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/twoBodyPhaseSpace [ Modules ]

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NAME

module twoBodyPhaseSpace

NOTES

Includes all the routines which are necessary for the two-body phase-space.

twoBodyPhaseSpace/setMaxSqrts [ Subroutines ]

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NAME

subroutine setMaxSqrts(srtsMax)

PURPOSE

set the upper bound of the tabulation

twoBodyPhaseSpace/Integrate_2bodyPS_resonance [ Functions ]

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NAME

function Integrate_2bodyPS_resonance (resID, srts, massStable, scalarPotential) result (ps)

PURPOSE

Returns Integral over the CM-momentum with a resonance among the two particles. Therefore one has to Integrate over the mass of the resonance as well:

```    ps=Integral { p_final(m_R) * Spectral function(m_R} d(m_R)
```

with

```    m_R = massResonance
```

It uses an internal routine "Calculate" which is either called directly or we store its values to a field.

This routine is not giving the real Phase space !!!

INPUTS

• integer, intent(in) :: resID -- Id of the resonance
• real, intent(in) :: srts -- sqrt(s) in the problem
• real, intent(in) :: massStable -- mass of the stable particle
• real, intent(in) :: scalarPotential -- scalarPotential of the resonance

OUTPUT

• real,dimension(1:5) :: ps -- Integral as given above

Here the different components are:

• ps(1): With full width evaluated in the nominator of spectral function
• ps(2): With partial width (pion N) evaluated in the nominator of spectral function
• ps(3): With partial width (eta N) evaluated in the nominator of spectral function
• ps(4): With partial width (rho N) evaluated in the nominator of spectral function
• ps(5): With partial width (omega N) evaluated in the nominator of spectral function

NOTES

Formerly known as "massInt2"

twoBodyPhaseSpace/nnRR [ Subroutines ]

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NAME

real function nnRR (srts, ID)

PURPOSE

Procedure for calculation of integrals of Resonance Resonance' CM-momentum

Evaluates Integral over two body phase space in vacuum for two baryon resonances. Therefore one has to Integrate over the mass of the two resonances as well.

```    ps=Integral d(mass_A )  d(mass_B ) p_AB * Spectralfunction_A Spectralfunction_B
```

INPUTS

• integer :: ID(1:2) -- Ids of the resonances
• real :: srts -- sqrt(s) of the reaction

OUTPUT

• Integral as given above

NOTES

To increase speed, we tabulate the possible output for Delta+R.