I have an exercise for "Introduction to high energy physics" and I'm baffled. The exercise states:

Problem: Higgs particle of mass 125.7 GeV decays in an exclusive channel of baryon-antibaryon (sigma and anti-sigma):

  • Draw a leading order quark diagram for this decay
  • Find in PDG tables the mass of the $\Sigma^0$ baryon and calculate the energy of each of the jets produced in this decay.

My issue: Higgs doesn't seem to have a decay channel into baryon- antibaryon pair in all the resources I looked at. The closest I can get is $H \to b\bar b$ and $H \to c\bar c$ which would eventually create jets if I'm not mistaken. In all other cases, the Higgs decays into bosons or leptons...

Do you think it's a purely hypothetical exercise? Like, calculate things that won't happen? Or am I missing something here?

  • 2
    $\begingroup$ The exercise is asking to just draw the quark level diagram, so just the $H\to \bar q q $ part. The hadronization into baryons happens at a later time. $\endgroup$
    – FrodCube
    Commented Jun 23, 2021 at 14:39
  • $\begingroup$ To add to the above hint, which of the quarks of the Σ does the Higgs couple the strongest to, so, then, decays to? $\endgroup$ Commented Jun 23, 2021 at 16:43
  • $\begingroup$ You have to remember that there are also strange quarks and not only bottom charm and top. see hyperphysics.phy-astr.gsu.edu/hbase/Particles/quark.html $\endgroup$
    – anna v
    Commented Jun 23, 2021 at 18:49

1 Answer 1


The actual Higgs decays are complicated by strong interactions of the quarks involved, but you are asked for a generic question, " if Higgs decays simply to Sigma-Sigma_bar what are the energy relations. This Feynman diagram for tau antitau (the lepton) might make it clear (ignoring athe tau decay)


where the appropriate quark for sigmas takes the place of the tau , and the needed quarks to make the sigma pair introduced.This last can be done by introducing two gluons radiated from the quark pairs going into quark-antiquark, that add up correctly to the quarks needed for sigmas.


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