Thanks for the reading and the questions! It is really appreciated! ;)

Such masses are very hard to imagine. If we cut out a small piece (1 x 1 x 1 cm) from a Neutron Star of 20km radius, this would be roughly 1,780,573,758,736 kg for this 1cm³. I hope I didn't make a miscalculation, there are too many zeros in those numbers. That sounds crazy and impossible, but in reality, it's not even the most massive.

The reality is actually much more complicated than that. Neutron stars are by far not uniform. Whilst the density at the border of the star is 'only' of about 100 tons per cm³, it increases by a factor of 1 billion when one moves towards the center of the star. However, the truth is that whilst we have a good idea of what is going on with the first layers of the star, the central layer is a total unknown and a challenge for theoretical physics (we can see a neutron stars as made of an outer and inner curst, as well an outer and inner core; the inner core is a total mystery for us).

So the Muons will act as a "bridge"that will allow dark matter to interact with detectable matter besides the gravitational force?

Exactly. Dark matter would have, on top of its usual gravitational interactions, an extra direct interaction with muons.

I hope it clarifies!