FHCouplings


       FHCouplings  - compute the Higgs couplings, decay widths, and branching
       ratios

       #include "FHCouplings.h"

       integer error
       double complex couplings(ncouplings), couplingsms(ncouplingsms)
       double precision gammas(ngammas), gammasms(ngammasms)
       integer fast

       subroutine FHCouplings(error,
         couplings, couplingsms,
         gammas, gammasms, fast)

       FHCouplings[fast:1]

       FHCouplings computes the Higgs couplings, decay widths,  and  branching
       ratios.   It uses the Higgs masses and mixings computed during the last
       invocation of FHHiggsCorr(1).  The flags and parameters must have  been
       set before with FHSetFlags(1) and FHSetPara(1)/FHSetSLHA(1).

       The arrays passed to FHCouplings should never be accessed directly, but
       only through the preprocessor macros defined  in  FHCouplings.h,  which
       needs to be included once per file.

       error (output)
              zero  if  successful,  otherwise  the line number in Couplings.F
              from which the error message was emitted

       couplings(i) (output)
              the MSSM Higgs couplings.  This array is indexed with preproces-
              sor macros (see below).

       couplingsms(i) (output)
              the  couplings  of  a Standard Model Higgs with the same mass as
              the respective MSSM Higgs.  This  array  is  indexed  with  pre-
              processor macros (see below).

       gammas(i) (output)
              the  Higgs  decay  widths  and  branching ratios.  This array is
              indexed with preprocessor macros (see below).

       gammasms(i) (output)
              the decay widths and branching ratios of a Standard Model  Higgs
              with  the same mass as the respective MSSM Higgs.  This array is
              indexed with preprocessor macros (see below).

       fast (input)
              a flag indicating whether the off-diagonal fermion decays  shall
              be  computed.   Unless  the  decays  h_i -> f_j f_k (j != k) are
              explicitly needed, they may safely be ignored,  as  they  hardly
              contribute to the total cross-section.

       The total decay widths are accessed as

       GammaTot(h)
              the total width of the (MSSM) Higgs boson, where
              h = 1..4  Higgs: h0, HH, A0, Hp

       GammaSMTot(h)
              the  total  width  of a Standard Model Higgs boson with the same
              mass as the respective MSSM Higgs boson, where
              h = 1..3  Higgs: h0, HH, A0

       The following macros access couplings, widths, and branching ratios:

       Coupling(c)
              the coupling for the scalar or vector channel c

       LCoupling(c), RCoupling(c)
              the left- and right-handed couplings for the  fermionic  channel
              c, i.e. the coupling is
                              1 - gamma_5                1 + gamma_5
                 LCoupling(c) ----------- + RCoupling(c) -----------
                                   2                          2
              Equating  this  to S + i gamma_5 P, the scalar and pseudo-scalar
              coefficients are trivially obtained as
                 scalar = 1/2 (RCoupling(c) + LCoupling(c)),
                 pseudo-scalar = 1/(2 i) (RCoupling(c) - LCoupling(c)).

       The couplings are given in the conventions of the MSSM  model  file  of
       FeynArts.   For  couplings  where the order is essential, the following
       rules apply:
       - A charged Higgs at pos. 1 is always the particle, i.e. H-,
         this fixes all other particles by charge conservation.
       - For the H0ChaCha coupling, the first Chargino is the
         particle, chi-, and the second one the antiparticle, chi+.

       CouplingSM(c), LCouplingSM(c), RCouplingSM(c)
              the coupling for the corresponding SM channel.

       Gamma(c), BR(c)
              the width and branching ratio for channel c.

       GammaSM(c), BRSM(c)
              the width and branching ratio of the corresponding SM channel.

       H0VV(h,vv)
              neutral Higgs to vector + vector, where
              h  = 1..3  Higgs: h0, HH, A0
              vv = 1..5  vector-boson pair:
                         gamma gamma, gamma Z, ZZ, WW, gg

       H0FF(h,t,g1,g2)
              neutral Higgs to fermion + fermion, where
              h  = 1..3  Higgs: h0, HH, A0
              t  = 1..4  fermion type: nu, e, u, d
              g1 = 1..3  fermion generation
              g2 = 1..3  fermion generation

       HpFF(p,g1,g2)
              charged Higgs to fermion + fermion, where
              p  = 1..2  decay products: leptons, quarks
              g1 = 1..3  up-type fermion 1 generation
              g2 = 1..3  down-type fermion 2 generation

       H0ChaCha(h,c1,c2)
              neutral Higgs to chargino + chargino, where
              h  = 1..3  Higgs: h0, HH, A0
              c1 = 1..2  chargino 1
              c2 = 1..2  chargino 2

       H0NeuNeu(h,n1,n2)
              neutral Higgs to neutralino + neutralino, where
              h  = 1..3  Higgs: h0, HH, A0
              n1 = 1..4  neutralino 1
              n2 = 1..4  neutralino 2

       HpNeuCha(n1,c2)
              charged Higgs to neutralino + chargino, where
              n1 = 1..4  neutralino
              c2 = 1..2  chargino

       H0HV(h,hv)
              neutral Higgs to Higgs + vector, where
              h  = 1..3  decaying Higgs: h0, HH, A0
              hv = 1..3  produced pair: h0-Z, HH-Z, A0-Z

       HpHV(hv)
              charged Higgs to Higgs + vector, where
              hv = 1..3  produced pair: h0-W, HH-W, A0-W

       H0HH(h,h1,h2)
              neutral Higgs to Higgs + Higgs, where
              h  = 1..3  decaying Higgs: h0, HH, A0
              h1 = 1..4  produced Higgs 1: h0, HH, A0, Hp
              h2 = 1..4  produced Higgs 2: h0, HH, A0, Hp

       H0SfSf(h,s1,s2,t,g)
              neutral Higgs to sfermion + sfermion, where
              h  = 1..3  Higgs: h0, HH, A0
              s1 = 1..2  sfermion 1
              s2 = 1..2  sfermion 2
              t  = 1..4  sfermion type: nu, e, u, d
              g  = 1..3  common sfermion generation

       HpSfSf(s1,s2,p,g1,g2)
              charged Higgs to sfermion + sfermion, where
              s1 = 1..2  up-type sfermion 1
              s2 = 1..2  down-type sfermion 2
              p  = 1..2  decay products: sleptons, squarks
              g1 = 1..3  up-type sfermion 1 generation
              g2 = 1..3  down-type sfermion 2 generation

       Mathematica and Fortran share the same names for the channels, but  due
       to  the  structure  of  the  Mathematica output, the results have to be
       accessed in a slightly different way.

       To access the h0 -> top top decay, for example, one would use

         couplings = FHCouplings[];
         h0ff = Gamma[H0FF] /. couplings;
         h0toptop = h0ff[[1,3,3,3]]

       in Mathematica, while in Fortran the same is done with

         call FHCouplings(error, couplings, gammas, gammasms)
         h0toptop = Gamma(H0FF(1,3,3,3))

       libFH(1)

                                  11-May-2012                   FHCOUPLINGS(1)