The Wall Street Journal crossword can be very challenging. But we are here to help! Today we will help you find the answer to the clue Particles composed of a quark and an antiquark. After hunting for any other hints and relevant information in the Wall Street Journal crossword puzzle we've found the answer to the clue Particles composed of a quark and an antiquark. The answer to the clue Particles composed of a quark and an antiquark is: