Timeline for Experimental suggestions for size and shape of single optical photon (wavepacket)?
Current License: CC BY-SA 4.0
9 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Apr 30, 2021 at 8:05 | comment | added | Jarek Duda | But what is objectively? For such question there are preferred experimental arguments like discussed in the first article. I think there is no doubt that photon is EM field, which (nonperturbative) energy density is rho ~ |E|^2 + |B|^2, what can we we tell about shape of such density function? | |
| Apr 30, 2021 at 7:58 | comment | added | anna v | all this happening in probability values for finding a particle at (x,y,z,t). It does not mean that particular models for particular boundary conditions are wrong, if they are correct they should emerge from the basic QFT if one took the trouble to show. Also if people research outside main stream, it is absolutely legitimate, but their new theories should embed the old successful ones.For example string theory is popular with theorists because it embeds the standard model. | |
| Apr 30, 2021 at 7:55 | comment | added | anna v | The last is within quantum optics, as far as I gather and has not been peer reviewed yet. The photons of quantum optics can have a size, it is a different QFT. I am talking of the standard model QFTfrom which, mainstream physics posits that the elementary particles are point particles, that the photon wave function is from a quantized maxwell equation cds.cern.ch/record/944002?ln=en and the creation and annihilation operators on the photon field create point particles according to the theory. To describe a single particle, whether photon or electron or... one needs the wavepacket form | |
| Apr 30, 2021 at 6:38 | comment | added | Jarek Duda | Sure QFT, SM work to great precision, but referring to perfect point particles I understand you are referring to approximation as perturbative series in momentum space - asking for size, shouldn't you use nonperturbative in position space instead? I am not asking about density of particles, but about density of energy of EM field of single photon. During such observed 22as delay in photoemission, EM wave will travel ~6nm. Here is better link for this article with independent similar claim: arxiv.org/abs/1604.03869 | |
| Apr 30, 2021 at 6:30 | comment | added | anna v | your last link does not work. The delay should be within the width of the probability distributions for the interaction. All energy levels have a width after all | |
| Apr 30, 2021 at 6:22 | comment | added | anna v | Mainstream accepts that because the QFT of the SM works to great precision , the axiomatic acceptance of all point particles in the table is validated., In QM there is no density for the point particles , of anything, because it is all Quantum Mechanical Probabilities. When measuring a point particle there is a probability of being at a specific (x,y,z,t). There are no singularities in QM. . How classical fields emerge see here motls.blogspot.com/2011/11/… | |
| Apr 30, 2021 at 6:13 | history | edited | anna v | CC BY-SA 4.0 |
added link
|
| Apr 30, 2021 at 5:46 | comment | added | Jarek Duda | "The photon is point particle" would mean infinite energy density - so why it doesn't create a black hole? I think you are referring to Feynman diagrams - perturbative approximation, but the question is what is objectively: without approximation, accordingly to experiments like mentioned above. Real optical processes are not instant, but take e.g. attoseconds for photoemission ( science.sciencemag.org/content/328/5986/1658 ) - what happens during this time, how (nonperturbatively) EM field evolves? Similar photon sizes are here: arxiv.org/ftp/arxiv/papers/1604/1604.03869 | |
| Apr 30, 2021 at 5:18 | history | answered | anna v | CC BY-SA 4.0 |