sentences:  In this notation, the superscript character indicates whether the particle is electrically neutral (0) or carries a positive charge (+).The subscript character, or its absence, indicates whether the third quark is a strange quark (no subscript), a charm quark , a bottom quark , or a top quark .Physicists do not expect to observe a Lambda baryon with a top quark because the Standard Model of particle physics predicts that the mean lifetime of top quarks is roughly seconds; that is about of the mean timescale for strong interactions, which indicates that the top quark would decay before a Lambda baryon could form a hadron.