Quantum Physics: the electroweak force (General)

by David Turell , Thursday, November 30, 2023, 17:17 (357 days ago) @ David Turell

Controls decay:

https://www.symmetrymagazine.org/article/what-is-the-electroweak-force

"The electromagnetic force and the weak force differ greatly in their functions, mechanisms, ranges and strength. But in the 1960s, scientists realized that both are expressions of a single, unified fundamental force: the electroweak force.

"When we look at how the electromagnetic and the weak nuclear forces function in our universe, it’s easy to see why physicists didn’t immediately catch on to their special relationship.

"Electromagnetism provides the electricity we use to access digital articles, like this one, and the visible light we need to see the words on our screens. It is responsible for the Earth’s magnetic field, which prevents us from being flash-fried by cosmic rays, and it even enables the chemical bonds required for biological life.

"The weak nuclear force, while also essential, is considerably less versatile. It is primarily responsible for radioactive beta decay, a subatomic process that causes unstable particles to transform into other, less massive particles. This decay is crucial for the nuclear reactions that power the sun and other stars.

"And electromagnetism and the weak nuclear force don’t differ just in their effects; the particles that make up each of these forces are just as distinct.

"One of the basic tenets of particle physics is that everything in our regular, everyday world is made of particles. These particles are really “local excitations,” essentially tiny wiggles, within quantum fields that pervade all of space. Each type of particle is described by a quantum field.

"A local excitation of the electromagnetic field is called a photon. All of the electromagnetic effects we observe are the result of the photon’s unique combination of qualities. It has no electric charge, and it has no mass. With nothing to slow it down, it zooms across the universe at lightspeed.

"The weak force is mediated by a different particle—three of them, in fact: the neutral Z boson and two W bosons, one bearing a positive and the other a negative electric charge. Relative to the fleet-footed photon, these three weak-force particles are heavy and comparatively slow. They’ll quickly disintegrate if they travel even the width of an atomic nucleus.

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"Physicists now understand that at some point in the fractions of seconds immediately following the Big Bang, there was one, combined electroweak force. Mere picoseconds later, this unified electroweak force split into the electromagnetic and weak forces we see today.

"For decades, scientists were unsure of how this transition happened, postulating that something must have broken this force apart. “When the universe cooled from a very high temperature down to lower temperatures, it underwent a phase transition at the energy scale at which the electroweak force breaks,” says Tevong You, an assistant professor in physics at King’s College London. “This is very similar to if you change the temperature of a pond, and you go from a liquid phase to ice” at 32 degrees Fahrenheit.

"Whatever broke apart the electroweak force during that phase transition had to result in the four original massless electroweak force particles transforming into three very massive weak-force particles and one massless electromagnetic particle, the photon.

"Based on this idea, scientists predicted the existence of a quantum field that could give mass to some (but not all) elementary particles: the Higgs field. In 2012, scientists at experiments at the Large Hadron Collider announced the discovery of the particle associated with that field, the Higgs boson."

Comment: Well, we learn how the Higgs boson was found. I've left out a complex discussion of gauge theory in which the constraints of a particle's activities are mathematically described. Remember all particles have fields of action.