re the header it is part of my studies in SM, working on basic practice calculations
https://foxtrotpaparomeo.wordpress.com/2022/09/29/29092022-updatesfirst-order-calculations-of-the-probability-amplitude-for-higgs-boson-to-electron-positron-decay/
the recent typos have just been corrected, those concerning the vector gauge boson masses in (20.9.9.4)
https://foxtrotpaparomeo.wordpress.com/2022/11/22/22112022-updatesfirst-order-calculations-of-the-probability-amplitude-for-higgs-boson-to-electron-positron-decay/