Explaining the proton mass and radius

Our alternative realist interpretation of quantum physics is pretty complete but one thing that has been puzzling us is the mass density of a proton: why is it so massive as compared to an electron? We simplified things by adding a factor in the Planck-Einstein relation. To be precise, we wrote it as E = 4·h·f. This allowed us to derive the proton radius from the ring current model:

proton radius

This felt a bit artificial. Writing the Planck-Einstein relation using an integer multiple of h or ħ (E = n·h·f = n·ħ·ω) is not uncommon. You should have encountered this relation when studying the black-body problem, for example, and it is also commonly used in the context of Bohr orbitals of electrons. But why is n equal to 4 here? Why not 2, or 3, or 5 or some other integer? We do not know: all we know is that the proton is very different. A proton is, effectively, not the antimatter counterpart of an electron—a positron. While the proton is much smaller – 459 times smaller, to be precise – its mass is 1,836 times that of the electron. Note that we have the same 1/4 factor here because the mass and Compton radius are inversely proportional:

ratii

This doesn’t look all that bad but it feels artificial. In addition, our reasoning involved a unexplained difference – a mysterious but exact SQRT(2) factor, to be precise – between the theoretical and experimentally measured magnetic moment of a proton. In short, we assumed some form factor must explain both the extraordinary mass density as well as this SQRT(2) factor but we were not quite able to pin it down, exactly. A remark on a video on our YouTube channel inspired us to think some more – thank you for that, Andy! – and we think we may have the answer now.

We now think the mass – or energy – of a proton combines two oscillations: one is the Zitterbewegung oscillation of the pointlike charge (which is a circular oscillation in a plane) while the other is the oscillation of the plane itself. The illustration below is a bit horrendous (I am not so good at drawings) but might help you to get the point. The plane of the Zitterbewegung (the plane of the proton ring current, in other words) may oscillate itself between +90 and −90 degrees. If so, the effective magnetic moment will differ from the theoretical magnetic moment we calculated, and it will differ by that SQRT(2) factor.

Proton oscillation

Hence, we should rewrite our paper, but the logic remains the same: we just have a much better explanation now of why we should apply the energy equipartition theorem.

Mystery solved! 🙂

Post scriptum (9 August 2020): The solution is not as simple as you may imagine. When combining the idea of some other motion to the ring current, we must remember that the speed of light –  the presumed tangential speed of our pointlike charge – cannot change. Hence, the radius must become smaller. We also need to think about distinguishing two different frequencies, and things quickly become quite complicated.

The Mystery Wallahs

I’ve been working across Asia – mainly South Asia – for over 25 years now. You will google the exact meaning but my definition of a wallah is a someone who deals in something: it may be a street vendor, or a handyman, or anyone who brings something new. I remember I was one of the first to bring modern mountain bikes to India, and they called me a gear wallah—because they were absolute fascinated with the number of gears I had. [Mountain bikes are now back to a 2 by 10 or even a 1 by 11 set-up, but I still like those three plateaux in front on my older bikes—and, yes, my collection is becoming way too large but I just can’t do away with it.]

Any case, let me explain the title of this post. I stumbled on the work of the research group around Herman Batelaan in Nebraska. Absolutely fascinating ! Not only did they actually do the electron double-slit experiment, but their ideas on an actual Stern-Gerlach experiment with electrons are quite interesting: https://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1031&context=physicsgay

I also want to look at their calculations on momentum exchange between electrons in a beam: https://iopscience.iop.org/article/10.1088/1742-6596/701/1/012007.

Outright fascinating. Brilliant ! […]

It just makes me wonder: why is the outcome of this 100-year old battle between mainstream hocus-pocus and real physics so undecided?

I’ve come to think of mainstream physicists as peddlers in mysteries—whence the title of my post. It’s a tough conclusion. Physics is supposed to be the King of Science, right? Hence, we shouldn’t doubt it. At the same time, it is kinda comforting to know the battle between truth and lies rages everywhere—including inside of the King of Science.

JL

The proton radius puzzle solved

I thought I’d stop blogging, but I can’t help it: I think you’d find this topic interesting – and my comments are actually too short for a paper or article, so I thought it would be good to throw it out here.

If you follow the weird world of quantum mechanics with some interest, you will have heard the latest news: the ‘puzzle’ of the charge radius of the proton has been solved. To be precise, a more precise electron-proton scattering experiment by the PRad (proton radius) team using the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab has now measured the root mean square (rms) charge radius of the proton as[1]:

rp = 0.831 ± 0.007stat ± 0.012syst fm

If a proton would, somehow, have a pointlike elementary (electric) charge in it, and if it it is in some kind of circular motion (as we presume in Zitterbewegung models of elementary particles), then we can establish a simple relation between the magnetic moment (μ) and the radius (a) of the circular current.

Indeed, the magnetic moment is the current (I) times the surface area of the loop (πa2), and the current is just the product of the elementary charge (qe) and the frequency (f), which we can calculate as f = c/2πa, i.e. the velocity of the charge[2] divided by the circumference of the loop. We write:F1Using the Compton radius of an electron (ae = ħ/mec), this yields the correct magnetic moment for the electron[3]:F2What radius do we get when applying the a = μ/0.24…´10–10 relation to the (experimentally measured) magnetic moment of a proton? I invite the reader to verify the next calculation using CODATA values:F3When I first calculated this, I thought: that’s not good enough. I only have the order of magnitude right. However, when multiplying this with √2, we get a value which fits into the 0.831 ± 0.007 interval. To be precise, we get this:

Of course, you will wonder: how can we justify the √2 factor? I am not sure. It is a charge radius. Hence, the electrons will bounce off because of the electromagnetic fields. The magnetic field of the current ring will be some envelope to the current ring itself. We would, therefore, expect the measured charge radius to be larger than the radius of the current ring (a). There are also the intricacies related to the definition of a root mean square (rms) radius.

I feel this cannot be a coincidence: the difference between our ‘theoretical’ value (0.83065 fm) and the last precision measurement (0.831 fm) is only 0.00035 fm, which is only 5% of the statistical standard deviation (0.007 fm). Proton radius solved?

Maybe. Maybe not. The concluding comments of Physics Today were this: “The PRad radius result, about 0.83 fm, agrees with the smaller value from muonic and now electronic hydrogen spectroscopy measurements. With that, it seems the puzzle is resolved, and the discrepancy was likely due to measurement errors. Unfortunately, the conclusion requires no new physics.” (my italics)

I wonder what kind of new physics they are talking about.

Jean Louis Van Belle, 24 January 2020

PS: I did make a paper out of this (see my academia.edu or viXra.org publications), and I shared it with the PRad team at JLAB. Prof. Dr. Ashot Gasparian was kind enough to acknowledge my email and thought “the approach and numbers are interesting.” Let us see what comes out of it. I need to get back to my day job. 🙂

[1] See: https://www.nature.com/articles/s41586-019-1721-2. See also: https://www.jlab.org/prad/collaboration.html and https://www.jlab.org/experiment-research.

[2] Zitterbewegung models assume an electron consists of a pointlike charge whizzing around some center. The rest mass of the pointlike charge is zero, which is why its velocity is equal to the speed of light. However, because of its motion, it acquires an effective mass – pretty much like a photon, which has mass because of its motion. One can show the effective mass of the pointlike charge – which is a relativistic mass concept – is half the rest mass of the electron: mγ = me/2.

[3] The calculations do away with the niceties of the + or – sign conventions as they focus on the values only. We also invite the reader to add the SI units so as to make sure all equations are consistent from a dimensional point of view. For the values themselves, see the CODATA values on the NIST website (https://physics.nist.gov/cuu/Constants/index.html).