Can you explain to me how the IsElastic-function in the NeyutronTracker works?

I know what an elastic collision between nucleons is, but I do not understand

how you can use those physics to test the clusters.

In particular I am interested in how this function can be modified to also

test for particles that do not come in straight.

I suspect that some of my troubles with the VETO come from the fact that I try to

reconstruct all particles as if they are neutrons. Especially when I have

protons coming in from the side, I suspect that this reconstruction might fail.

Yours Sincerely,

Christiaan Douma.]]>

Can you explain to me how the IsElastic-function in the NeyutronTracker works?

Imagine a neutron did elastic scattering first, and after certain path next interaction. After elastic scattering we have a cluster created by the knocked-out proton, and an arbitrary cluster from second interaction. The goal of this IsElastic function is to eliminate the second cluster, in order that it is not considered as a candidate for first interaction of an incident neutron. By combining start position and angle of one cluster and start position of another, we can decide (based on kinematics), that both were created by the products of the same neutron.

Quote:

In particular I am interested in how this function can be modified to also test for particles that do not come in straight.

The best is to ask Michael Heil, he is the author of this code. But I can hardly imagine such a restriction in the function.

Best regards,

Dima]]>

Christiaan.]]>