Hi Florian,

II'm implementing a U(1)_{Lmu-Ltau} gauge model by assigning distinct charges to the distinct lepton generations. But I'm getting critical errors when calculating vertices. First, when I run

Start[U1-MuTau]

it gives

Checking model files: All files okay

but there is a warning "Particle::unknown: Unknown particle gen1" I am clueless about (see screenshot). Then CheckModel is fine because the warning about Z-Zp mixing is expected, but when running

MakeCHep

Mathematica fully stops at neutrino-neutrino-pseudoscalar vertices

... Generic class: FFS. Expanding and writing: 4/12 . ({Fv[{gt1}],Fv[{gt2}],Ah[{gt3}]})

due to the "large amount of parameters needed". Looking at VertexListFFS.m I notice many lines like

{{Fv[{gt1}], Fv[{gt2}], Ah[{gt3}]},
{(sum[j1, 1, 99, ZNU[gt2, 3 + j1]]*(kem*sum[j2, 1, 99, ZNU[gt1, 4 + j2]]

whose long 1-99 range make me think this is what overloads the CHep output.

Any suggestions?

Best,

For such a model, you should define the three lepton generations as separate fields in the gauge eigenstates, and then combine them in DEFINITION[EWSB][MatterSector]. Then don't forget to add appropriate definitions in the parameters.m and particles.m. But without seeing the model file it's a bit hard to diagnose the problem!

Hi MDGoodsell,

Indeed I separated the distinct generations and edited the particles/parameter files (attached). To avoid clashes I defined all new parameters locally.

The problematic terms are the 3 mass terms for Right-handed Neutrinos (mee, kem, ket). I get the exact same texture as in 1107.5238 Eq.(19), however:

- Including only one mass term takes long but works fine.
- Including two takes much longer and works fine but makes the .mdl files very heavy (~40MB)
- Including all three the evaluation is aborted

Edit: the server is rejecting my attachmets. Hope you don't mind that I sent them to goodsell@lpthe.jussieu.f

Thanks