∫θo01cos4(θ)e−xaecos(θ)d(cos(θ))
is an interesting one. And has solution,
z=cos(θ)
∫θo01z4e−xaezdz=1z4{xaeEi(−xaez)+xe−xaez}+c
where Ei(x) is the polyexponential function,
OR
ae(x2+2aexz+2a2ez2)x3z2e(−xaez)
And so,
∫θo01cos4(θ)e−xaecos(θ)d(cos(θ))=[aex3cos2(θ){x2+2aexcos(θ)+2a2ecos2(θ)}e(−xaecos(θ))]θo0
Which has a DC term,
aex3{x2+2aex+2a2e}e(−xae)
This term suggests that the B field is always present and the positively charged nucleuii are held permanently in the B orbits.
1/x^4*e^(-a/(2*x)) for 0.5≤a≤5, 1/x^4*e^(-2.5/(2*x)), and 1/x^5*e^(-2.5/(2*x)) are plotted below.
Since, x=cos(θ), x≤1 the graph 1x5>1x4. And
1x4ea/(2x) increases with decreasing a which in our original expression is x, the distance between the center of the loop and the orbiting negative charge.