Nuclear Particle Classification

Outline

Nuclear particle classification is scientifically expedient because experimental physicists have heroically observed hundreds of short-lived particles that are smaller than atoms, but bigger than quarks. These little quanta were discussed earlier because they are vital for developing a quantitative theory of mass. To summarize, so far we have defined the elementary particles of EthnoPhysics by objectifying some common sensations as seeds. Then we considered pairs of seeds and called them quarks. We talked about how quarks are counted and conserved. And we characterized them by their internal energy and temperature.

Over the next few pages EthnoPhysics uses collections of these quarks to make models of nuclear particles. As we consider larger bodies the number of quarks involved rises dramatically, especially for highly excited particles. And so to be useful, descriptions require some simplification. To manage this complexity we start by sorting quarks into two groups, field quarks and core quarks.

Field Quarks and Core Quarks

A few of the quarks in some particle P may be paired with their corresponding anti-quarks. These pairs are called field quanta. And the quarks in these $\mathsf{q \overline{q}}$ pairs are called field quarks. But field quanta do not have any mass of their own. So it is all the other quarks that determine P’s mass. These other quarks are supposedly located in the core of P, so they are called core quarks. The core may also include some rotating field quanta so that it can reify P’s angular momentum.

For both core and field, quark content is mathematically expressed using quark coefficients which are written as $n ,$ $\Delta n$ or $N.$ Various quantum numbers and the mass are defined from $\Delta n$ rather than $n$ because asymmetries are required for a particle to be distinct. But recall that ${\Delta}n^{\mathsf{Z}} = n^{\mathsf{\overline{z}}} - n^{\mathsf{z}} .$ So any interaction with a $\mathsf{q \overline{q}}$ pair will change $n ,$ but not $\Delta n .$ Variant particle models can always be obtained by adding more $\mathsf{q \overline{q}}$ pairs. Because of this possibility, the classification of nuclear particles depends on determining the minimum number of quarks required to represent each category or familial grouping. So field quarks are ignored, and the focus is on core quarks.

Particle Families

Hundreds of nuclear particles are sorted into just 25 families by omitting field quarks from further consideration. Emphasizing minima can also simplify classification in another way: Not all quark-types are relevant and some can just be completely neglected. For example leptonic quarks are not needed to outline the broad categories of nuclear phenomena. Also, since top-quarks are so highly correlated with bottom-quarks, we do not need to consider both quark-types when assessing the overall pattern of nuclear observations. One type is enough, and we use top quarks. Likewise for strange and charmed quarks. So the classification method presented below just relies on up, down, top and strange quarks. Other types are not required.

A third way of minimizing complexity is to ignore the distinction between particles and anti-particles. As for example, when both electrons and positrons are grouped together as leptons. Then we can more efficiently use seed coefficients to describe particles. These seed coefficients are written as $N^{\mathsf{Z}} = n^{\mathsf{\overline{z}}} + n^{\mathsf{z}}$ where $\mathsf{Z} \in \mathsf{ \left\{ U, D, T, S \right\} . }$

Superfluous $\mathsf{q \overline{q}}$ pairs are ignored by evaluating the minimum number of Z-type seeds in the core of a particle. These lower bounds are written as $N_{\mathsf{min}}^{\mathsf{Z}} .$ They are used to sort nuclear particles into 25 different categories or family groups, so they are called familial seeds. They are among the smallest aggregates that can distinguish particle families from each other. Iconic images of the familial-seeds for different particle-families are shown below.

Thus P is depicted with a kernel of familial seeds at its core, along with various other quarks which determine P’s individual character. Excited states are modeled by adding even more quarks. Click on any icon in the following list for more detail.

Classification by Down Quarks

The most important characteristic for nuclear particle classification is $N_{\mathsf{min}}^{\mathsf{D}}$ the minimum number of down quarks in a particle’s core. But this compound symbol is unwieldy, so we also use a simpler ‘hard-core’ glyph written as 🅓 $\equiv \! N_{\mathsf{min}}^{\mathsf{D}} .$ The list below shows 🅓 in descending order as particles become less baryonic and more leptonic, finally arriving at the Higgs boson. Click on any icon for a more detailed look at the quark models for each family.

🅓 = 16

🅓 = 12

🅓 = 10

🅓 = 8

🅓 = 6

🅓 = 4

🅓 = 2

🅓 = 0

Click on any icon in the foregoing list for a more detailed look at the quark models for each family. Calculated results are shown and compared with experimental observations. For EthnoPhysics, the most important reference for experimental data is provided by the Particle Data Group. This organization is an international collaboration of physicists that compile and reanalyze published results. The classification of nuclear particles shown above is just a rearrangement of this rich legacy.

Newtonian Particles

Newtonian particles are defined by their density and surrounding equilibrium. Conservation of their mechanical energy and momentum is evaluated.