Passing through an object

[nolanp2]

if the only force preventing one object from pasing through another is caused by electrostatic repulsion of electrons, does this suggest that a neutrino would pass through another neutrino if they were to be fired at each other? could both particles actually exist at the same coordinates?

 

[mathman]

Particles on a subatomic scale can interact by direct collision, although for neutrinoes the cross-section is extremely small.

 

[daniel_i_l]

Like electrons, neutrinos are repelled from one another by paulis exclusion principle - meaning that if two particles are in the same spin state they can't be in the same position state causing them to move apart.

 

[nolanp2]

but doesn't that mean that the particle is being accelerated even without anyone of the four fundamental forces acting on it?

 

[student85]

Someone please answer this guy. This is really interesting.

 

[masudr]

When we look at systems in detail, there is often an "exchange interaction term" in the Hamiltonian that looks like the dot product of the spins of the two objects. See the Wikipedia article on this topic, for instance.

 

[Mentz114]

That term in the Hamiltonian represents a potential, does it not ? It will be zero or some negative value depending on the dot product. It this sufficient to reduce the probablity of finding that state to zero ?

Added later : I've sorted this out, no need to explain.