In a recent question Can colliders detect B violation? I asked about detecting B violation in collisions. Here I am interested in the theory aspect. (I asked both questions originally in the same question, but I got one answer which was more on the experimental side, and I don't think the two domains of expertise overlap enough to keep the questions merged. I am also interested in the purely theoretical question)

What is the rate of B violation expected in the standard model in high energy proton-proton or proton-anti-proton collisions? The rate is known to be vanishingly small at ordinary temperatures and energies, but this is because the instantons that cause the effect are suppressed by the Higgs. At high temperatures, the effect is believed to be significant, but this doesn't mean it is significant in 2 body collisions.

Is it also significant at high energy collisions? I have seen arguments that localized 2-body collision cannot produce an instanton-like configuration (I don't remember the exact paper), but I am not sure if this conclusion is trustworthy.

What is the rate of B violation for parton collisions in the standard model? Is it always negligible?

  • $\begingroup$ Here is a theoretical estimate using a supersymmetric model: arxiv.org/pdf/1204.4458.pdf . The 125 Higgs gamma gamma channel probably disproves the model. They focus on the change in signatures to look for SS particles due to B and L violation (no large missing masses) $\endgroup$ – anna v Jul 15 '12 at 7:07
  • $\begingroup$ @annav: This type of thing is not what I was asking about. This is perturbative B violation due to extra particles. I just want the nonperturbative B violation in the standard model itself, which is very weak, and to know whether it becomes noticible in high energy collisions, without extra matter. $\endgroup$ – Ron Maimon Jul 15 '12 at 8:09
  • $\begingroup$ Not competent to answer your question, but some possibly useful references here $\endgroup$ – twistor59 Jul 15 '12 at 8:30
  • $\begingroup$ fair enough. It seems 't Hooft tackled this non perturbative component (at tree level B and L are "accidentally" conserved) G. 't Hooft, Phys. Rev. Lett. 37, 37 (1976); Phys. Rev. D14, 3432 (1976) . Got the reference from ned.ipac.caltech.edu/level5/Sept03/Trodden/Trodden4_9.html . $\endgroup$ – anna v Jul 15 '12 at 10:52
  • $\begingroup$ arxiv.org/abs/hep-ph/0212099 seems relevant. $\endgroup$ – mmc Jul 15 '12 at 16:03

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