Measuring small things (the "zeptoverse")

This physics finding reported on the BBC sounds very cool:

Scientists have picked up signals from the smallest scale of nature ever explored – 100 billion times smaller than an atom.

A world so small that some physicists have nicknamed it the zeptoverse.

Sounds mind boggling.

And apparently this is the actual research paper that reports the findings. It's obviously way above my understanding, but cool to "see" nonetheless!