Dear Chian Fan

Upon your invitation, here are my comments with regard to the issue of "Are annihilation and pair production mutually inverse processes?"

First there is need to distinguish between theories and confirmed physical observations.

In theory, all charged particles are susceptible to convert back to free moving photon state. But in practice only one type of particle pairs is known be produced by free moving photon destabilization. They are a pair of electron and positron, first observed in bubble chambers in the early 1930's. It is unfortunate that almost no textbook actually mention these confirmed discoveries and instead systematically discuss this as if this still was only theoretical.

Blackett, P.M.S & Occhialini, G. (1933) Some photographs of the tracks of penetrating radiation,Proceedings of the Royal Society, 139, 699-724.

Anderson, C.D. (1933) Physical Review, 43, 491-194.

https://journals.aps.org/pr/pdf/10.1103/PhysRev.43.491

Also, it is experimentally proven that pairs of electron and positron that mutually capture in metastable positronium systems, quickly close in on each other to convert to 2 or more free moving electromagnetic photons, depending on whether they are in ortho- or in para-positronium spin state.

Direct collision between an electron and a positron is also on record at Fermilab to have converted to a single 1.022+ MeV photon at point A. The related image of experiment E632 is presented with explanation in this article:

Article The Mechanics of Neutron and Proton Creation in the 3- Spaces Model

in which the 1.022+ Mev photon is then on record to convert back into a new pair of electron and positron at point B.

Best Regards, André

This isn't a new subject, these are standard exercises in relativistic mechanics.

The interaction

γ + γ -> electrically charged particle + anti-particle

is possible iff the energy of the two photons is, at least, equal to 2mc2, where m is the rest mass of the electrically charged particle (which is equal to that of the antiparticle) that appears in the RHS.

Conversely

electrically charged particle + anti-particle->γ+γ

to the same polarization state and energy for the photons, if the energy (and momentum and angular momentum, etc) is the same as that of the first interaction also occurs.

It suffices to apply conservation of energy, momentum and angular momentum.

It would be a good idea to study relativistic mechanics...

Quote: "The interaction γ + γ -> electrically charged particle + anti-particle"

This is not what has been experimentally observed. What is on record is that a pair of electron and positron that collide head on converts to a "single" 1.022+ MeV electromagnetic photon, and that this "single" electromagnetic photon, that exceeds the 1.022 MeV threshold level, converts back into a pair of massive 0.511 MeV/c2 electron and positron.

Reference given above.

Once more: Conservation of energy and momentum matters. It is hard, in practice, to produce electromagnetic fields such that the energy in the initial state is greater than 2mc2, even for electrons; it is routinely done in accelerators, where the photons are ``off-shell''.

Which is what is meant by electron+positron->electron+positron; in the lowest order of perturbation theory the photon is NOT on-shell.

The decays of positronium have been observed. And electron + positron can't decay into a single photon, just from momentum conservation: In the center of mass frame the momentum of the electron+positron system vanishes, whereas the momentum of the photon can't... That's why the photons that are exchanged in the process electron+positron->electron+positron are not real photons-their energy-momentum relation isn't E2=p2c2.

Positronium can decay into two photons or into three photons.

A single photon can produce particle+antiparticle pairs in the presence of an external field...

Positronium decay is different from head-on collision. The conversion to a single photon of a pair on record is from a head-on collision, and reconversion of this single photon to a pair is also on record. Confirmed experimental records supersede theoretical assumptions.

Dear Chian Fan,

You can easily answer these questions yourself if you imagine that photons in the form of bosons are excited elements of one space, and fermions are elements of completely different one. That's why

1) the collision of photons with each other will never lead to the formation of elements of another (alien) space, for this the photon with sufficiently high energy must collide with the space that already contains and can generate elements similar to itself - fermions;

2) single photon colliding with such the space can only turn into a pair of particles, and these particles will necessarily be antiparticles with respect to each other so that the conservation laws known to us remain valid;

3) the reverse process of annihilation of two antiparticles requires the formation of already two photons, since in the surrounding space, generated by its own excited elements - photons, it cannot be otherwise;

4) in this case, the opposite charges of antiparticles, their masses, half spins disappear in the same way as two identical waves interfere with the phase shift necessary for this;

5) such "interference" takes place because the charge of the particle e is determined by the quantum of the magnetic flux μ through the quantum of action h: e = h/μ, here for different charges magnetic fluxes directed in opposite directions "interfere";

6) the opposite spins of antiparticles "interfere" in a similar way, and even their masses, since they are determined by the corresponding flows around them;

7) the energy of antiparticles does not go anywhere, since the process of annihilation or "interference" itself takes place in such a way that it excites the elements - photons in the surrounding space.

You can read a little about all this in one of two papers with my participation published here in ResearchGate.

Sincerely, Dulin Mikhail.

Dear André Michaud

Thank you very much for your comment. We have no objection to the idea that positive and negative electrons annihilate into photons p+p- → γ γ .

You have provided a valuable γ → p+p- theory, based on the 3-space hypothesis, which specifically describes how photons form positive and negative particles（I need to understand its meaning further）.

I think the relatively important aspect of the question is whether there is any experimental evidence to support the idea that positive and negative particles must occur in pairs when a "photon-photon" reaction (or a single photon acting on some "particle field") occurs. My reading of the experimental results is that the positive and negative particles may appear with equal probability. There is no strict evidence that they are concomitant.

Best Regareds， Chian Fan

Dear Mikhail N Dulin

You said, "Everything is space. Spaces are mass-less fields and massive particles." This is a novel and bold idea. Physics needs this kind of venture.

However, I am sorry that I am not yet able to accept the idea of discrete space and the concept of electromagnetic fields as space. Nor can I accept the theory that vacuum excitation produces bosons and fermions，Although it is a mainstream physics concept.

I hope I will have more discussions after I have fully understood your theory.

Best Regareds， Chian Fan

Dear Chian Fan,

I am glad for your kind response, it instills confidence in the possibility of further discussions and friendly relations. I agree with you that it is difficult to agree right away that everything is space. But over time, this can happen, because I see no other way for the development of physics.

Yours sincerely, Dulin Mikhail.

Dear Chian Fan

You wrote: "Thank you very much for your comment. We have no objection to the idea that positive and negative electrons annihilate into photons p+p- → γ γ"

From what I observe, they do not "annihilate". Their energy "converts" to electromagnetic photons state.

You wrote: " My reading of the experimental results is that the positive and negative particles may appear with equal probability. There is no strict evidence that they are concomitant."

It is of course your judgment call. But from my perspective, if a drop of water is split in 2, there is a hundred percent chance that the separation is concomitant. So if the energy "substance" of a photon separates in two parts that the bubble traces in the FERMILAB experiment E632 bubble chamber picture show that they move away from each other simultaneously, seems to me that they are concomitantly appearing and moving away from each other.

This photon structure is consistent with de Broglie's hypothesis about the double-particle photon that he conceived in the 1930's. Analyzed in this article:

Article De Broglie’s Double-Particle Photon (Expanded republication PI)

If interested, final analysis is carried out in Section 3 of this other article that was published only a few weeks ago:

Article Introduction to Synchronized Kinematic and Electromagnetic Mechanics

All original formal references are provided, with links to those that are directly available on the internet, for both articles.

Best Regards, André

“…This isn't a new subject, these are standard exercises in relativistic mechanics. The interaction γ + γ -> electrically charged particle + anti-particle is possible iff the energy of the two photons is, at least, equal to 2mc2, ….”

- that above in standard relativistic mechanics really looks as rather questionable claim. “γ + γ”, i.e. photons interactions, don’t exist, some claims that even at energies much-much more 2mc2 some “γ + γ” interactions were observed also look as rather questionable.

Though that

“…What is on record is that a pair of electron and positron that collide head on converts to a "single" 1.022+ MeV electromagnetic photon, and that this "single" electromagnetic photon, that exceeds the 1.022 MeV threshold level, converts back into a pair of massive 0.511 MeV/c2 electron and positron.…”

- is, of course, a too strange claim.

The really experimentally observed e± pair creation happens at interaction of a photon that has energy more 2mec2 with “Electric field” of some electric charge, mostly of large Z nuclei’ fields;

- and this effect is described in QED indeed as . “γ + γ” → e± pair ; but in the relation above one γ is real, while other γ is “virtual”, while at annihilation of a e±pair mostly two completely realphotons [at positronium decay 2x0.511 MeV] appear.

So when standard relativistic mechanics claims about some “annihilation and pair production mutually inverse processes” that really is some strange claim. Though that isn’t an unique strange thing in QED.

What really happens at creation of e± pair by some photon is really scientifically explained only in the Shevchenko-Tokarevsky’s 2007 initial model of [Gravity and] Electric Forces in

https://www.researchgate.net/publication/366536729_The_informational_model_-Gravity_and_Electric_Forces_Version_2

- when a photon impacts on the real – by no means “virtual” Electric Force mediator of, say, a nuclei charge, “circular photon” – which isn’t a particle, the impact transforms the “circular photon” into the e± pair.

More see the link, to read the Shevchenko-Tokarevsky’s 2023 initial model of Nuclear Force” in

https://www.researchgate.net/publication/369357747_The_informational_model_-Nuclear_Force it is useful as well; all these 3 Forces act by the same scheme, so real gravitons at impacting on Gravity Force mediators, and real π± and πo mesons, at impacting on Nuclear Force mediators, are created essentially [not completely, of course] by a same scheme as well.

Cheers

Dear André Michaud

Can you provide more original information about "the FERMILAB experiment E632 bubble chamber picture"? I have not found a more detailed paper or report (I have limited access to databases). The real "pair generation" looks better, but whether it is a real "pair generation" or a statistical "pair generation", the support of experimental data is necessary. It is clear to us that the distinction between the two is significant.

Best Regards, Chian Fan

Dear Chian Fan

Note that a bubble chamber photograph is not a "statistical graph" established from a set of data, but a "physical recording" of the actual trajectories traced by charged particles ionizing water molecules along their path that create small bubbles along the way, which is what allows photographing the actual trajectories followed by the charged particles.

In this photograph, can be seen the trajectory of a positron moving at a given velocity suddenly disappearing at point A, and on the prolongation of the same trajectory a little further on, two particles appear with opposite charges appearing at point B, that can be calculated from measurements on the picture as having the sum total of the energy that the single positron had at the moment of disappearing, moving in opposite directions in the ambient magnetic field.

This is the actual data of the experiment to be analyzed and interpreted. This data confirms to my satisfaction the behavior expected from the de Broglie conditions for localized photons to obey Maxwell's equations as listed and analyzed in this article:

Article De Broglie’s Double-Particle Photon (Expanded republication PI)

I found this article on the CERN site describing the 15 foot FERMILAB Bubble chamber used in experiment E632 and its operation:

http://cds.cern.ch/record/171757/files/CM-P00061167.pdf?version=1

It is no longer in service, from what I know. But no doubt you could contact some of the experimentalists at CERN that might still know about this case.

Note that I also have limited access to the databases.

Hope this helps.

Best Regards, André

Dear André Michaud

I understand what you are saying. It is to verify the simultaneity of the double trajectories of the bubble chamber that the original data needs to be analyzed. The bubble chamber trajectories, even if they appear to be simultaneous, cannot be considered as simultaneous because their "response times" are too large for us to distinguish if they are simultaneous or not, maybe they differ by 0.1us.

This is a very critical event, and I'm not sure if physicists think that "pair production" is inevitable and does not require a deep and careful analysis of the experimental phenomenon. All I see are statistical results, and various means are needed to distinguish them.

I hope someone can provide more valid evidence.

Best Regards， Chian

Dear Chian Fan

Wouldn't you expect the "response time" to be the same for both trajectories beginning at point B?

Sorry to say, but this all the data that I have for experiment E632.

This is not the first case I know about. In the 1930's French scientists also reported such a case, but I have no picture for the case that they refer to. I could look up to try and relocate my source if you wish. At the time, I thought that this was common knowledge in the community, so I never expected to have to refer to and to explain these experimental findings, and did not rigorously note this other source, thinking that E632 was sufficient as a more recent experimental reference.

In my case, seamless consistency with the electromagnetic decoupling mechanics emerging from the trispatial vector geometry for photons exceeding the 1.022 MeV threshold is what convinced me.

Best Regards, André

Dear André Michaud

I certainly hope the double tracks are simultaneous, because it looks so beautiful.

However, it is also necessary to do further verification as an adequate scientific study. I think this is your point as well. We look forward to more experimental analyses.

Best Regards, Chian Fan

Pair production is the creation of an elementary particle and its antiparticle, for example creating an electron and positron, a muon and antimuon, or a proton and antiproton. Pair production often refers specifically to a photon creating an electron-positron pair near a nucleus but can more generally refer to any neutral boson creating a particle-antiparticle pair. In order for pair production to occur, the incoming energy of the interaction must be above a threshold in order to create the pair, at least the total rest mass energy of the two particles and that the situation allows, both energy and momentum to be conserved. There exists an inverse process to pair production called pair annihilation, in which a particle and its antiparticle collide and annihilate each other, the total energy of the two particles appearing as electromagnetic radiation.

“…Pair production is the creation of an elementary particle and its antiparticle, for example creating an electron and positron, a muon and antimuon, or a proton and antiproton. Pair production often refers specifically to a photon creating an electron-positron pair near a nucleus but can more generally refer to any neutral boson creating a particle-antiparticle pair.….”, etc.

- what is pair production on an introductory/the quote above level one can read, say, in

https://en.wikipedia.org/wiki/Annihilation,

- however note, again, that the mainstream physics describes the of pair production fundamentally as the process, where some virtualparticles are involved, what is, again –see the SS posts in the thread – really is fundamentally wrong. Everything in Matter exists and happens only at interactions of real, i.e. by no means “virtual” , material structures.

Including, say, a e± pair is created not simply by an at least 1.022 MeV photon interaction “near a nucleus”, but when this photon specifically transforms a nucleus’s Electric field mediator “circular photon”, which isn’t a particle [more see SS post above and links in the posts 4 days ago now] into the pair.

At large energies, not only photons, but any other particles, create rather numerous particle-antiparticle pairs, but again – that happens at interactions of real corresponding fundamental Nature forces mediators and particles’ structures; in the Nuclear Force case at rather tolerant energies that transformations of this Force mediators “circular mesons” – particles π±mesons – more concretely real quark-antiquark pairs, etc., and so that

“…There exists an inverse process to pair production called pair annihilation,..”

- is, in certain sense, formally correct – the processes are formally “inverse”, however really they fundamentally aren’t physically mutually inverse; see again, the example in the SS post above: even in the simplest case of e± pair production/ annihilation at rather small energies: the production of e± pairs see above, while annihilation of the pair results again only in real particles “photons”. At other particles interactions the pairs production/annihilation the same happens – the pairs are created at interactions of particles and “not-particles”, i.e. Forces mediators, annihilations result in creation of real particles and not the mediators; at extreme energies the interactions, including the pairs production, are much more complicated, etc.

Cheers

For the "pair production" experiment, the 2021 STAR Collaboration collectively published a paper "Measurement of e+ e- momentum and angular distributions from linearly polarized photon collisions" [4].

"At RHIC, scientists accelerate gold ions to 99.995% of the speed of light in two accelerator rings. If the speed is high enough, the strength of the circular magnetic field can be equal to the strength of the perpendicular electric field," Xu said. perpendicular electric and magnetic fields of equal strength is exactly what a photon is-a quantized "particle "So, when the ions are moving close to the speed of light, there are a bunch of photons surrounding the gold nucleus. As the ions pass one another without colliding, two photons (γ) from the electromagnetic cloud surrounding the ions can interact with each other to create a matter-antimatter pair: an electron (e-) and positron (e+) [5]. [The headline of the media report is interesting [5][6][7]]

The history of the discovery of the physics of particle production and annihilation is presented in paper [1]; paper [3] is an analysis of the experimental phenomena by Anderson, the discoverer of positrons, in which four possibilities are proposed for each result, "pair production" being one of them. He finally determined that "pair production" was the real case. The results provided by André Michaud [9] should be similar [see his replies for details].

Comparing the STAR experiment 【Refer to the attached picture (right)】[5] and the E114 experimental method【Refer to the attached picture (left)】 [8], they produce photon "collisions" in a very different way. These two experiments are in turn different from experiments [2] and [3]. It is commonly believed that there are three possible interactions [4]: the collisions of two virtual photons (as calculated by Landau and Lifshitz, giving the total cross section for e+e- production predominantly at the pair threshold), of one virtual and one real photon (Bethe-Heitler process ), or of two real photons-the Breit-Wheeler process.

Question: Yang[1] and Andeson considered that Chao [2] and Anderson [3] are both electron pair generation processes, so is this a "photon-photon" collision "γγ → e+e- " process? If so, are the photons real or virtual, and what is the difference between them and the experiments [4][8]? If not, then there are no "photon-photon" collisions in the experiments of Chao [2] and Anderson [3], but only "photon-particle" collisions?

--------------------------------------------------------------------------------

Reference：

[1] Li, B. A. and C. N. Yang (1989). "CY Chao, Pair creation and Pair Annihilation." International Journal of Modern Physics A 4(17): 4325-4335.

[2] Chao, C.-Y. (1930). "The absorption coefficient of hard γ-rays." Proceedings of the National Academy of Sciences 16(6): 431-433.

[3] Anderson, C. D. (1932). "The apparent existence of easily deflectable positives." Science 76(1967): 238-239.

[4] Adam, J., L. Adamczyk and etl. (2021). "Measurement of e+ e− momentum and angular distributions from linearly polarized photon collisions." Physical Review Letters 127(5): 052302:

[5] "Collisions of Light Produce Matter/Antimatter from Pure Energy": https://www.bnl.gov/newsroom/news.php?a=119023

[6] "Colliding photons were spotted making matter. But are the photons 'real' ? ": https://www.sciencenews.org/article/colliding-photons-matter-particle-physics#:~:text=In%20a%20demonstration%20of%20Einstein%E2%80%99s%20E%3Dmc%202%2C%20collisions,colliding%20particles%20of%20light%20create%20matter%20and%20antimatter.

[7] "Scientists Generate Matter Directly From Light – Physics Phenomena Predicted More Than 80 Years Ago": https://scitechdaily.com/scientists-generate-matter-directly-from-light-physics-phenomena-predicted-more-than-80-years-ago/?expand_article=1

[8] SLAC. (1970). "SLAC Experiment E144 Home Page." from https://www.slac.stanford.edu/exp/e144/.

[9] the FERMILAB experiment E632 bubble chamber picture;

“…:For the "pair production" experiment, the 2021 STAR Collaboration collectively published a paper "Measurement of e+ e- momentum and angular distributions from linearly polarized photon collisions" [4].… [4] Adam, J., L. Adamczyk and etl. (2021). "Measurement of e+ e− momentum and angular distributions from linearly polarized photon collisions." Physical Review Letters 127(5): 052302:..”

- again, e±pair is created not simply by an at least 1.022 MeV photon interaction “near a nucleus”, but when real particle “photon” specifically transforms a nucleus’s Electric Force field real mediator “circular photon”, which isn’t a particle [more see SS post June 9 on page 2 and links in the posts] into the e± particles pair. As, say, real high energy particles “nucleons” specifically transform at interactions a nucleus’s Nuclear Force real filed mediators “circular mesons” into particles pairs π± and πo mesons.

While creations of e± pair fundamentally aren’t

- at some real γγ interactions, detection of a few such [extremely rare] events that were reported as be in [4] looks as haven’t sufficient confidence level,

- when “Collisions of Light Produce Matter/Antimatter from Pure Energy”; including the term “Pure Energy” physically looks as rather, if too, strange; in Matter fundamentally cannot be “pure” or “filthy” energies, though energy is “dumb” – and so universal – and so in every concrete cases concrete results of its acing are completely determined by what concrete material objects that interact at exchanging by energy;

- and at collisions of two virtual photons (as calculated by Landau and Lifshitz, giving the total cross section for e+e- production predominantly at the pair threshold), of one virtual and one real photon (Bethe-Heitler process ); since really some “virtual photons” exist only as some transcendent mathematical trick, so nothing real can be created at which.

More see the SS posts above and links in the posts.

Cheers