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## /baryonWidthVacuum [ Modules ]

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NAME

module baryonWidthVacuum

NOTES

Module which calculates the partial and full widths of the baryon resonances in dependence of their mass. Their pole mass is given by their mass in 'particleProperties' and the widths at this pole mass as well. Everything corresponds to the vacuum situation. The resulting width is therefore always the width in vacuum! As mass of the resonance we use the four-vector definition: p_mu p^mu= mass**2 Prescription according to Manley et al. Phys. Rev. D45 (1992) 4002.

## baryonWidthVacuum/interactionRadius [ Global module-variables ]

SOURCE

```  real, parameter, public :: interactionRadius = 1./hbarc
```

PURPOSE

interaction radius for Blatt-Weisskopf functions: r = 1fm

## baryonWidthVacuum/srts_srt_switch [ Global module-variables ]

SOURCE

```  logical, parameter, public :: srts_srt_switch=.false.
```

PURPOSE

Modifies the width according to S. Leupold's definition of the width, one especially has to exchange s against sqrt(s) in the denominator of Formula 2.76 of Effenbergers Phd

## baryonWidthVacuum/deltaRho_cutoff [ Global module-variables ]

SOURCE

```  real, save :: deltaRho_cutoff=0.85
```

PURPOSE

• Cut off parameter for the decay of a resonance into delta rho.
• Units of GeV

## baryonWidthVacuum/meson_cutoff [ Global module-variables ]

SOURCE

```  real, save :: meson_cutoff=1.6
```

PURPOSE

• Cut off parameter for the decay of a resonance into a baryon and an unstable meson.
• Units of GeV

## baryonWidthVacuum/baryon_cutoff [ Global module-variables ]

SOURCE

```  real, save :: baryon_cutoff=2.0
```

PURPOSE

• Cut off parameter for the decay of a resonance into an unstable baryon

and a meson. * Units of GeV

## baryonWidthVacuum/use_cutoff [ Global module-variables ]

SOURCE

```  logical, save :: use_cutoff = .true.
```

PURPOSE

• Switch on and off the use of cut off parameters.
• These cut-offs are necessary when working with dispersion relations to deduce the real part.

## baryonWidthVacuum/Delta_width [ Global module-variables ]

SOURCE

```  integer, save :: Delta_width = 1
```

PURPOSE

Select a parametrization for the Delta width:

• 1 = Manley (GiBUU default, cf. Manley/Saleski, Phys. Rev. D 45, 1992)
• 2 = Dmitriev (Dmitriev/Sushkov/Gaarde, Nucl. Phys. A 459, 1986)
• 3 = Moniz (Koch/Moniz/Ohtsuka, Ann. of Phys. 154, 1984)
• 4 = Verwest (Phys. Lett. B 83, 1979)
• 5 = UrQMD (Bass et al., Prog. Part. Nucl. Phys. 41, 1998)

## baryonWidthVacuum/getParameters [ Subroutines ]

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NAME

subroutine getParameters(a,b,c,flag)

PURPOSE

return the values of ...

## baryonWidthVacuum/readInput [ Subroutines ]

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NAME

PURPOSE

Reads input in jobcard out of namelist "BaryonWidthVacuum".

## baryonWidthVacuum/BaryonWidthVacuum [ Namelists ]

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NAME

NAMELIST /BaryonWidthVacuum/

PURPOSE

Includes the input switches:

## baryonWidthVacuum/monopoleFormfactor [ Functions ]

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NAME

real function monopoleFormfactor(mass,pole,lambda)

PURPOSE

...

## baryonWidthVacuum/vacuumWidth [ Subroutines ]

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NAME

function vacuumWidth (mass, partID, ratio, rho_AB_atPole) result (gammaTotal)

PURPOSE

This routine calculates the total vacuum decay width of a baryonic resonance, i.e. the sum of all partial decay widths, and the branching ratios for each channel as a function of the offshell mass (m^2 = p_mu p^mu). Parameters taken from Manley et al. Phys. Rev. D45 (1992) 4002 and PDG. The mass dependence of the resonances is treated according to Manley.

INPUTS

• real :: mass -- offshell mass of Resonance in GeV
• integer :: partID -- ID of resonance

OUTPUT

• real, dimension(1:nDecays) :: ratio -- branching ratio = partial width / full width for all 2 body decay channels of the baryons
• real, dimension(1:nDecays) :: rho_AB_atPole -- rho_ab(poleMass) of specific decay channel according Effenberger Dr. thesis, eq 2.76
• real :: gammaTotal -- full width in GeV

## baryonWidthVacuum/stableFinalState [ Subroutines ]

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NAME

subroutine stableFinalState (mass, poleMass, mass1, mass2, L, partialWidth_pole, partialWidth_mass, rho_AB_Pole)

PURPOSE

calculate the partial width for the decay into two stable particles. Manley et al. Phys. Rev. D45 (1992) 4002.

NOTES

decay only allowed if:

• (1) decay width>widthCutOff and ...
• (2) mass of resonance > Sum off masses of decay products

INPUTS

• integer :: L -- Angular Momentum
• real :: polemass -- pole mass of mother resonance
• real :: mass -- mass of mother resonance
• real :: mass1 -- mass of first decay product
• real :: mass2 -- mass of second decay product
• real :: partialWidth_pole -- partial width of decayChannel at pole mass

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- Equation 2.76 of Effe Dr. evaluated at pole

## baryonWidthVacuum/Delta_Dmitriev [ Subroutines ]

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NAME

subroutine Delta_Dmitriev (mass, partialWidth_pole, partialWidth_mass, rho_AB_pole)

PURPOSE

Calculate the Delta width according to: Dmitriev/Sushkov/Gaarde, Nucl. Phys. A 459 (1986) 503-524

INPUTS

• real :: mass -- mass of mother resonance
• real :: partialWidth_pole -- partial width of decayChannel at pole mass

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- rho_ab as defined in eq. (2.75) of Effenberger PhD evaluated at pole

## baryonWidthVacuum/Delta_Moniz [ Subroutines ]

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NAME

subroutine Delta_Moniz (mass, partialWidth_pole, partialWidth_mass, rho_AB_pole)

PURPOSE

Calculate the Delta width according to: Koch/Moniz/Ohtsuka, Ann. of Phys. 154 (1984) 99

INPUTS

• real :: mass -- mass of mother resonance
• real :: partialWidth_pole -- partial width of decayChannel at pole mass

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- rho_ab as defined in eq. (2.75) of Effenberger PhD evaluated at pole

## baryonWidthVacuum/Delta_Verwest [ Subroutines ]

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NAME

subroutine Delta_Verwest (mass, partialWidth_pole, partialWidth_mass, rho_AB_pole)

PURPOSE

Calculate the Delta width according to: B.J. Verwest, Phys. Lett. B 83 (1979) 161.

INPUTS

• real :: mass -- mass of mother resonance
• real :: partialWidth_pole -- partial width of decayChannel at pole mass

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- rho_ab as defined in eq. (2.75) of Effenberger PhD evaluated at pole

## baryonWidthVacuum/Delta_Bass [ Subroutines ]

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NAME

subroutine Delta_Bass (mass, partialWidth_pole, partialWidth_mass, rho_AB_pole)

PURPOSE

Calculate the Delta width as used in UrQMD, cf.: Bass et al., Prog. Part. Nucl. Phys. 41 (1998) 255-369.

INPUTS

• real :: mass -- mass of mother resonance
• real :: partialWidth_pole -- partial width of decayChannel at pole mass

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- rho_ab as defined in eq. (2.75) of Effenberger PhD evaluated at pole

## baryonWidthVacuum/semistableFinalState [ Subroutines ]

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NAME

subroutine semistableFinalState (mass, polemass, idStable, idUnstable, L, partialWidth_pole, partialWidth_mass, rho_AB_Pole)

PURPOSE

Calculate the partial width for the decay into one stable and one unstable particle.

Calculates the partial width dependend on mass of a resonance decaying into one stable and one unstable decay product. According to Manley and Effenberger' Dr. Thesis equation 2.76.

INPUTS

• real :: mass -- mass of mother resonance
• real :: polemass -- polemass of mother resonance
• integer :: idUnstable -- ID of unstable decay product
• integer :: idStable -- ID of stable decay product
• integer :: L -- angular momentum of final state
• real :: partialWidth_pole -- partial width at pole of resonance

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_Pole -- Equation 2.76 of Effe Dr. evaluated at pole

## baryonWidthVacuum/rho_AB_Integrand [ Functions ]

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NAME

real function rho_AB_Integrand(mu)

NOTES

This is the integrand of rho_ab(mu) in Effenbergers Dr.-Thesis, page 27, formula 2.76. Only in the case of only one unstable particle!

## baryonWidthVacuum/rhoDeltaFinalState [ Subroutines ]

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NAME

subroutine rhoDeltaFinalState(mass,poleMass,L,partialWidth_pole,partialWidth_mass,rho_AB_atPole)

PURPOSE

Calculate Resonance decays into delta and rho.

INPUTS

• integer :: L -- Angular Momentum
• real :: mass -- mass of resonance
• real :: partialWidth_pole -- partial widht of decayChannel at pole mass
• real :: poleMass -- pole mass of resonance

OUTPUT

• real :: partialWidth_mass -- partial width at real mass
• real :: rho_AB_atPole -- Equation 2.76 of Effe Dr. thesis evaluated at pole mass

## rhoDeltaFinalState/deltaRho [ Functions ]

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NAME

function deltaRho (srts, ang, flag) result (integral)

NOTES

This routine calculates the integral of the Delta rho final state It calculates rho_AB as quoted in equation 2.76 in Effenbergers Dr. thesis