Why 'Shielding' is recommended for underground physics?

Physics Lists
1

Dear Experts,

I found that GEANT4 recommends Shielding physics list for underground physics application. I would highly appreciate it if you could let me know the reason(s) for this suggestion and also if there are articles available which describe this.

Thanks and regards,
Samir

2

Because underground physics is typical backgrounds limited, and involves lower energy background sources. The Shielding physics list includes NeutronHP, so you get better results for low-energy neutron interactions in your shielding and detector materials.