Question
(a) Verify from its quark composition that the $\Delta^+$ particle could be an excited state of the proton. (b) There is a spread of about 100 MeV in the decay energy of the $\Delta^+$, interpreted as uncertainty due to its short lifetime. What is its approximate lifetime? (c) Does its decay proceed via the strong or weak force? Note: at 2:50 I misspoke saying 10 to the minus "six", when it should have been 10 to the minus "sixteen".
1. See the solution video
2. $3.3\times 10^{-24}\textrm{ s}$
3. Since quark flavor is conserved this decay is probably mediated by the strong nuclear force. The short lifetime of $\approx 10^{-24}\textrm{ s}$ also indicates the strong nuclear force.
Solution Video