Neutrino yield

What do we expect to look for

Same script nu_yield.C as in the SHiP original study.

First study, mass 1 ton, size 40 x 40 square cm

Then, moved to mass 4.5 ton, size 40 x 80 square cm

The distance is considered with respect to the start of the main SHiP target, ship_geo.target.z0

with respect to the middle of SND target along z

Options under study

Check target configuration

The main parameters of this study are:

• Transverse size (dx, dy);

• Material density;

• Total mass (which gives you volume from density and then, assuming a box shape, gives you dz);

• Distance from proton target (see above)

Transverse size and distance are required for generate_neutrinos(), which propagates the fluxes to neutrino detectors and cuts away the ones outside acceptances;

Transverse size, mass and atomic number (material), are needed for nu_yield(), which computes the number of expected interactions for the different neutrino channels

Checking different neutrino sources

What are the sources?

3 different files:

• no charm production, option 0;

• only charm production, option 1;

• with charm production, option 2 (ideally, should be the sum of the above);

If no option is provided, the total one (option 2) is used.

The code workflow is:

• Create a link to /eos/experiment/ship/data/Mbias/background-prod-2018/pythia8_Geant4_1.0_withCharm_nu.root and to /eos/user/a/aiuliano/public/sims_FairShip/GenieEvents_SHIP/SplinesTungstenSHIP/nu_xsec_TungstenSHIP.root

• Create an empty folder, called plots_2;

• Launch generate_neutrinos() or generate_neutrinos(2);

• Launch nu_yield() or nu_yield(2);

• Normalize neutrino rates, initially 5e+13, to 2e+20 pot per target. From ECN3 onwards normalized per year, 4e+19 protons on target. SpreadSheet can help with that, but always check what you paste

• Backup the output to EOS if needed.

Note: recently (2024) we added also the splines for Iron, due to the studies for implementation of AdvSND target in SHiP@ECN3

To do: check also the 10 GeV file, set links automatically in script

With respect to detector size

With the same mass, what changes with different transverse sizes?

Creating a folder for each configuration

With respect to detector angular position

Changing TX offset, telling us center position

Again, a folder for each configuration

Created a separate nu_yield_angles.C to check different angles

Neutrino Simulation

Since GENIE changed, I would need to redo the splines.

For now, still using old splines, and regenerating neutrino interactions with old GENIE.

After SHiP approval, modernization should be performed (See Oliver discussion)