_{1}

One of the fundamental questions is that “what the matter is composed of?” In 1897, atoms are known as the basic building blocks of matter. In the year 1911, Ernest Rutherford demonstrated that when alpha particles are scattered on a thin gold foil that the atom is composed of mostly empty space with a dense core at its center which is called the nucleus. Thereafter, protons and neutrons were discovered. In 1956, McAllister and Hofstadter published experimental results of elastic scattering of the electrons from a hydrogen target which revealed that the proton has an internal structure. In 1964, Gell-Mann (and independently) Zweig proposed that nucleons are composed of point-like particles which are called quarks. These quarks are postulated to have spin-1/2, fractional electric charge. Combinations of different flavors of quarks yield protons and neutrons which belong to the type of particles called baryons (built up from three quarks) and mesons as (quark and an antiquark). These two groups of particles are categorized as hadrons. The quarks showed further decay properties which suggest ed that they have a substructure.

The fact that fundamental particles have quark substructures was introduced in 1964, following the success of the quark model and its decay modes. It was assumed that the quarks have substructures called the preons [

The work in Ref. [_{i} is given by

M i = δ + ∑ j = 1 3 m j i + ξ / 3 [ m 0 2 / ( m 1 i m 2 i ) σ 1 ⋅ σ 2 + m 0 2 / ( m 1 i m 3 i ) σ 1 ⋅ σ 3 + m 0 2 / ( m 2 i m 3 i ) σ 2 ⋅ σ 3 ] (1)

where δ and ξ are parameters to be determined, m^{i}_{j} labels the ith preon type (i.e., D, U, S, C, B, and T) for the three preons (j = 1, 2, and 3) that comprises the quark, m_{o} is the average mass of first generation preons (D and U), and σ_{k} (k = 1, 2, and 3) is the spin vectors for the preons incorporated into the quark. The last term in Equation (1) represents the spin-spin interaction of the preons and σ k ⋅ σ 1 has the values of −3/4 and +1/4 for singlet and triplet composite state, respectively. The last sentence which is wrong is repeated after Equation (1) by the same author in Ref. [

- The quarks are comprised of preons of the same type. For example, u quark is defined by 3 U preons and s quark is comprised of 3 S preons.

- There are 6 preons types: D, U, S, C, B, and T.

- The preons are in a relative S state in the mass formula of Equation (1). The mass (m) of the U preon is derived from the u → d + W + vertex, but the mass of the d quark is ignored in Equation (2):

m ( U ) = M ( W + ) / 3 (2)

Here again Equation (2) is wrong for two reasons:

Relativistic kinematics should be used i.e. for a decay of one particle M,

0 → 1 + 2

M 2 = − M 2 2 + 2 M E 2 + M 1 2

in the rest frame of particle 0.

Also, Equation (2) means that the three particles are not bound because of the division by 3.

- The mass of the D preon is related to the U preon and u and d quark masses as follows:

m ( D ) = ( M d / M u ) m (U)

- The δ and ξ parameters are determined from Equation (1) using the U and D preon masses.

- The quantity m_{0} is defined in a manner that is analogous to the first-order quark mass formula [

m 0 = ( m ( U ) + m ( D ) ) / 2

- The S, C, B, and T preon masses are determined from Equation (1), the U and D preon masses, the masses of s, c, b, and t quarks, and the δ and ξ parameters.

The fact that the quark quark forces differ from the preon forces as well as from the nuclear forces in their shapes and strengths suggests that one cannot import structure models from one system to another. Hence, one concludes that the model with the above previously reported mistakes is not valid and the tabulated data are undoubtedly erroneous and incomplete.

The authors declare no conflicts of interest regarding the publication of this paper.

Mansour, H. (2019) On the Preon Model. Open Journal of Microphysics, 9, 11-14. https://doi.org/10.4236/ojm.2019.92002