1. Introduction
At the fundamental level of matter, particles are
described by wave-particle duality, charges and their spin property. These
properties are revealed from light interactions and are pursued by the
application of relativistic quantum field theory (QFT) [
1,
2]. The theory of special relativity defines
lightspeed,
c to be constant in a vacuum and the rest mass of particles
to be,
with
E as energy. The particle-like
property of light waves consists of massless photons possessing spin 1 of
neutral charge. Any differences to its spin, charge and mass-energy equivalence
provide the inherent properties of particles for the matter at the fundamental
level and this is termed causality [
3,
4].
Based on QFT, particles appear as excitation of fields permeating space at less
than lightspeed. There is a level of indetermination towards unveiling of the
charge and spin property, whereas the wave-particle duality is depended on the
instrumental set-up [
5,
6]. The probability of
locating the electron within the atom is defined by non-relativistic
Schrödinger’s electron field,
, and it is not compatible to the excitation of the
electromagnetic field for particle manifestation [
7].
In other words, it is difficult to imagine wavy form of particles freely
permeating space without interactions and this somehow collapses to a point at
observation [
8].
At the atomic state, the energy is radiated in
discrete energy forms in infinitesimal steps of Planck radiation,
±h.
The interpretation is consistent with observations except for the resistive
nature of proton decay [
9]. The preferred
quest for particle observation at the atomic level is to make non-relativistic
equations become relativistic due to the shared properties of both matter and
light at the fundamental level as mentioned above.
Beginning with Klein-Gordon equation [
10], the energy and momentum operators of Schrödinger
equation,
are adapted in the expression,
Equation 2 incorporates special relativity,
for mass-energy equivalence,
is the del operator in 3D space, ℏ is reduced Planck constant
and
is an imaginary number,
. Only one component is considered in Equation 2
and it does not take into account the negative energy contribution from
antimatter. In contrast, the Hamiltonian operator,
of Dirac equation [
11]
for a free particle is,
The
has four-components of fields,
with vectors of momentum,
and gamma matrices,
α,
β
represent Pauli matrices and unitarity. The concept is akin to, e
+ e
–
⟶ 2 𝛾, where the electron
annihilates with its antimatter to produce two gamma rays. Antimatter existence
is observed in Stern-Gerlach experiment and positron from cosmic rays. While
the relativistic rest mass is easy to grasp, how fermions acquire mass other
than Higgs field remains yet to be solved at a satisfactory level [
12]. But perhaps, the most intriguing dilemma is
offered by the magnetic spin ±1/2 of the electron and how this translates to a
Dirac fermion of four-component spinor field. Such a case remains a very
complex topic, whose intuitiveness in terms of a proper physical entity remains
lacking and it is often described either by Dirac belt trick [
13] or Balinese cup trick [
14]. Others relatable descriptions include Klein
bottle [
15] and Dirac scissors problem [
16]. Suppose the atom is conserved, how the
electron is physically transformed into Dirac fermion is examined within a
proposed a monopole pair (MP) model. Such a process is compatible with Dirac
belt trick, its field theory and other associated features like space-time
dynamics, non-relativistic wave function and Feynman diagram with charge
conjugation, parity and time reversal (CPT) symmetry breaking. The model though
speculative, it could become important towards defining the fundamental state
of matter and its QFT.
2. Limitations of quantum field theory
In relativistic QFT, the atom is expected to be
eventually reduced to fundamental particles like fermions and bosons based on
the 2
nd law of thermodynamics. These would permeate space and any
excitations from light interactions should permit their observations. Such a
notion is adapted into Yukawa’s relativistic range of interaction,
R = ℏ/
mc with the
incorporation of the uncertainty principle [
17]
and this forms the underlying non-abelian Yang-Mills theory of the Standard
Model (SM). The relativistic mass,
m = 0 sustains unitarity and gauge
invariance [
18]. The SM accounts quite well for
the propagation of electromagnetic field in space, quark confinement and the
property of asymptotic freedom and the observable particles but at the expense
of infinite,
R [
19]. Similarly,
m
≠ 0 draws divergent terms to the Fourier Transform integral,
with
k equal to 4
th dimensional
variable [
20]. Renormalization of particle
self-interaction by Feynman diagrams to account for any exponential increase
with exchanges of virtual photons adapts Dirac fermion of four-component spinor
as its base [
1,
2]. The corrective measures are
employed by the SM lagrangian for infinite high-order terms for energy
conservation, while the transition from
m = 0 to
m > 0 is
attributed to dynamic chiral symmetry breaking like the Higgs mechanism to
confer a particle’s mass. The theory has seen tremendous success, whereby it
ably accounts quite well for all observations made so far into the electroweak
force interactions. However, for strong nuclear interactions of proton-proton
collisions, the absence of supersymmetric partners offers an enigma [
21,
22] to the actual nature of the atom. In this
study, how Dirac fermion of a hydrogen atom could be interpreted within the
geometry of a MP model is examined with its implications to the application of
QFT.
4. Dirac field theory and its associated features
The descriptions of Dirac fermion based on the MP
model can further the Dirac field theory. In this section certain components of
the field theory and its related features [
1,
2,
10,
11] are explored in bullet points for their relevance to this undertaking.
- ⇒
Discrete symmetries. The
electron of a body spinning about an axis (isospin) offers chiral symmetry to
the model. Its transformation to
Dirac fermion field,
and
its
vector
gauge invariance exhibit chiral symmetry by the relationships,
or
The exponential factor,
iθ provides the
position,
i of a complex number and the associated angular momenta,
θ.
The unitary rotations of right-handedness (
R) or positive helicity and
left-handedness (
L) or negative helicity are applicable to the electron
transformation to Dirac fermion (
Figure 2a).
The process is confined to a hemisphere and this equates to spin 1/2 property
of a complex spinor (
Figure 2b). Two
successive rotations of the electron in orbit at more than clockwise precession
of the MP field is identified by
. The chirality or vector axial current at the
point-boundary is assigned to polarization, ±1 of the model. The helical
symmetry from projections operators (isospin) acting on the spinors based on
Figure 2b is,
and
Dirac matrices of eigenstates,
for the spinor field is assumed at fixed momentum
at an energy level. The usual properties of projection operators are:
L
+
R = 1;
RL =
LR = 0;
L2 =
L and
R2
=
R. The boundary conditions are provided in Equation (4).
- ⇒
Space-time
dynamics.
Dirac fermion or spinor is denoted
ψ(
x) in 3D Euclidean space and
it is superimposed onto the MP model of Minkowski space-time,
ψ(
x,t)
by clockwise precession of the MP field (
Figure 3a).
Space itself is devoid of any reference points and thus, the Dirac
four-component spinor,
is
attributed to a 3D object (electron) in orbit,
and
it sustains
the
arrow of time as the principle axis of the MP field in asymmetry,
at
the point-boundary. Positions 0 to 3 are hermitian conjugates of positions 4 to
7 and the electron is restored at position 8. Their translation to linear time
of Fourier transform is offered in
Figure 3b.
The area defined by Dirac spinor when superimposed
on the surface of Poincaré sphere can relate to both positive and negative
curvatures of non-Euclidean space (
Figure 3a).
The latter is attributed to the electron orbit of time reversal and this is
normalized by the former of geodesic motion from spherical rotation.
Convergence of positions 1 and 3 at either position 0 or 2 is consistent with
Equation (4) and is relevant to the equivalence principle of general
relativity. The straight paths of the Dirac spinor define Euclidean space (
Figure 2a). Any light paths tangential to the
point-boundary is expected to transform Dirac spinor into linear time
comparable to Fourier transform and thus, induce wave function collapse (
Figure 3b). The probabilistic outcome of the
spin is given by Born’s rule,
, with only one outcome permitted. The past or
future events of the electron path from positions 0 to 8 are not accounted for
in the observation of particle property. The shift in positions is Hermitian,
P(0→8)
=
in Hamiltonian space with
equal to clockwise precession. Continuity of the electron orbit against precession reflects Euler’s formula,
+ 1 = 0.
- ⇒
Non-relativistic wave function. The point-boundary at singularity identifies with Planck length. Observation by light-matter interaction allows for the emergence of the model from the point-boundary and this generates complex fermions, ±1/2, ±3/2, ±5/2 and so forth at the energy shells of BOs (
Figure 4a). Their orbitals of 3D are defined by total angular momentum,
and this incorporates both orbital angular momentum,
l and spin,
s. From a hemisphere, the model is transformed to a classical oscillator. By clockwise precession, a holographic oscillator from the other hemisphere of the MP field remains hidden. One oscillator levitates about the other (
Figure 4b) and both are not simultaneously accessible to observation due to constraints placed by the electron as a physical entity and the influence of its orbit from clockwise precession. The
n-levels or shells for the fermions can be pursued for Fermi-Dirac statistics with the point-boundary assigned to zero-point energy (ZPE). Likewise,
splitting (
Figure 4a) can apply to Landé interval rule due to the electron isospin and this can accommodate lamb shift and thus, hyperfine structure constant. Such scenario is comparable to how vibrational spectra of a harmonic oscillator for diatoms like hydrogen molecule incorporates rotational energy levels. The quantum nature of the classical oscillator is also relevant to the spherical coordinates for the interpretation of Schrödinger wave equation (
Figure 4a).
- ⇒
Feynman diagram and CPT symmetry breaking. Feynman diagrams of path integrals incorporate both matter and antimatter coupling and annihilation processes. These can demonstrate the paths of
m = 0 at unitarity to
m > 0 for symmetry breaking. When two electrons from a pair of MP models (ionized hydrogen molecules or atoms) approach each other, both attraction and repulsion can occur due to electron-positron transition at the point-boundary. Secondary photons mimicking the electron-positron pair can acquire mass with unitarity sustained (
Figure 5a). Ejection of an electron (or positron) by beta decay,
would insinuate particle-hole of isospin mimicking up and down quarks (
Figure 5b). These interpretations are consistent with the transformation of the electron of isospin to Dirac fermion (
Figure 2a). Particle-hole coupling can lead to
W± bosons and neutrinos and antineutrinos of helical property mimicking the electron-positron pair without requiring change of color charges by exchange of gluons from up and down quarks. In this case, the vertices of the MP models assume center of mass and ejection of the electron/positron may constitute violation of charge conjugation, parity and time reversal symmetry. The suggestion is also made for the bosons of neutral charge and whole integer spin would amass at ZPE of the point-boundary of a classical oscillator (
Figure 4a). The difference in mass of the bosons by mass-energy equivalence such as for
W± can be attributed to constriction and relaxation of the model into
n-dimensions or energy shells. Any scatterings at the
n-dimensions (
Figure 4a) can accommodate the fine-structure constant,
and it is applicable to high energy at
.
- ⇒
-
Dirac field. The fermion field is defined by the famous Dirac equation of the generic form,
where
are the gamma matrices related to the shifts in the electron’s position by clockwise precession acting on its orbit. The exponentials of the matrices,
are assumed by the electron of 3D object.
is assigned to the vertex of the MP field due to radiation from the electron-positron transition at position 0 and somewhat sustains arrow of time in asymmetry. The
variables are of Dirac matrices and these are applicable to the electron of 3D object and shift in its position. The orthogonal projections of the space-time variables,
within a hemisphere are assigned to a light cone (
Figure 4a). These are all incorporated into the famous Dirac equation,
where
c acts on the coefficients A, B and C and transforms them to
and
. Alternatively, the exponentials of
are denoted
i, where
is off-diagonal Pauli matrices assigned to a pair of light cones in Minkowski space-time (
Figure 1b and
Figure 4b). It is defined by,
and zero exponential,
as,
is relevant to oscillations assumed at the BOs at the intersections of the light cones (
Figure 4a) and incorporate anticommutation relationship,
(
Figure 4b). The matrices, 0 and 1 are applicable to polarization of the model towards the point-boundary at position 0 (
Figure 3a).
- ⇒
Weyl spinor. The light cone from the point-boundary within a hemisphere accommodates both matter and antimatter by parity transformation to generate Dirac spinor (
Figure 4b). It is described in the form,
and it correspond to spin up fermion, a spin down fermion, a spin up antifermion and aspin down antifermion. The electron’s shift in positions from 0 to 3 and 4 to 7 are conjugates before its restoration at the point-boundary as the base of Hilbert space for the MP field. By assuming its own antimatter within a light cone of a hemisphere, the Dirac fermion somewhat resembles Majorana fermions. It is difficult to observe them due to shift in the electron position by clockwise precession. Non-relativistic Weyl spinor of a pair of light cones relevant to Schrödinger wave equation are of holographic type (
Figure 4a,b). These are defined by the reduction of Equation (10) to bispinor of the type,
where
are Weyl spinors of chiral form attributed to the electron of a physical entity. Hence, its parity operation
x →
x’ = (
t, ‒
x) generates qubit 1 and −1 at the vertices of the MP field (
Figure 1a and
Figure 3a). Depending on the reference point-boundary, the exchanges of left- and right-handed Weyl spinor are of the process,
Conversion of Weyl spinors to Dirac bispinor,
are assumed diagonally at positions 1 and 3 (
Figure 4a). Comparably, the two-component spinor,
= 1 are normalized at the point-boundaries of the MP model and ensues the orthogonal relationship,
and
.
- ⇒
Lorentz transformation. The Hermitian pair,
of Dirac fermion transiting at positions, 0, 1, 2 and 3 of BOs is not Lorentz invariant in 1D space (e.g.,
Figure 2b) due to radiation from electron-positron transition at the point-boundary. The same applies to Weyl spinor at spherical lightspeed due to the existence of the electron of chirality (
Figure 4a). Thus, Lorentz transformation of Weyl spinor depicts the relationship,
Equation 13 relates to Minkowski space-time by clockwise precession of the model (
Figure 1b). The corresponding Lorentz scalar applicable to scattering at the BOs (
Figure 4a,b) is,
and is referenced to time axis of the MP field of a dipole moment in asymmetry (
Figure 2a). By identical calculation to Equation (13), the Weyl spinor becomes,
for the complete classical rotation of the model. Though observations may not distinguish Weyl spinor and Majorana fermion from Dirac spinor, the explanations offered in this section for the MP model provide some intuitive forms to their possible existence.
Quantized Hamiltonian. Clockwise precession of the MP field is quantized at the point-boundary for the emergence of Dirac spinor and this preserves unitarity (
Figure 2a). Two ansatzes adapted from Equation (7) are given as follows,
These are hermitian plane wave solutions and they form the basis for Fourier components in 3D space (e.g.,
Figure 3b). By decomposition, quantized Hamiltonian assumes the relationships,
The coefficients
and
are ladder operators for
u-type spinor and
and
for
v-type spinor. These are applicable to Dirac spinors of two spin states, ±1/2 and
and
are the antiparticles. The operators can somehow relate BOs into
n-dimensions for the production of complex fermions, ±1/2, ±3/2, ±5/2 and so forth for the observable oscillator (
Figure 4a). By parity transformation, the observable and holographic oscillators are canonically conjugates (
Figure 4b) and its momentum is given by,
In 3D space, the generated oscillations of lagrangian mechanics and its Hamiltonian becomes,
The quantity in the bracket is the Dirac Hamiltonian of one-particle quantum mechanics relevant to the MP model for hydrogen atom type (see also Equation (3)). With
z-axis of MP field assigned to time axis in asymmetry of (
Figure 3a), the V-A currents from the vertices are projected in either
x or
y directions in 3D space by the relationships,
where
α and
β denote the spinor components of the
. Equations (20a) refers to the unitarity of the model and Equation (20b) is assumed by the electron-positron transition that temporarily insinuate radiation (
Figure 2b). The
independent of time in 3D space obeys the uncertainty principle with respect to the electron’s position,
p and momentum,
q, as conjugate operators. These are described by the polar coordinates, (
r, θ, Φ) with respect to the electron position (
Figure 3a). The commutation relationship of
p and
q obeys the relationship,
Equation (21) incorporates both matter and antimatter and their translation to linear time (
Figure 3b). The electron as a physical entity and its transition into space allows for a positive-frequency such as,
Equation (22) may explain the dominance of matter (electron) over antimatter if the latter is accorded to the conceptualization process of Dirac fermion (
Figure 2a,b).
- ⇒
Further undertakings. The themes provided above with respect to Dirac field theory and its related features can be further pursued into depth with the model serving as an approximate intuitive guide. The list could extend to include others such as energy-momentum tensor of Dirac field, Fermi-Dirac statistics, Bose-Einstein statistics, causality, Feynman propagator, charge conjugate-parity-time symmetry and so forth.