Take a field that requires a PhD to work in, purports to do research, has multiple journals with peer-reviewed publications, runs multiple conferences...

Let me remind you of the Feynman's description:

I think the educational and psychological studies I mentioned are examples of what I would like to call cargo cult science. In the South Seas there is a cargo cult of people. During the war they saw airplanes with lots of good materials, and they want the same thing to happen now. So they've arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head to headphones and bars of bamboo sticking out like antennas--he's the controller--and they wait for the airplanes to land. They're doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn't work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they're missing something essential, because the planes don't land.

As to

would you characterize a field like that as art or science?

Neither. I would call it mental masturbation.

All of these are plausibly true of art departments at universities as well. (The first two are a bit iffy.)