No difference . Can change the balance a little so on a spring piston rifle it can affect muzzle flip and change the size of the groups a tad for good or bad depending on how you hold, weight of scope etc. A longer barrel also means a longer lock-time, so you need better follow through, shorter can be an advantage.
I believe Bowkett did an experiment couple of decades ago (ish), shortening a barrel till accuracy dropped off, he got down to a few inches.
I always prefer carbines over the standard length, with the exception of the BSA Superstar, (I prefer the balance of the standard gun). Lovely gun, gotta buy anouther...