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c********************************************************************
c...dotup()-------dot product of two momentum. c
c...polsppup()----spinnor product involving bc* polarization vector. c
c...inpup()-------inner product of two massless partical. c
c...sppup()-------spinor product of <p1+|\slash(p3)|p2+>. c
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
c... bc in color-singlet and color-octet states. c
cccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
c...dotproduct of two momenta.
double precision function dotup(ip,jp)
implicit double precision (a-h,o-z)
implicit integer (i-n)
double complex colmat,bundamp
common/upcom/ecm,pmbc,pmb,pmc,fbcc,pmomup(5,8),
& colmat(10,64),bundamp(4),pmomzero(5,8)
dotup=pmomup(4,ip)*pmomup(4,jp)-pmomup(1,ip)*pmomup(1,jp)-
& pmomup(2,ip)*pmomup(2,jp)-pmomup(3,ip)*pmomup(3,jp)
return
end
c******************************************************************
c...inner product involving bc polarization vector. ip stands one
c...of the three polarization vectors.
double complex function polsppup(ip)
implicit double precision (a-h,o-z)
implicit integer (i-n)
double complex colmat,bundamp,piv,pjv,ephase,pkv
common/upcom/ecm,pmbc,pmb,pmc,fbcc,pmomup(5,8),
& colmat(10,64),bundamp(4),pmomzero(5,8)
common/pol/polar(4,3)
pia=polar(4,ip)+polar(3,ip)
pip=polar(4,ip)-polar(3,ip)
piv=dcmplx(polar(1,ip),polar(2,ip))
pja=pmomup(4,8)+pmomup(3,8)
pjp=pmomup(4,8)-pmomup(3,8)
pjv=dcmplx(pmomup(1,8),pmomup(2,8))
pka=pmomzero(4,3)+pmomzero(3,3)
pkp=pmomzero(4,3)-pmomzero(3,3)
pkv=dcmplx(pmomzero(1,3),pmomzero(2,3))
if (pja .gt. 1.0d-16 .and. pjp .gt. 1.0d-16) then
ephase=dconjg(pjv)/dsqrt(pja*pjp)
else
ephase=dcmplx(1.0d0)
end if
polsppup=pka*pip*dconjg(pjv)-dconjg(pkv)*pja*pip-pka*piv*pjp
& *ephase**2+piv*dconjg(pkv)*dconjg(pjv)-pkv*dconjg(piv)*
& dconjg(pjv)+pja*dconjg(piv)*pkp+pia*pkv*pjp*ephase**2-
& pia*pkp*dconjg(pjv)
return
end
c*****************************************************************
c...inner scalar product of two momenta.
double complex function inpup(ip,jp)
implicit double precision (a-h,o-z)
implicit integer (i-n)
double complex colmat,piv,pjv,bundamp
common/upcom/ecm,pmbc,pmb,pmc,fbcc,pmomup(5,8),
& colmat(10,64),bundamp(4),pmomzero(5,8)
c-ap initialize to avoid compiler warming:
inpup = 0.
c-ap end init
pia=pmomzero(4,ip)+pmomzero(3,ip)
pip=pmomzero(4,ip)-pmomzero(3,ip)
piv=dcmplx(pmomzero(1,ip),pmomzero(2,ip))
pja=pmomzero(4,jp)+pmomzero(3,jp)
pjp=pmomzero(4,jp)-pmomzero(3,jp)
pjv=dcmplx(pmomzero(1,jp),pmomzero(2,jp))
if (pia .gt. 1.0d-16 .and. pja .gt. 1.0d-16) then
inpup=piv*dsqrt(pja/pia)-pjv*dsqrt(pia/pja)
end if
if (pia .lt. 1.0d-16 .and. pja .gt. 1.0d-16) then
inpup=dsqrt(pip*pja)
end if
if (pia .gt. 1.0d-16 .and. pja .lt. 1.0d-16) then
inpup=-dsqrt(pia*pjp)
end if
if (pia .lt. 1.0d-16 .and. pja .lt. 1.0d-16) then
inpup=0.0d0
end if
return
end
c******************************************************************
c...spinor product <p1+|\slash(p3)|p2+>, all momenta are light-like.
double complex function sppup(ip,kp,jp)
implicit double precision (a-h,o-z)
implicit integer(i-n)
double complex colmat,inpup,bundamp
common/upcom/ecm,pmbc,pmb,pmc,fbcc,pmomup(5,8),
& colmat(10,64),bundamp(4),pmomzero(5,8)
sppup=dconjg(inpup(kp,ip))*inpup(kp,jp)
return
end
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