General Astronomy/Higgs Boson

A simulated collision data that creates a Higgs Boson.

The Higgs Boson theoretical particle is a focus of keen interest for high-energy particle physicists. However, the Higgs Boson is also forging a strong bond with cosmologists that is likely to grow as the study of modern physics unfolds. Particle physicists regularly create exotic particles that have not existed abundantly and naturally since the earliest moments of the universe, which has been an important step in drawing the disciplines together. The discovery of the Higgs Boson could benefit cosmology by resolving some unanswered questions in the current theory. The mutually beneficial nature of this relationship becomes more apparent as the costs rise to perform high energy particle collision experiments. The next generation of particle experiments may rely on high-energy particles from space to attain higher power collisions for a lower price. This beneficial merging of fields is being called Astroparticle Physics (or Particle Astrophysics). This chapter will focus on how the Higgs Boson is essential to both parties' theories and how they are collectively seeking to discover the elusive Higgs particle.

What is the Higgs Boson?

2010 Sakurai Prize Winners - Kibble, Guralnik, Hagen, Englert, and Brout, the members of the other groups that published alongside Higgs. Higgs also was part winner, but was not pictured.

The Higgs component of the particle name bears no physical significance. It is named after Peter Higgs who independently published results around the same time as two groups released similar and related material. In 2010, all six contributors to the Higgs theory received the J. J. Sakurai Prize for Theoretical Particle Physics.

The Boson component does bear physical significance. Bosons are a class of particles that are governed by Bose-Einstein statistical theory and have the ability to occupy the same quantum state. This behavior is disallowed by most more commonly known particles (Protons, Neutrons, Electrons, which are Fermions) by the Pauli Exclusion Principle. It is a mark of importance as the mediating forces are considered Bosons. This includes: Photons, Gluons, the W and Z, the Higgs, and the Graviton (like the Higgs, currently just theoretically proposed to exist). Bosons have integer spin: the first four above have spin one, the Higgs theoretically has 0 spin, and the Graviton theoretically has spin 2.

The Periodic Table of Elementary Particles.

And what does it do?

Theoretically the Higgs Boson is the particle form of the mediating Higgs Mechanism, also known as the Higgs Field. The Higgs Field is supposedly responsible for the mass of all particles, and so the substance to all things in the universe. It is also a possible answer to the asymmetry between matter and anti-matter that makes our reality possible (if equal the universe would be filled only by energy). It is the only undiscovered particle of the Standard Model of Elementary Particle Physics. The Higgs Mechanism is the supposed field that endows all the components of nature with mass. Thus, if the Higgs Boson is discovered it will confirm the existence of the Higgs Mechanism which shows that the entire universe is permeated by the field and without it no object would have mass.

A simple example with familiar terms for how it operates is a party. If someone of low social worth to those present walks in they will be largely ignored as they make their way around. This matches a particle of little mass passing through the universe quite freely because it has less interaction with the Higgs Field. However, if someone who is idolized by the members of the party enters, people will quickly gather around them and make it quite difficult for free motion. This is the equivalent of massive particles that are greatly bogged down by the Higgs Field. The only neglected component in this example is massless particles. One could introduce them as follows: enter a small child that has utterly overdone a reasonably alloted quantity of sugar. The participants generally ignore the child as it runs around the room easily squeezing through gaps in people barring some mishaps where the child hits a person.

Connection of the Higgs Boson to Cosmology

The timeline of the universe in a visual form including the period of inflation

The Higgs Boson theoretically has an obvious link in the sense that there's a lot of massive objects in the universe from basic masses like the quarks that comprise hadrons to our Earth, Sun, and the Milky Way's super-massive black hole. However, the connection has a deeper core than that.

When the Universe was Less Massive than You

The title is not a lacking-class, physics-based fat joke: there's some merit to it. It is actually believed in Cosmology that there was a period early in the universe where not even Photons manifested themselves because the temperature was so great. That is, there was no light at all in the very early universe. This principle is believed to extend to the Higgs Boson and Mechanism as well. This has a greatly profound implication: immediately following the Big Bang the universe had zero mass because there was nothing there to endow anything present with mass. This was very brief (on the order of tiny fractions of a second), but a vital consideration to make for Cosmology.

This could be one potential explanation for the phenomenon of inflation where the universe was able to expand extremely rapidly early in the universe to explain why the universe currently appears to be flat or very nearly flat despite this contradicting expectations based on models of the universe.

What's the Antimatter?

The content of the universe relative to age.

Another problem with the Benchmark Model of the universe is that it lacks a clear explanation of why the Big Bang produced more matter than antimatter (hence the absolute lack of abundant, naturally occurring antimatter). If it was consistent with other Laws of Physics, there would have been an absolute match in quantities that resulted in the entire matter content of the universe having annihilated with the entire antimatter content of the universe leaving essentially no matter behind.

This problem, properly titled: the asymmetry of the universe, has been delegated to be potentially caused by the Higgs Mechanism causing a minor asymmetry in the early universe that ultimately caused the matter-prevalent universe that surrounds us. The Benchmark Model indicates the asymmetry as unimaginably small to most of us: that is, once upon a time there was 1,000,000,000 quarks, but only 999,999,997 antiquarks. Those three bachelor quarks, when propagated over the massive quantity of material involved in the Big Bang, became all the baryonic matter we see today while the rest annihilated with their significant antiquark other.

This rouses another curiosity of Dark Matter, much of which is believed to be non-baryonic (essentially: isn't made of Protons and Neutrons that comprise the elements of the Periodic Table which, in turn, comprise all the molecules that represent everything someone not delving deeply into Physics needs to know about). A pressing question for the near-future of Cosmology: what exactly is this large quantity of matter not comprised of the remains of asymmetry that appears to be present (by observations) in a quantity five times larger than the baryonic matter that comprises everything we know? But that's a digression from this chapter and fairly unfamiliar ground to even the boundaries of Physics at this point.

Where in the World is the Higgs Boson?

A map of the LHC particle accelerators with experiments labelled.

So, this particle seems pretty important towards the greater fate of the universe, how are this Physicists coming together to find it? This is where the chapter probably gets more familiar as the Large Hadron Collider (LHC) has been greatly popularized in recent years as the "Big Bang Machine." It's not the first, but it's the shiny new, fast, and powerful accelerator on the block that will, if it exists, be able to provide the energies necessary to create it for sure whereas its predecessors wouldn't if it's heavier than expected. But first, lets explain how the search works before detailing the handful of experiments that are working, perhaps competing is a better term, to be the first to find it.

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To be added later.