THE PROTON: ITS UNTOLD STORY

We have all heard of the proton. It is one of the standard atomic particles. The proton and the neutron make up the nucleus of the atom. This means that it is one of the basic building blocks of everything we know in the universe, everything! This makes the proton pretty important in our universe. Just some quick fact/information about the proton;

Ernest Rutherford is credited with discovering the proton in 1911.

In the Standard Model (particles) it is a Baryon and comes under the category of Fermions.

I put this info about the proton being a Baryon in the category of Fermions for two reasons; to introduce the “Standard Model” because we will be talking about that a lot, and to show how complicated things can get.

Here is where it gets good, how many protons are there?

The standard answer that we have all been taught for years is one, there is only one proton. This is not exactly true. There are at least three different protons and I would argue that there are four.   

The current information associated with the standard model is that the proton is made up of three first generation quarks. The first generation quarks are the “up” quark and the “down” quark. The ‘up’ and ‘down’ quarks are all that we need to be concerned with for this piece.

As I just stated there are three quarks in the proton. But since there are only two quarks that are being used one of them must be doubled, it is the ‘up’ quark. So, the proton is made of two ‘up’ quarks and one ‘down’ quark. It turns out that there are a whole bunch of rules that need to be followed for combining quarks into particles, thank you quantum physics. One of the rules is commonly referred to the exclusionary principle and it basically says that I cannot have two of the same quarks combined in a particle. But, the proton has two ‘up’ quarks so how is this combination allowed in the proton…. Well the current theory is that all quarks come in three colors; red, blue and green. These are not “real” colors, rather they are assigned identifiers. And, since there are three colors of quarks in order to avoid exclusionary conflicts any particle made of three quarks must be color neutral. In the case of the proton we will say that color neutrality is obtained by having one quark of each color.

So, when we use the rules with what we have we come up with the following protons…. (Note that “protons” is plural, and for individual identity purposes each proton has been named by the color of the ‘down’ quark.)

Blue Proton => DOWN blue, UP red, UP green

Red Proton => DOWN red, UP green, UP blue

Green Proton => DOWN green, UP blue, UP red

Each of these three protons are color neutral and they do not have the same ‘up’ quark, they comply with the rules.

In looking at our universe and making things work, the simple statement would be that all three of these protons behave exactly the same. So, how do we know this? We do not. A red rose is not a yellow rose and not all roses are the same as there is the rose bush, the climbing rose and many other kinds of rose plants. I also believe that a logic argument could be made that since there is a required color neutrality and exclusionary principle they cannot be the same.

Let’s convolute this even more. In the standard model there is a whole class of particles called “Baryons.” All Baryons are made up of three quarks. We already have three varieties of the proton so this should be the close of the matter. Not so fast. There is also the “Delta+” Baryon made up of two ‘up’ quarks and one ‘down’ quark just like our proton. The difference is that the Delta+ Baryon has about a 30% greater rest mass than the proton. In other words, the Delta+ Baryon is the same as the Proton, just more rest mass. (This relates to a really great question, how does a standard proton obtain a 30% greater rest mass?)

Let’s toss one more little interesting piece of information into this mess; a free Proton has an estimated half-life of about 10³² years, which is a one followed by 33 zeros. For perspective the universe is about 13.8 billion years old, for comparison 13.8 X 10⁹ years old. The Delta+ Baryon, the proton that isn’t a proton, it has a lifetime (not a half-life) of 0.6 X 10^-23 seconds. This is 23 zeros between the ‘6’ and the ‘.’.      

Let me list the above times for a better visual comparison:

The free Proton has a half-life of 10³² years,

And the Delta+ has a lifetime of 10^-23 seconds.

This existence difference due only to a 30% energy difference does not make any sense, it is just illogical.

One more piece of information, the neutron which is the partner of the proton in the nucleus of all atoms that make up everything in the known universe is also made up of three quarks, two ‘down’ and one ‘up’ (flip one of ‘up’ quarks in a proton to a ‘down’ quark and you have a neutron. There is a 0.1% energy difference between a neutron and a proton. Guess what, a free neutron has a half-life of about 12 minutes. This too is a long, long way from the proton’s half-life. And guess what happens when a neutron decays, it becomes a proton and a few other things.

Let’s put all of this together. You have a free neutron; free in this case means it is out there all by itself and is not part of the nucleus of any atom. In about 12 minutes this neutron is going to become a proton, and a few other things, and doing this it is now going to basically live forever. Unless, something happens to it and it picks up about 30% more rest mass and becomes a Delta+ baryon (proton), then it is going to die in a blink of an eye and become a regular proton again, which it what it was before it changed and died. Why would nature do this, what purpose does all of this serve?

I just read a passage where a physicist said that he likes consistency in numbers, and that there was an additional “beauty” when numbers align. With respect to the standard model of particles as I recall he was talking about how the number three was consistent in so many things associated with this model. Well, here are a couple of more threes. I just showed that there were three varieties of protons as well as three states for the proton. Let’s randomly put the varieties of protons identified above with a state;

Blue Proton => DOWN blue, UP red, UP green: assigned to the bound state in an atom.

Red Proton => DOWN red, UP green, UP blue: assigned to the free, unbound state.

Green Proton => DOWN green, UP blue, UP red: assigned to the Delta+ state.

Why did I do this, because it is impossible to say that this cannot occur. There are three distinct varieties of protons as shown above. There are also three specific states that the proton can be in. So tell me why there cannot be some kind of matchup between proton variety and states. And, this is just two more incidents of the number three, which according to some should be a beautiful consistency.

Something to think about, and a few things that should be readily explainable.