# Tag Info

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Dear Chad, you misinterpret the statement that "the known sources of CP-violation are not enough to explain the matter-antimatter asymmetry in the Universe." You seem to think that the statement means that the known CP-violating parameter (namely the CP-violating phase in the CKM matrix) and the processes based on it are qualitatively insufficient to ...

7

Good question! Regarding (2) baryon number is certainly violated at Planckian energies. If you can make a black hole, you can eat up baryons. Luboš Motl's argument that you linked to is correct in this regard. Whether you can make a believable scenario of quantum gravity driven baryogenesis at the Planck time is up in the air as far as I know. It's the old ...

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The LHC depends in large measure on it's huge luminosity for its usefulness. Making anti-proton beams is hard, and making them at high luminosity is harder still. While there are advantages to $p\bar{p}$, they are not overwhelming and the luminosity issue drives all.

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To achieve a nonzero baryon asymmetry, one needs to satisfy the so-called Sakharov conditions: Baryon $B$ violation C-symmetry violation and CP-symmetry violation Interactions out of thermal equilibrium If at least one of these "asymmetries" or "imbalances" is missing, the total $B$ of the Universe will remain zero. The Standard Model preserves $B$ ...

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In reply to the second partenthetical question, I wrote that matter created from energy in particle physics experiments is "generally" in the form of particle-antiparticle pairs . This is too restrictive. Quantum numbers have to be conserved, and they are conserved in pair production, but there can also be associated production of mesons etc: For example ...

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I'd like to point out that there is a small probability that the assumption on which the question is based: "As I hope is obvious to everyone reading this, the universe contains more matter than antimatter," may not be true, depending on the result of the Aegis experiment at CERN. That's because, as Professor Orzel stated in his answer to this ...

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Recreating the conditions of the early universe is a popular explanation, not an exact statement of what is happening at the LHC. It was never the primary goal of the LHC to produce anything similar to conditions in the early universe. To whatever extent it does so, that's just a side benefit of the searches for the Higgs boson and supersymmetry. Besides, ...

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The only source of asymmetry in the Standard Model is from CP violation, and although there is CP violation in the Standard Model it is not large enough to account for the observed asymmetry. It's expected that the asymmetry will be explained by some extension to the standard model, but at the moment we don't know which, if any, of the suggested extensions ...

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