in case any1 is an enthusiast in solving basic exercises involving the Higgs boson in its interaction with fermions he/she can avail prerequisite drills involving analogous setup since it is basically Yukawa interaction, these on pages 312-318, Lectures on Quantum Field Theory, Ashok Das,
https://books.google.com.ph/books?id=7AX38Cqeg3kC&lpg=PR9&pg=PR3#v=onepage&q&f=false
Follow
those pages guide me in consideting this basic exercise although I have slightly different notations and style but must you check my work
https://foxtrotpaparomeo.wordpress.com/2023/01/11/12012023first-order-calculations-of-the-probability-amplitude-for-higgs-boson-to-electron-positron-decay/
