Important Changes toward Nu Gen 3 Fundamental changes

Important Changes toward Nu. Gen 3 • • Fundamental changes • • • New cross sections New definitions for materials Outgoing neutrino direction for neutral current interaction is supported Technical changes • • Nu. Gen / Genie hybrid mode Injector, Propagator, VTXGenerator

New Cross Sections / Material definitions • The latest Nu. Gen cross section (CSMS) • • • Cross section files for proton and neutron are separated (you may use iso-scalar cross section too) That solves 4% systematics problem due to use isoscalar cross sections for ice, at lower energy Material Definitions • • • [Nu. Gen] NUMBER ratios of proton, neutron and electron are required [Genie] WEIGHT ratio of target atoms (H, O, Si etc. ) are required These numbers are treated in earthmodel-service and end users can use pre-defined materials

Outgoing neutrino direction θCC μ θNC ν CC interaction ν ν NC interaction For NC interaction, θNC was always zero for old Nu. Gen. The effect is expected negligibly small, but I will check it soon.

Technical Changes • Nu. Gen / Genie hybrid mode • • • Use Genie interaction cross section and vertex generator (= interaction driver) if neutrino’s energy is less than an energy threshold (default is 190 Ge. V) You may fix interaction driver via I 3 Nu. GSteering Service (Nu. Gen, Genie, Hybrid. . . ) Injectors • Corsika (mostly copied from Jakob’s module, thanks!) Selects only one neutrino from I 3 MCTree and discards others.

Upgrade plans 1. Fundamental changes 2. Write Injectors 3. Write an interaction driver for Nu. Gen 4. Merge changes to I 3 Neutrino. Generator 5. Comparison with old Nu. Gen Here I am. . . 6. (Release Nu. Gen 2. 8) 7. Port interaction driver for Genie from I 3 Nu. GGenie 8. Rewrite Propagator and Vertex. Generator 9. Release Nu. Gen 3. 0