Add polarized coeff fnc from 2603.10593

[felixhekhorn]

2603.10593 presents additional massive polarized coeff fncs

[edoardo-spezzano]

Hi Felix (@felixhekhorn),

I have organized the analytic results from arXiv:2603.10593 in a dedicated repository as you suggested: https://github.com/edoardo-spezzano/polarized-coeff-2603.10593