5. Radius of the Proton (Hydrogen Nucleus)
For further development, it is necessary to find the proton’s radius. According to the Physicist Arthur Beiser on the nucleus motion in his book ‘Concepts of Modern Physics’ [
3], the nucleus of a hydrogen atom (proton) revolves around the center of mass shared with the electron. The rotation of both the electron and nucleus arises from considerations of momentum conservation in an isolated system and is taken into account by a computational correction called the reduced mass of the electron. The notion of reduced mass played an important part in the discovery of the deuterium and also corrects a small but definite discrepancy between the predicted wavelengths of the spectral lines of hydrogen and the measured ones. The center of mass is very close to the axis of the nucleus because of its larger mass; thus, we can assume that the trajectory depicted by the nucleus while revolving around the center of mass lies at a distance almost equivalent to the nucleus radius. We will denote this radius as the proton radius, validated in the final result. As a side note, this radius is not equivalent to the proton’s charge radius; however, there is a connection between these two parameters, which will be clarified in
Section 5b. To find the proton’s radius, we will use known formulas generated for the Natural units of the Stoney [
4] and Planck [
5] scales
. We will start with the Stoney scale, from which we will move to the Planck scale.
The Stoney length
in natural units is
The Stoney mass
from the natural units is
where
is the gravitational constant. Rewrite Eq. (22) for the gravitational constant
:
By substituting the relation
introduced by the physicist Arnold Sommerfeld
[
6], in Eq. (23), we obtain
The orbital angular momentum of the proton at the trajectory around the center of mass should be expressed by the reduced Planck constant. The proton’s velocity at this trajectory is denoted here as
. An initial estimation of this velocity yield approximately one fifth of the speed of light in vacuum. Hence, it is necessary to add a relativistic element
with
:
where
is the proton mass,
is the ratio of
to
, and
is the proton radius. By substituting the expression of
from Eq. (25) in Eq. (24) and reducing the expression, we obtain
The is similar to the fine structure constant , also known as the electromagnetic coupling constant, and it appears in the electron’s velocity expression at the Bohr radius as .
We can divide Eq. (21) by Eq. (22) (
is reduced, and the elementary charge
is partially reduced):
Then rearrange Eq. (27) to obtain an expression for
:
By setting the expressions in Eq. (28) and Eq. (26) equal to each other, we have
We then divide both sides of Eq. (29) by
, multiply both sides by
, reduce, and rearrange:
Eq. (30) presents a similarity between the right and left flanks (mass component and length component). The expression is split into two parts on the right-hand side of the equation because it contains the solutions corresponding to actual experimental results in the final analysis. The following new expressions are proposed solutions for the Stoney units.
New expression of Stoney mass
:
New expression of Stoney length
:
Note that the
expression in Eq. (30) represents a dimensionless number, for instance, the number of charged particles in one Coulomb
unit.
This number, as a multiplier, creates a quantity of charged particles (in our case, the number of protons contained within the Stoney mass, which corresponds to a quintillion protons) or, as a divisor, creates the smallest length (in our case, a contracted radius of the proton within the Stoney mass under internal attraction forces, which corresponds to a quintillionth of the proton radius that represents the Stoney length). It is displayed in the following equations as in Eq. (31), indicating that the value is dimensionless.
The gravitational constant
in Stoney units from Eq. (28) with the proposed new expressions is:
We can then set Eq. (23) and Eq. (32) equal to each other and substitute the square of the Stoney mass term
in the denominator of Eq. (23) as:
* See also section #9 further on for the new expressions proposed for the Stoney mass and length, developed from a different aspect!.
Multiplying both sides of Eq. (33) by
, reducing, and rearranging yields
The expression of Eq. (34) shows the equivalence of
, where the right-hand side (in brackets) contains the expression of the Planck constant
with the proton parameters introduced in Eq. (25). This result confirms the choice of the proposed solutions for the Stoney units of mass and length from Eq. (30). Although this option was based on a logical consideration, there are additional combinations that could be chosen that yield incorrect results. We multiply the numerator and denominator of Eq. (32) by
to obtain the gravitational constant
at the Planck scale
Note: The difference between the Stoney and Planck units arises from the need to multiply Planck units by the square root of the fine structure constant . We obtain the following expressions.
New expression of Planck mass
:
New expression of Planck length
:
By using the Planck mass in natural units and the new expression of Planck mass, we can derive the expression and value of
. The Planck mass defined by natural units is
Setting Eq. (36) and Eq. (37) as equal:
Then rearrange Eq. (38) to obtain an expression for
:
In Eq. (39), we substitute the values of and the following values from NIST CODATA 2018:
and
We obtain
The relationship of
to the nuclear research is through the strong coupling constant in QCD as follow
This value compares well with the value obtained experimentally [
7,
8],
.
Using the Planck length from natural units and the new expression for the Planck length, we can derive the expression and value of the proton radius
.
The new expression for the Planck length from Eq. (35) is
By setting the expressions in Eq. (40) and Eq. (41) as equal, we obtain
We then rearrange Eq. (42) for the proton radius
:
Substitutingin Eq. (43) and the values and from NIST CODATA, yields
This value compares well with the value obtained experimentally [
9], explained below
:
The proton radius obtained in Eq. (43) complies with the experimental formulation that assumes a spherical nucleus.The Fermi equation for the nuclear radius : , Whereis the atomic number and is from experimental results:. For the Hydrogen, and .
The proton charge radius
represents the maximum distance from the proton axis that the electron or the muon reaches in their penetration to the proton. This radius is:
Substituting the following in the expression for
;
and
, we obtain
. This value is similar to the NIST value of
.The proton’s Compton wavelength from Eq. (25) is
Substituting the values of
and
in Eq. (44) yields
This value compares well with the NIST CODATA value of
The last result shows that combined with the proton radius obtained from Eq. (43) and used in Eq. (44) is entirely consistent with the value of the proton’s Compton wavelength from NIST CODATA 2018, confirming the validity of our approach.
To obtain the gravitational constant
, we utilize Eq. (32) and substitute the
from NIST CODATA 2018 and also
,
and
:
It yields
Which compares well with the NIST CODATA value
7. Additional Expressions for the Proton and Neutron Masses and Radii
We divide Eq. (3) (with
by Eq. (25) as follows:
By rearranging Eq. (48) and solving for the proton mass, we obtain
Substituting
from Eq. (12) in Eq. (49) yields the following expression for the proton
Substituting
and
in Eq. (48) yields
We substitute
and
from Eq. (12) in Eq. (51) to obtain another expression for
:
Substituting the values of from NIST CODATA 2018 in Eq. (52), it gives the proton mass
(53)
This value matches well with the NIST CODATA value of .
We can rearrange Eq. (47) to obtain the orbital angular momentum of the neutron:
We then divide Eq. (3) by Eq
. (54), as follows:
Rearranging Eq. (55) for the neutron mass, gives
Substituting
from Eq. (12) in Eq. (56) yields an expression for the neutron mass
:
Substituting
from Eq. (13) and
from Eq. (47) in Eq. (55) yields
Substituting the values of
from NIST CODATA 2018 in Eq. (59) for the neutron mass
:
This value compares well with the NIST CODATA 2018 value of .
The ratio of proton mass to electron mass is obtained from Eq. (49). After rearranging and substituting the NIST CODATA 2018 values for
,
and
and
, it gives
This ratio can also be obtained from Eq. (51). This value matches well with the NIST CODATA ratio of
The ratio of neutron mass to electron mass is obtained from Eq. (56). After rearranging and substituting NIST CODATA 2018 values for
,
and
and
, it gives
This ratio can also be obtained from Eq. (58). This value matches well with the NIST CODATA ratio of
8. The meaning of the Permittivity of Vacuum Constant from a Different Aspect
The electron in the Hydrogen atom revolves around the center of mass shared with the proton as was described in section #5. Let’s assume now that the virtual photons, responsible for the force acting between them, collide with the virtual shell that represents the supposed locations of the electron at the Bohr level (The absorption and emission process). What if it is possible to describe the virtual photons’ rapid motion within the shell space in terms of molecules in an ideal gas?
The centripetal force
that holds the electron at Bohr radius
level
[10], is
And the electric force
that holds the electron at Bohr radius
level, is
The condition for a dynamically stable at Bohr radius
level, is
Multiplying both sides of Eq. (65) by
, it gives
We obtain at the left side of Eq. (66) the kinetic energy
of the electron at
level, as follows
where
is the electron mass, and
is the electron velocity at
level.
where
is the elementary charge of the electron, and
is the vcuum permittivity constant.
The average kinetic energy
of the virtual photons exchanged between the electron and the proton that support the movement of the electron in its trajectory at the Bohr level (as an approximation of
molecules in motion in Ideal gas from the mechanical point of view
), is
where
is the volume contained within the spherical shell, and
is the pressure that the virtual photons impose on the spherical shell. Substituting
from Eq. 67 in Eq. 69, as flollows
The pressure
is defined as the force acting on a given surface. If the spherical shell surface is
, and
is the Bohr radius, then the pressure, is
where
is the total force imposed by the virtual photons on the inner surface of the spherical shell. Substituting Eq. (71) into Eq. (70) and rearrange, it gives
The same mathematical development can be applied for the potential energy defined as
Substituting Eq. (68) (from
at Eq. (66)) and Eq. (71) in Eq. (73) and rearrange, it gives
Setting Eq. (74) as equal to Eq. (72) with reducing the integer 2 from both sides
Now setting the value of the expression in parentheses at the left side of Eq. (75) as equal to unity, here
And then substituting the last expression obtained in Eq. (76) for
in the right side of Eq. (75), we obtain the electrostatic force acting on the electron at the Bohr level from Eq. (2) at section #1, as
Note, that Eq. (76) shows the relation between the Bohr radius and the vcuum permittivity constant that corresponds with the conclussion from the analysis of Equation #8 at section #2.
For comparison to Eq. (76), let’s set Eq. (15), as follows
The expression in the parentheses equals to the following
It Shows that
This leaves the square of the magnetic flux quantum , as appropriate description of the mass!