Question on Kaons and its strangeness

[Gajan1234]

What is the property of Kaon that make it a strange particle. Other than it takes long to decay but this is same for pion, then why don't we call it a strange particle?


And also what is the exchange particle for strong nuclear force. I thought it Pion, but it is gluon.

 

[mfb]

The pion cannot decay via the strong interaction because it is the lightest hadron, so its long lifetime was well understood. The kaon can decay to pions, so its long lifetime was strange.

And also what is the exchange particle for strong nuclear force. I thought it Pion, but it is gluon.

The gluon is the fundamental exchange particle, but if you want to consider the effective force between (color-neutral) nucleons in a nucleus, pion exchange is a better model.