# How to find Lepton Number? [closed]

is a Standard Model particle with (u, d, b) quark content. What are the electric charge, baryon number and lepton number of this particle? Is this the only particle expected to exist with this quark content? Justify your answer

I know that the overall charge is 0, baryon number is 1. But what is the lepton number? ( The answer is 0) . Why is it 0? Why is it not the only expected particle with this quark content?

## closed as off-topic by John Rennie, DavePhD, Kyle Kanos, David Z♦May 7 '14 at 18:26

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• The leptons are the $e$, $\mu$, $\tau$, and the neutrinos. How many leptons and antileptons are there in a particle made of $u$, $d$, $b$ quarks? – rob May 7 '14 at 16:56
• how do I know which particle do these quarks construct? – user43249 May 7 '14 at 16:58