That’s not the full explanation; the antiproton is stable (or, is as stable as the proton).
It’s that the net baryon number is 0 and that the flavor ‘quantum numbers’ aren’t conserved by the weak force. If you could turn off the weak force, this cc ubar dbar tetraquark would be absolutely stable.
It’s that the net baryon number is 0 and that the flavor ‘quantum numbers’ aren’t conserved by the weak force. If you could turn off the weak force, this cc ubar dbar tetraquark would be absolutely stable.