Some material
All this material it's organised in the Wiki of the Gitlab project.
Material for chi2 fitting:
Material for vertex fitting:
- https://www.nikhef.nl/~wouterh/topicallectures/TrackingAndVertexing/part6.pdf
- https://www.phys.ufl.edu/~avery/fitting/kinfit_talk3.pdf
- most complete for the formulas: http://www.hephy.at/fileadmin/user_upload/Fachbereiche/ASE/Strandlie.pdf
Material for the propagator in uniform B:
Material for Gaussian multiple scattering (7.55, 7.56):
Multiple scattering in the covariance:
Something that I've already presented concerning the Kalman (@sstemmle : just to give an overview):
Geometrical stuff about multiple scattering in the detector simulation: