Conservation of Strangeness (outside of strong interactions)

[OJFord]

I realize that strangeness must only be conserved in strong interactions,

but if strangeness is conserved, must it be a strong interaction?I'm an A level student so please go easy.. mention spin, colour, charm, top or bottom and I'll know not where to look.

 

[fzero]

I realize that strangeness must only be conserved in strong interactions,

but if strangeness is conserved, must it be a strong interaction?


I'm an A level student so please go easy.. mention spin, colour, charm, top or bottom and I'll know not where to look.

The electromagnetic interaction also conserves strangeness (conserves quark and lepton flavor in general), so no. Without specifying more details, we can't possibly determine which interactions are involved.

To complicate matters further, there are also weak interactions that conserve strangeness. If you know of the W and Z bosons, then interactions which involve exchange of W bosons change the flavor of quarks and leptons, while those that involve Z bosons do not.

 

[OJFord]

Excellent, thank you.

My textbook was just ambiguously worded - I wasn't sure if strangeness was only conserved in strong interactions, or if (as is the case) it's only in strong interactions that strangeness must be conserved.

You're answer clears that up, thanks.

 

[mfb]

Simple example: There are many processes of the weak interaction without any strange quarks, so strangeness is 0 all the time, which means that it is conserved.

The weak interaction can violate strangeness (and all other interactions cannot), but it does not have to. The same is true for the other similar quantum numbers (charm, top, bottom - they are the same as strangeness, just for other quarks).