A Universal picture of hadron interactions?

  • #1
40
1
As far as I know, the total cross-sections of the following hadron interactions are well described
by a single Reggeon trajectory and a single Pomeron (soft Pomeron) trajectory.
  1. ##K^-p: (11.93s^{0.0808}+25.33s^{-0.4525})mb##
  2. ##K^+p:(11.93s^{0.0808}+7.58s^{-0.4525})mb##
  3. ##\bar pn:(21.70s^{0.0808}+92.71s^{-0.4525})mb##
  4. ##pn:(21.70s^{0.0808}+92.71s^{-0.4525})mb##
  5. ##p\bar p:(21.70s^{0.0808}+98.39s^{-0.4524})mb##
  6. ##pp:(21.70s^{0.0808}+56.08.39s^{-0.4524})mb##
  7. ##\pi^-p:(11.63s^{0.0808}+36.02s^{-0.4525})mb##
  8. ##\pi^+p:(11.63s^{0.0808}+7.58s^{-0.4525})mb##
  9. ##\gamma p:(0.0677s^{0.0808}+0.129s^{-0.4525})mb##



The last expression is hard for me to understand: in the ##1## to ##20 GeV## range the photon and the proton seem to exchange a Reggeon trajectory and a Pomeron trajectory, although I would tend to think that it should be some kind of Compton scattering. I just don't get it, the only charge a photon sees is the EM charge!! Could anyone, please, offer a reasonable explanation?


Why are these results so unexpectedly accurate? This is a theory I do not particularly like but its results are very precise, specially if you add multiple Pomerons and the Odderon. No other phenomenological model is able to match its results.

These plots can be see in slides number 35 and 36 of the following presentation (from a physicist working at the "KEK Theory Center"):

https://indico2.riken.jp/event/2729/attachments/7480/8729/PomeronRIKEN.pdf
 

Answers and Replies

  • #2
1,206
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The last expression is hard for me to understand
Virtual quark loops in the photon propagator?
 
  • #3
40
1
Virtual quark loops in the photon propagator?
Do you mean that renormalization via virtual quark loops makes a real photon behave like a neutral meson? Could you, please, provide some references?
 
  • #4
Do you mean that renormalization via virtual quark loops makes a real photon behave like a neutral meson? Could you, please, provide some references?
1970s picture of photon-rho mixing, there is a review by Kurt Gottfried in an early 1970s QED conference hosted at Cornell. It's referenced in Feynman's "Photon Hadron Interactions".
 
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Likes Anashim
  • #5
As far as I know, the total cross-sections of the following hadron interactions are well described
by a single Reggeon trajectory and a single Pomeron (soft Pomeron) trajectory.
  1. ##K^-p: (11.93s^{0.0808}+25.33s^{-0.4525})mb##
  2. ##K^+p:(11.93s^{0.0808}+7.58s^{-0.4525})mb##
  3. ##\bar pn:(21.70s^{0.0808}+92.71s^{-0.4525})mb##
  4. ##pn:(21.70s^{0.0808}+92.71s^{-0.4525})mb##
  5. ##p\bar p:(21.70s^{0.0808}+98.39s^{-0.4524})mb##
  6. ##pp:(21.70s^{0.0808}+56.08.39s^{-0.4524})mb##
  7. ##\pi^-p:(11.63s^{0.0808}+36.02s^{-0.4525})mb##
  8. ##\pi^+p:(11.63s^{0.0808}+7.58s^{-0.4525})mb##
  9. ##\gamma p:(0.0677s^{0.0808}+0.129s^{-0.4525})mb##



The last expression is hard for me to understand: in the ##1## to ##20 GeV## range the photon and the proton seem to exchange a Reggeon trajectory and a Pomeron trajectory, although I would tend to think that it should be some kind of Compton scattering. I just don't get it, the only charge a photon sees is the EM charge!! Could anyone, please, offer a reasonable explanation?


Why are these results so unexpectedly accurate? This is a theory I do not particularly like but its results are very precise, specially if you add multiple Pomerons and the Odderon. No other phenomenological model is able to match its results.

These plots can be see in slides number 35 and 36 of the following presentation (from a physicist working at the "KEK Theory Center"):

https://indico2.riken.jp/event/2729/attachments/7480/8729/PomeronRIKEN.pdf
The question is "why does Regge exchange work". Forget about the photon, the scattering is strong-interaction dominated, and would be the same for two neutrons. The QED part is annoying because it doesn't really have a well-defined cross section, because of log-annoyances due to massless photons, people just ignore the charge effects in these cross sections. There is no quantitative theory which can answer this. The best way to understand it qualitatively is that the vacuum in QCD is perturbed by a proton so that there is a cloud of deformation of the vacuum glue and quark condensates, and the protons exchange bound states which define the vacuum deformation. The best reference is Gribov's book "Theory of Complex Angular Momentum", but you should look at all the Regge literature of the late 60s, because this is not covered well anywhere, including later string books.
 
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  • #6
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1970s picture of photon-rho mixing, there is a review by Kurt Gottfried in an early 1970s QED conference hosted at Cornell. It's referenced in Feynman's "Photon Hadron Interactions".

The question is "why does Regge exchange work". Forget about the photon, the scattering is strong-interaction dominated, and would be the same for two neutrons. The QED part is annoying because it doesn't really have a well-defined cross section, because of log-annoyances due to massless photons, people just ignore the charge effects in these cross sections. There is no quantitative theory which can answer this. The best way to understand it qualitatively is that the vacuum in QCD is perturbed by a proton so that there is a cloud of deformation of the vacuum glue and quark condensates, and the protons exchange bound states which define the vacuum deformation. The best reference is Gribov's book "Theory of Complex Angular Momentum", but you should look at all the Regge literature of the late 60s, because this is not covered well anywhere, including later string books.
Ok thank you very much for the info. I will read both books, although I suspect that it's going to take me awhile.
 
  • #7
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1
Me asking about the ##\gamma p## elastic scattering has anything to do with Ron Maimon being banned? I am not aware of having asked anything unrelated to mainstream physics, but if I have, I would be grateful if anybody could tell me what it is, so that, in the future, I can avoid the topic. Moreover, if I have, I guess it's only fair to ban me, not him.
 
Last edited:
  • #8
DrClaude
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Me asking about the ##\gamma p## elastic scattering has anything to do with Ron Maimon being banned? I am not aware of having asked anything unrelated to mainstream physics, but if I have, I would be grateful if anybody could tell me what it is, so that, in the future, I can avoid the topic. Moreover, if I have, I guess it's only fair to ban me, not him.
We do not discuss bans, but I can say that this thread has nothing to do with it.
 

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