StringJoin::string: $Failed<> GaugeXi[V[5,___]]=FAGaugeXi["G"]; FAGaugeXi[U[5,___]]=FAGaugeXi["G"]; 中位置 1 处应该是字符串.

[pengfei-physics]

Exause me, When I run the process that requires using GenerateModelQCD.m from FeynRules, it always throws an error, saying ​cannot open FeynRules. this comes from QCD in Example. I want to use PaVe Function to solve some amplititude.

[pengfei-physics]

Hi everyone,

I just realized that the tar.gz file might actually be a compressed archive. After extracting it, I placed the FeynRules folder into the Applications directory. However, I’m still encountering errors when running GenerateModelQCD as well as Gl-GlGl. Could anyone provide guidance on what might be going wrong?

Thanks in advance for your help!

[vsht]

You can't load everything on the same kernel. Different packages are not compatible with each other. Always quit all kernels before you
load any package.

https://feyncalc.github.io/FeynCalcBookDev/Extra/CustomModels.html

BTW, if you're getting a bunch of red error messages, it makes not sense to continue from there. Nothing will work. First fix the errors then go to the next step.

[pengfei-physics]

Dear vsht,

Thank you so much for your help earlier! I’m thrilled that the QCD example is now displaying correctly—your support made a huge difference, and I’m truly grateful.

However, I’ve encountered a new issue when running GenerateModelQCD. It seems that MatrixSymbol is being reported as protected. Could this be due to a potential conflict between FeynRules and Mathematica’s internal definitions? If so, would you kindly advise on how to resolve this?

Thank you again for your time and expertise—it’s greatly appreciated!

Best regards,
pengfei

[vsht]

Yes, I think that MatrixSymbol is now a part of Mathematica's built-in symbols (since version 14.1), while FeynRules uses this object for its own purposes. Presumably older Mathematica versions should not be affected.

Unfortunately, such shadowing conflicts are something that only package developers can fix: They should update the package and
rename conflicting symbols to something else to avoid clashes with Mathematica's definitions.

At this point all you can do is to contact FeynRules people and hope that they provide a fix in a timely manner. Or use an older Mathematica version.

Cheers,
Vlad

[pengfei-physics]

Thank you so much for your prompt and detailed explanation!