A particle that is formed entirely from ethereal, imaginary and neutral components can be difficult to characterize and distinguish from other phenomena. So if there are a lot of these elusive particles in a description then it may be more convenient to group them together and refer to them collectively as a field. Different sorts of fields are defined by different quark distributions.
The fields that we discuss most are electromagnetic fields. When considered as individual particles they are called photons. Photons are defined from quarks that are paired with their matching anti-quarks. Different types of photons are modeled by different combinations of these pairs. For example the gross spectrum of hydrogen is accurately described by rotating and electrochemical quark pairs. Other sorts of fields like gravity can also be modeled using these particles. Different combinations are associated with different forces. So we use them like building blocks and call them field quanta.
A simple field quantum is formed by a pair of quarks that are out of phase anti-particles to each other. By this definition, the net number of quarks is always zero. So these simple quanta have no mass, charge, baryon-number, lepton-number or strangeness. But they do have distinct temperatures and momenta that vary by quark-type. Here is a list of some simple field quanta.
We use the symbol to denote a simple field quantum. For any pair of quarks there are two possible arrangements that depend on their phases. That is, arrangements depend on the helicity of the reference frame as noted by or . For example consider the following pairs of negative quarks that have their phases illustrated by background shading.
Simple dynamic field quanta are little bits of momentum. They can be understood as parts or components of photons. Field quanta can move around between Newtonian particles by catching a ride on any passing photon. Momentum is conserved. So if a Newtonian particle interacts with a field quantum, then it experiences a force that is proportional to the momentum of . A field quantum and its anti-particle have their momenta pointed in opposite directions. So if one increases, then the other decreases the total momentum of any absorbing particle. Hence, the impressed force has two possibilities; like an attraction or a repulsion, or perhaps a push vs a pull. The direction depends on phase relationships.
In addition to the foregoing pairs, we also include and pairs as simple field quanta. This is because their internal energy is so small that distinctions between quarks and anti-quarks are negligible. Pauli’s exclusion principle is not violated because they are still distinguished by their phase. Thus there are four quanta composed from out of phase pairs of down-quarks. They all have the same temperature of -760 (K), which means that they are very stable. And they all have an internal energy that is very close to zero, about -54 micro electronvolts. This is utterly negligible in the realm of nuclear reactions where particle energies are typically trillions of times larger and measured in (MeV). It is also imperceptible in most atomic and chemical reactions where energies are about a million times larger. Indeed, almost the only experimental access we have to these elusive quanta comes from extremely precise observations of fine structure in atomic spectra. So by convention we almost always ignore them. These field components are known as dark quanta. They are illustrated in the following images which use background shading to indicate the phase.
These quanta are not energetically important as individuals. But since their internal energy is not perfectly zero, they may still be collectively relevant if there are enough of them. And enormous quantities are possible when considering astronomical distances. Then dark quanta may give rise to dark-energy, dark-currents and maybe even … dark forces?
Atomic and molecular interactions are mediated by fields and forces too. Long-distance forces may be carried by photons. But brief, short-range forces from collisions, explosions and chemical reactions can be accurately modeled using simple field quanta. For example see the following list of forces used to describe transitions between different excited states of hydrogen.
The combination of quarks noted as in the foregoing list is called the Lamb quantum. It is used a lot in spectroscopic models because interacting with changes the orbital angular momentum without altering the total angular momentum. For more about these quanta, please see the discussion of fine structure in the spectrum of hydrogen.
Simple field quanta are the building blocks of photons, but they may also be assembled into other force-carrying particles as well. For example, consider nuclear particles like the kaons. These strange particles have their rotating quarks arranged in unusual ways. So their interactions involve some different quanta too. The following strange quanta carry weak forces.
The relationship between field quanta and their forces can be developed in much more detail, but next we go back and focus on exactly what we mean by a photon.