Barns have physical dimensions of area, even though they are used to express probability distributions. So you can imagine “the broad side of a barn” as being so many square meters, but then scale it way way down to a particle physics equivalent, and you get the barn. Which apparently roughly represents “the broad side of a uranium nucleus”.
The probability of interaction between a nuclei and a particle is called a “barn” - because its a bit like shooting the broad side of a barn.
Its a standard Sci unit, too, so real actual papers will use “megabarn” as a real unit of measure.
Its subunit is called a “shed”, because physicists don’t get out enough.
One of the key enzymes in electrical signaling in your brain is called Pikachurin
Barns have physical dimensions of area, even though they are used to express probability distributions. So you can imagine “the broad side of a barn” as being so many square meters, but then scale it way way down to a particle physics equivalent, and you get the barn. Which apparently roughly represents “the broad side of a uranium nucleus”.
I actually like the barn as a unit of measure.
I am forever haunted by the decision decades ago to refer to two of the quarks as Top and Bottom. Maybe it was cute at the time. It did not age well.