No, it's not surprising theoretically, but experimentally it's still quite an achievement to be able to spot even these rare events.

It was a bit of an open question what would happen with the heavy charm quarks, given that they each mass more than the entire proton, but yeah... anything else would have been a major surprise.

From the article's description it sounds like they tortured the data until it told them what they wanted. If the charm did show up, how long did it exist? In conventional spectroscopy, the broader the line, the shorter the lifetime (and v.v.) It smells like a sub-attosecond lifetime, if that.

What’s interesting is that there’s a net charm content: there are more charm quarks to be found than anti-charms.

Given that charm quarks are heavier than the proton, you’d expect to only find them in deep inelastic collisions when they are produced in pairs with an anti-quark, so it is surprising that there’s an asymmetry.

Wait, what? I read the article as saying that it's an open question whether there's a charm asymmetry.