Antiparticle

The Fundamental Building Blocks of Matter

The multitudinous different materials we come across in our day-to-day life are all essentially made up of the very same building blocks. There was, of course, a time when no one could even have imagined antimatter-existing out of elements that are the very opposite of those that combine to constitute these ordinary substances.

But then, one might wonder, can’t something exist simply because it is beyond our imaginative and conceptual powers?

The Power of Imagination and Scientific Breakthroughs

For instance, did anybody imagine in the old days that hundreds of tons of heavy vehicles one day would fly through the sky with a speed of thousands of kilometers per hour?

But today, such heavy vehicles are flying across the skies, breaking all the chains that those limited imaginations had made. Another example is that, in 1928, physicist Paul Dirac published an equation involving electrons. This equation presented a challenging mathematical problem which needed some deliberation and analysis.

Paul Dirac’s Radical Hypothesis: Antimatter

This paradox, therefore, suggests that there can be two varieties of electrons: one may have a negative charge, while the other may have a positive charge.

While a negatively charged electron is a fundamental particle, as they combine together with the nucleus to form atoms, which are the essential building blocks of visible matter; the positively charged anti-electron, or positron, combines with an anti-nucleus to form antimatter.

Paul Dirac advanced the radical hypothesis that, associated with each fundamental particle existing in the universe, there must be an oppositely charged counterpart-a whole new chapter in particle physics.

In fact, as a direct consequence of this sensational proposal, the scientific community began its extensive and determined quest to discover these elusive antiparticles.

The Search for Antiparticles

In today’s discussion, we are going to talk about what antimatter is, the differences between normal matter and antimatter, what baryogenesis is, how antimatter is artificially created and preserved, and what could be the potential future applications of antimatter.

Visible Matter and Atoms

Everything that is visible around us, including everything like soil, stones, plants, metals, non-metals, inanimate objects, living beings, liquids, and gases, is actually made up of very small tiny particles called atoms.

These are considered to be the fundamental building blocks, and when a number of these atoms join together, they form molecules. Molecules unite with each other and collectively form what we call matter.

In essence, it is crucial to know that at the center of every atom lies its central portion, which is called the nucleus, and it consists of two types of particles: protons (p+) and neutrons (n). At the same time, electrons (e–), tiny negatively charged particles of matter, travel in orbits around the nucleus.

Every atom has a proton in its nucleus with a positive electric charge. To complement this, accompanying the proton is a neutron that is neutrally charged, meaning it has no electric charge at all. Electrons circle this atomic nucleus and are classified as fundamental particles since they have negative electric charge.

The Properties of Fundamental Particles

Electron (e–): The electron is a fundamental particle and an essential member of the lepton family, which is a category of subatomic particles. The mass of an electron is roughly 9.109×10^–31 kg, a value so minuscule it is often practically regarded as being zero for most calculations and considerations.

Besides its small mass, the electron carries a spin of 1/2, showing its intrinsic angular momentum, and it has a charge of –1e, equal to 1.602×10^–19 coulombs, which defines its electrical properties and interactions with other charged particles.

Proton (p+): A proton is made of quarks (up and down quarks) and has a mass of about 1.67×10^–27 kg. It also has a spin of 1/2. Its charge is +1e or 1.602×10^–19 coulombs, the opposite of an electron.

-Neutron (n): Like protons, neutrons are also made of quarks (up and down quarks) and have a mass of about 1.675×10^–24 kg, with a spin of 1/2. Neutrons are electrically neutral.

Atomic Stability

The basic principle in an atom is that the total number of protons found in the nucleus is equal to the total number of electrons orbiting around the nucleus in defined energy levels.

However, it is important to note that a nucleus cannot be composed solely of protons because these positive particles would act against one another by repulsive forces, hence causing an instability within the nucleus.

To provide and maintain stability within the nucleus, neutral particles called neutrons are also involved along with the protons.

Protons and neutrons are bound together by a strong interaction that is known as the strong nuclear force and is essential to provide overall stability to the nucleus against the intrinsic repulsive forces between the protons.

The only well-known exception to the preceding rule is hydrogen, which happens to have no neutrons whatsoever. Hydrogen contains just one proton.

In passing, it’s of course worth noting that hydrogen does have radioactive isotopes. Examples are tritium and deuterium. These isotopes do contain different numbers of neutrons in the atom.

Antimatter: A New Kind of Matter

In antimatter, the fundamental building block known as the nucleus is composed of antiprotons, which possess a negative electric charge, and antineutrons, which carry no electric charge and are neutral, much like their regular neutron counterparts found in ordinary matter;

however, they differ in that antineutrons have an opposite baryon number.

Additionally, the electron, a well-known particle in conventional matter, has a corresponding counterpart in the realm of antimatter called the positron, which is distinguished by its positive electric charge.

Antimatter particles are characterized by their negative baryon or lepton numbers, while matter particles have positive values.

Properties of Antimatter Particles

Positron (Anti-Electron): The positron is the counterpart of the electron. It belongs to the lepton family, has the same mass as the electron (9.109×10^–31 kg), and a spin of 1/2. However, its charge is the opposite of the electron, +1e or 1.602×10^–19 coulombs.

Antiproton: As would be expected, the antiproton is the antiparticle of the proton. Like the proton, it is composed of quarks (in this case anti-quarks) and has a mass of 1.67×10^–27 kg. It has a spin of 1/2, but its charge is –1e or 1.602×10^–19 coulombs.

Antineutron: Antineutron is the direct antiparticle to neutron with exactly the same mass of 1.675×10^–24 kilograms. It also has a spin of 1/2, typical for such particles. Like a neutron, antineutron is electrically neutral, containing no net electric charge. Its baryon number, however, is negative, which makes it different from its neutron counterpart.

What is Baryogenesis?

About 10^–43 seconds after the monumental event that was the creation of the universe, in which everything got rolling, the laws of physics actually started to apply and become effective. This very short timescale is, in fact, known as the Planck Time.

After the epoch that defined the Planck Time, there had occurred-in about 10^-35 seconds-a critical phase transition. Thereby, this had constituted the incredible beginning of cosmic inflation; an era when the universe expanded exponentially, the evolution which remade the early structure and dynamics of the universe completely.

Creating and Preserving Antimatter

We know that everything comes from energy, and out of this energy, electron-positron pairs were created. In turn, they could annihilate each other, with the destruction of both particles and energy release.

What distinguishes particles from their antiparticles is electric charge. The electron and positron have the same mass and spin; however, they have opposite electric charges. When both meet, they annihilate each other and create a huge amount of energy.

This process continued in the early universe, where particles and antiparticles were created and annihilated symmetrically. However, an asymmetry occurred, which left behind some particles.

This slight imbalance between the number of quarks and anti-quarks led to the survival of normal matter, forming stars, planets, and all visible structures in the universe. This process is known as baryogenesis, the imbalance between matter and antimatter.

The Process of Creating and Storing Antimatter

The process of making artificial antimatter and how it is preserved: The artificial production and storage of antimatter is an acknowledged very complicated and challenging process.

However, it is still possible to produce single antiparticles, a task that can be achieved in controlled environments like particle accelerators and also naturally through radioactive decay.

Recently, a major breakthrough has been achieved by scientists successfully producing an anti-helium nucleus, an important milestone for antimatter research.

Challenges of Storing Antimatter

Creation is much easier than storing antimatter, as the creation process involves much fewer problems compared to maintaining the created antimatter.

For scientists to study antimatter successfully, it needs to be preserved in a stable state. The stability of matter is essential since it annuls almost instantly upon contact with regular matter, with the sudden release of energy.

Protecting Antimatter from Annihilation

To prevent this instantaneous annihilation scientists using electromagnetic fields. Imagine a vacuum tube in which there is a specific design to create antimatter. If the walls of that tube were made up of regular matter, then because of that fact, the antimatter would annihilate upon contact with those walls.

There is, however, a respite: if someone were able to create a special magnetic field embracing the tube, then the antimatter can be kept from touching the walls of the tube directly. This marvelous device that does such a thing is called a Penning Trap.

Complementary Techniques for Trapping Antimatter

It is important note that not all types of antiparticles can be trapped with just this technique. Hence, other methods, too, such as the use of ion traps, are used to complement the weaknesses of the Penning Trap and to further better the trapping of antimatter.

The Annihilation Process

When matter and antimatter annihilate each other upon contact and release high-energy photons, such as gamma rays. This is where the huge amount of energy release in annihilation takes place.

If matter and antimatter were brought together, a massive explosion would take place, destroying both and releasing a tremendous amount of energy.

In principle, quantum mechanics dictates that particle-antiparticle pairs are constantly created and then annihilated within an empty vacuum. In simpler terms, these are known as quantum fluctuations: even space, apparently a vacuum, is never quite empty of activity or existence.

Applications and potential uses of Antimatter:

Modern science is now examining a plethora of new plans and possibilities concerning this mind-boggling proposition known as antimatter.

If we can learn to produce and store large amounts of antimatter, there is a huge potential for using it in the production of spacecraft that could possibly travel far faster than the speed currently possible.

Surprisingly enough, a small amount of antimatter has the potential, when combined with regular matter, of unleashing a huge amount of energy, enough in fact, to destroy an entire small city.

This tremendous release of energy could change space travel forever and can also be used as a positive source of energy in the future.