I have been doing baryonic CPV experimental search in the past few years. However, I never really get a good clue on this fundamental question.
The thing is that CPV has only been found in the meson sector. The reason driving us to search for baryonic CP violation is to find new source of CPV to explain the large matter-antimatter asymmetry in our universe and to satisfy Sakharov conditions.
According to current research results, even if baryonic CPV does exist, it can only be about sub-percent level or even smaller. How can this level of asymmetry explain that our universe is dominated by matter rather than anti-matter?
I know that baryonic CPV is a necessary requirement for baryon asymmetry to exist. But how can such a small CPV explain such large asymmetry?
In the past, I thought it may come from something that happened in the early stage of the universe. Suppose that in the early condensed quark epoch stage of universe, we have a baryonic CPV of 0.1%, 1001 baryon and 1000 anti-baryon. 1000 baryon-antibaryon pairs annihilated and emit 2000 photons, thus what's left today will be 2000 photons and 1 proton (stable decay remain of the 1 baryon that didn't annihilate). This gives me a good, phenomenal picture of why there are so many photons in the universe and why protons rather than anti-proton have dominated amount.
Tim Gershon gave me a good explanation in a report last year. Unfortunately, I forgot his answer.
