Not really a pun, but along the lines of "...walked into a bar..." jokes and science jokes, why not? The neutrons say "Here ever were we notice even won't you. Through passing just we're, okay it's." The bartender says "We don't serve your types around here." Two neutrinos walk into a bar. (This joke is sort of dense) Two chemists walked into a bar. The first said "I would like an H2O." The second, rest his soul, said "I would like an H2O, too." A Higgs Boson walks into a church and says "Wait, you can't have mass without me!" In my opinion, absolute zero is just OK. He'd better keep an ion that.