How can the Down Quark be studied more if it cannot be isolated ?

On 8/3/2022 at 11:43 PM, PeterSeeksKnowledge said:

Down quarks themselves cannot be the source of gravity, but there may be something in the proportion of down quarks to up quarks in a particular type of matter that somehow affects the binding energy present in that matter.

And what is the ratio of down quarks to other quarks in the case of photons, which are certainly coupled to gravity? 0/0?

20 hours ago, PeterSeeksKnowledge said:

How can the Down Quark be studied more if it cannot be isolated ?

You can’t isolate it (the concept of a single quark doesn’t even make sense), but you can probe its properties by letting it interact with other particles, even while it is bound up in a composite particle. This technique is called deep inelastic scattering.