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subroutine vvvsxx(ga,gb,gc,sc,g1,g2,vertex)
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c This subroutine computes an amplitude of the coupling of three gauge bosons
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c and a scalar particle
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c complex ga(6) : first incoming vector (gluon)
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c complex gb(6) : second incoming vector (gluon)
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c complex gc(6) : third incoming vector (gluon)
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c complex sc(3) : incoming scalar particle (Higgs)
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c real g1 : coupling constant (QCD)
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c complex g2(2) : coupling constant: gc(1) scalar
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c complex vertex : amplitude
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c-- dimension of the current set to arbitrary length
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include "dimension.inc"
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double complex ga(DIM),gb(DIM),gc(DIM),sc(DIM)
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double complex dvertx, vertex, vertex1, vertex2
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double complex vab, vbc, vca, v123, v124, v134, v234
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double complex pgagb, pgagc, pgbga, pgbgc, pgcga, pgcgb
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double precision pga(0:3),pgb(0:3),pgc(0:3),pabc(4)
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if (g2(1).NE.(0D0,0D0)) then
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vab = ga(1)*gb(1)-ga(2)*gb(2)-ga(3)*gb(3)-ga(4)*gb(4)
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vbc = gb(1)*gc(1)-gb(2)*gc(2)-gb(3)*gc(3)-gb(4)*gc(4)
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vca = gc(1)*ga(1)-gc(2)*ga(2)-gc(3)*ga(3)-gc(4)*ga(4)
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pgagb = pga(0)*gb(1) - pga(1)*gb(2) - pga(2)*gb(3) - pga(3)*gb(4)
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pgagc = pga(0)*gc(1) - pga(1)*gc(2) - pga(2)*gc(3) - pga(3)*gc(4)
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pgbga = pgb(0)*ga(1) - pgb(1)*ga(2) - pgb(2)*ga(3) - pgb(3)*ga(4)
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pgbgc = pgb(0)*gc(1) - pgb(1)*gc(2) - pgb(2)*gc(3) - pgb(3)*gc(4)
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pgcga = pgc(0)*ga(1) - pgc(1)*ga(2) - pgc(2)*ga(3) - pgc(3)*ga(4)
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pgcgb = pgc(0)*gb(1) - pgc(1)*gb(2) - pgc(2)*gb(3) - pgc(3)*gb(4)
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dvertx = vab*(pgagc-pgbgc) + vbc*(pgbga-pgcga) + vca*(pgcgb-pgagb)
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vertex1= dvertx * g2(1)
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if (g2(2).NE.(0D0,0D0)) then
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pabc(1) = pga(0) + pgb(0) + pgc(0)
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pabc(2) = pga(1) + pgb(1) + pgc(1)
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pabc(3) = pga(2) + pgb(2) + pgc(2)
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pabc(4) = pga(3) + pgb(3) + pgc(3)
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v123 = ga(1)*gb(2)*gc(3) - ga(1)*gb(3)*gc(2) - ga(2)*gb(1)*gc(3)
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& + ga(2)*gb(3)*gc(1) + ga(3)*gb(1)*gc(2) - ga(3)*gb(2)*gc(1)
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v124 = - ga(1)*gb(2)*gc(4) + ga(1)*gb(4)*gc(2) + ga(2)*gb(1)*gc(4)
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& - ga(2)*gb(4)*gc(1) - ga(4)*gb(1)*gc(2) + ga(4)*gb(2)*gc(1)
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v134 = ga(1)*gb(3)*gc(4) - ga(1)*gb(4)*gc(3) - ga(3)*gb(1)*gc(4)
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& + ga(3)*gb(4)*gc(1) + ga(4)*gb(1)*gc(3) - ga(4)*gb(3)*gc(1)
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v234 = - ga(2)*gb(3)*gc(4) + ga(2)*gb(4)*gc(3) + ga(3)*gb(2)*gc(4)
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& - ga(3)*gb(4)*gc(2) - ga(4)*gb(2)*gc(3) + ga(4)*gb(3)*gc(2)
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vertex2= g2(2) * ( v123*pabc(4) + v124*pabc(3)
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& + v134*pabc(2) + v234*pabc(1) )
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vertex = g1*sc(1) * (vertex1 + vertex2)