there was an energy field that permeated the entire universe. This energy field is now called the “Higgs field.”

The reason he proposed this field was that nobody understood why some subatomic particles had a great deal of mass while others had little and some had none at all! The energy field that Higgs proposed would interact with the sub-atomic particles and give them their mass. Very massive particles would interact a lot of the field while massless particles wouldn’t interact at all.

To better understand the idea, we can use the analogy of water and swimmers. In our analogy the water serves the role of the Higgs field. A barracuda, being supremely streamlined, interacts only slightly with the field and can move through it very easily. The barracuda would then be similar to a low-mass particle.

In contrast, my buddy Eddie, no stranger to doughnuts, can only move very slowly through the water. In our analogy, Eddie is a massive particle made massive by interacting a lot with the water.

The lightest of the familiar subatomic particles is the electron, while in the subatomic world the king of mass is the top quark. It weighs about as much as an entire atom of gold, about three hundred and fifty thousand times more than the electron!

I’d like to stress that we believe the top quark is not more massive because it’s bigger. It’s not! In fact, we believe that both the top quark and the electron are exactly the same size! Indeed, they both have zero size! The top quark is more massive than the electron simply because it interacts more with the Higgs field.

Actually, if the Higgs field didn’t exist, neither of these particles would have any mass at all!

Now, in the press you don’t hear about the Higgs field but rather the Higgs boson. How are these two things related? The Higgs boson is the smallest bit of the Higgs field.

To understand how that works we should again return to water. Everyone knows what water is. If you’re immersed in it you know that water is everywhere. It’s a continuous medium and there are no holes in it. We also know that water is made of molecules – specifically H20. If you hold these two ideas in your head with the realization that water consists of countless individual molecules you can now begin to appreciate the Higgs boson. The Higgs field that gives subatomic particles their mass is made of countless individual Higgs bosons, just like water is made of individual molecules.

(Explanation #2 transcript quote) Without a doubt, the most exciting scientific observation of 2012 was the discovery of a new particle at the CERN laboratory that could be the Higgs boson, a particle named after physicist Peter Higgs. The Higgs Field is thought to give mass to fundamental, subatomic particles like the quarks and leptons that make up ordinary matter.

The Higgs bosons are wiggles in the field, like the bump you see when you twitch a rope. But how does this field give mass to particles? If this sounds confusing to you, you’re not alone.

In 1993, the British Science Minister challenged physicists to invent a simple way to understand all this Higgs stuff. The prize was a bottle of quality champagne.

The winning explanation [analogy] went something like this: Suppose there’s a large cocktail party at the CERN laboratory filled with particle physics researchers. This crowd of physicists represents the Higgs field. If a tax collector entered the party, nobody would want to talk to them, and they could very easily cross the room to get to the bar. The tax collector wouldn’t interact with the crowd in much the same way that some particles don’t interact with the Higgs field. The particles that don’t interact, like photons for example, are called massless.

Now, suppose that Peter Higgs [a celebrity] entered the same room, perhaps in search of a pint. In this case, the physicists will immediately crowd around Higgs to discuss with him their efforts to measure the properties of his namesake boson. Because he interacts strongly with the crowd, Higgs will move slowly across the room. Continuing our analogy, Higgs has become a massive particle through his interactions with the field.

So, if that’s the Higgs field, how does the Higgs boson fit into all of this? Let’s pretend our crowd of party goers is uniformly spread across the room. Now suppose someone pops their head in the door to report a rumor of a discovery at some distant, rival laboratory. People near the door will hear the rumor, but people far away won’t, so they’ll move closer to the door to ask. This will create a clump in the crowd. As people have heard the rumor, they will return to their original positions to discuss its implications, but people further away will then ask what’s going on.

The result will be a clump in the crowd that moves across the room. This clump is analogous to the Higgs boson.

In our analogy of the party, all particles are equal until they enter the room. Both Peter Higgs and the tax collector have zero mass. It is the interaction with the crowd that causes them to gain mass.

So, let’s recap. A particle gets more or less mass depending on how it interacts with a field, just like different people will move through the crowd at different speeds depending on their popularity. And the Higgs boson is just a clump in the field, like a rumor crossing the room.

Of course, this analogy is just that — an analogy, but it’s the best analogy anyone has come up with so far.

So, that’s it. That’s what the Higgs Field and the Higgs boson is all about.

See also: YouTube > Fermilab > “Higgs Boson 2016” – Don Lincoln (Nov 16, 2016) for a follow-up.

The Higgs boson burst into the public arena on July 4, 2012, when scientists working at the CERN laboratory announced the particle’s discovery. However the initial discovery was a bit tentative, with the need to verify that the discovered particle was, indeed, the Higgs boson. In this video, Fermilab’s Dr. Don Lincoln looks at the data from the perspective of 2016 and shows that more recent analyses further supports the idea that the Higgs boson is what was discovered.

(transcript quote) Was it the Higgs boson predicted by Higgs and Englert back in the 1960s? Or was it one of many? Those are very important questions. But one of those questions was particularly important question and needed to be answered. [Namely, whether the Higgs field gave masses to bosons AND fermions.]

The Higgs field is kind of like a bandaid theory that was added on. It gave mass to the particles that transmit the weak force and didn’t give mass to the particle that transmits electromagnetism. The name of the weak force particles are the W and Z bosons, while the name of the particle that causes electromagnetism is the photon.

… the original Higgs theory only gave masses to bosons. But it would sure be economical if the Higgs field would also give mass to the fermions. It doesn’t have to be that way- the massive fermions and heavy bosons could have gotten their mass from different sources. So a very important test was to see if the fermions also got their mass from the Higgs field.

Notes

[1] Paul Sutter is an astrophysicist at The Ohio State University and the chief scientist at COSI science center. Sutter is also host of Ask a Spaceman, RealSpace and COSI Science Now. He contributed this article to Space.com’s Expert Voices: Op-Ed & Insights.

[2] Published on Mar 23, 2017 – Can we stop with “The God Particle”? – Part One! What does the Higgs Boson mean? What role does it play in the forces of nature? What makes it so special? … these questions and more in today’s Ask a Spaceman!

One thought on “Not so deific particle – Higgs boson

  1. Contrary to the identical properties (like mass) of every electron, the mass of some “particles” is uncertain, has a range of energies.

    This article talks about commutative and non-commutative properties, contrasting the classical and quantum worlds.

    Forbes > “This Is Why Two Higgs Bosons Don’t Have The Same Mass As One Another” by Ethan Siegel, Senior Contributor (Aug 7, 2019).

    When we talk about a real particle that exists, you don’t have to worry about this type of energy uncertainty if the particle is stable. The reason is simple: stability means its lifetime is infinite. … But if your particle is unstable, meaning that its lifetime itself is uncertain (there’s a real Δt), then its energy (ΔE) must be uncertain, too.

    The Higgs boson only lives for around 10^-23 seconds, and has a substantial ΔE as a result: its mass is uncertain by a few MeV in energy over the median value. … Other short-lived, very massive particles, like the W or Z boson, have similar intrinsic properties and even larger widths (or ΔE): their masses are uncertain by ~2-3% as well.

    But the worst offender of all is the top quark. The top quark is the shortest-lived particle in the entire Standard Model, living for just 0.5 yoctoseconds on average, or 5 × 10^-25 s. When you create a top quark, it might live for half or a quarter of that average time, or for twice or thrice that time, or anywhere in between. There will similarly be an average mass to the top quark, but each value will follow a bell-curve-shaped distribution.

    This is not some artifact of how we measure it or a limitation of our detectors; these variations in the top quark’s mass actually change from particle to particle. In other words, each individual top quark doesn’t necessarily have the same mass as the top quark next to it!

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