TABLE OF CONTENTS


/initLowPhoton [ Modules ]

[ Top ] [ Modules ]

NAME

module initLowPhoton

PURPOSE

Includes initialization of photon induced events at low energies.


initLowPhoton/pascalTwoPi [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: pascalTwoPi=.true.

PURPOSE

To switch on Pascal's event generator for the gamma N -> N pi pi reaction. .true.=Pascal's prescription ; .false. = phase space


initLowPhoton/equalDistribution_twoPi [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: equalDistribution_twoPi=.false.

PURPOSE

All two pion production channels are populated with the same probability. This enhances the production of pi^0 pi0 pairs. Here, one has been careful to set perweight in a careful manner.


initLowPhoton/twoPi [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: twoPi = .true.

PURPOSE

Switch for the direct 2pi production (gamma N -> N pi pi). If resonances=.true. then it's only a background, else the full cross section. Only works up to sqrt(s) = 2.1 GeV and is set to zero above.


initLowPhoton/vecMes [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: vecMes(1:3) = .false.

PURPOSE

Switch for the production of neutral vector mesons: gamma N -> V N (1=rho^0,2=omega,3=phi)


initLowPhoton/vecMes_Delta [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: vecMes_Delta(1:3) = .false.

PURPOSE

Switch for the production of neutral vector mesons: gamma N -> V Delta (1=rho^0,2=omega,3=phi)


initLowPhoton/resonances [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: resonances = .false.

PURPOSE

Switch for including or excluding resonance production processes.


initLowPhoton/singlePi [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: singlePi = .false.

PURPOSE

Switch for including direct single pion production. If resonances=.true. then it's only a background, else the full cross section. Only works up to sqrt(s) = 2.0 GeV and is set to zero above.


initLowPhoton/pi0Eta [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: pi0Eta = .false.

PURPOSE

Switch for including direct pi^0 eta production. Only works up to sqrt(s) = 2.5 GeV and is set to zero above.


initLowPhoton/pi0Eta=_factor_neutron [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  real, save :: pi0eta_factor_neutron=1.

PURPOSE

Scaling the gamma n->n pi^0 eta cross section. We assume sigma(gamma n->n pi^0 eta)=pi0eta_factor_neutron* sigma(gamma p->p pi^0 eta)


initLowPhoton/fritiof [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: fritiof = .false.

PURPOSE

Switch for including FRITIOF events, cf. 'transitionEvent'. Will not give any contributions below sqrt(s) = 1.7 GeV.


initLowPhoton/includeResonance [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical,save,dimension(1:100) :: includeResonance=.true.

PURPOSE

Switch for including/excluding specific resonances, e.g. includeResonance(21)=.false. excludes the D33(1700).


initLowPhoton/onlyDelta [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical,save  :: onlyDelta=.false.

PURPOSE

Switch for including only delta resonance


initLowPhoton/onlyDelta_not [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical,save  :: onlyDelta_not=.false.

PURPOSE

Switch for excluding only delta resonance


initLowPhoton/debugFlag [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: debugFlag=.false.

PURPOSE

To switch on debugging information


initLowPhoton/energy_gamma [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  real, save :: energy_gamma=0.

PURPOSE

Energy of incoming photon


initLowPhoton/delta_energy [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  real, save :: delta_energy=0.

PURPOSE

Increase of energy for energy scans.


initLowPhoton/energy_weighting [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  integer, save :: energy_weighting = 0

PURPOSE

Determines the relative weighting of different photon energies in energy scans. Possible values:

  * 0 = flat distribution (all energies are weighted equal)
  * 1 = exponential distr. (energies are weighted ~ 1/E)


initLowPhoton/noNucs_twoPi [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: noNucs_twoPi=.false.

PURPOSE

Do not propagate the nucleons which are produced in a 2Pi event.


initLowPhoton/realRun [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: realRun=.false.

PURPOSE

Do not initialize the final state particles as perturbative particles but as real ones.


initLowPhoton/nuclearTarget_corr [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical , save :: nuclearTarget_corr=.true.

PURPOSE


initLowPhoton/makeHist_mass_energy [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save ::  makeHist_mass_energy=.false.

PURPOSE


initLowPhoton/useXsectionBoost [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save ::  useXsectionBoost=.true.

PURPOSE

NOTES


initLowPhoton/selectFrame [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  integer, save :: selectFrame = 1

PURPOSE

Select the frame in which 'sqrt(s)_free' is calulated. 1 = CM frame (default) 2 = LAB frame In the chosen frame, one removes the 0th component of the potential from the nucleon momentum. Then this modified momentum is used to calculate sqrt(s)_free.


initLowPhoton/printXS [ Global module-variables ]

[ Top ] [ initLowPhoton ] [ Global module-variables ]

SOURCE

  logical, save :: printXS = .false.

PURPOSE

Write out the photoproduction cross sections to files lowPhoton_XS.dat and lowPhoton_XS_res.dat.


initLowPhoton/readInput [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

subroutine readInput

PURPOSE

Reads input out of jobcard. Namelist 'low_photo_induced'.


initLowPhoton/low_photo_induced [ Namelists ]

[ Top ] [ initLowPhoton ] [ Namelists ]

NAME

NAMELIST low_photo_induced

PURPOSE

Includes input parameters

Kinematical parameters:

Single Pion production:

Two pion production:

Resonance production:

Vector meson production:

Technical:


initLowPhoton/init_LowPhoton.log [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file init_LowPhoton.log

PURPOSE

Logfile for the lowPhoton init


initLowPhoton/energyWeight [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

real function energyWeight (E)

PURPOSE

Computes a weighting factor which depends on the photon energy. Currently this weighting can be flat or exponential, cf. 'energy_weighting'.

AUTHOR

Janus Weil

INPUTS

NOTES

All weighting functions implemented here should be normalized to the same value, i.e. doing a summation over all energies should yield a value of num_Energies, like in the flat case.


initLowPhoton/initialize_lowPhoton [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

subroutine initialize_lowPhoton (realParticles, pertParticles, raiseFlag, targetNuc)

PURPOSE

AUTHOR

Oliver Buss

INPUTS

NOTES


initLowPhoton/OmegaExcitFunc.dat [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file OmegaExcitFunc.dat

PURPOSE

Contains the omega excitation function, i.e. the energy-dependent inclusive omega photo-production cross section. In contrast to OmegaExcitFunc_pi0gamma.dat, this does not include FSI effects.


initLowPhoton/lowPhoton_XS.dat [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file lowPhoton_XS.dat

PURPOSE

Contains various photoproduction cross sections.

PURPOSE

Columns:

  * 1    : E_gamma [Gev]
  * 2    : sqrt(s) [GeV]
  * 3    : total cross section [mb]
  * 4    : sum of all resonances
  * 5-7  : exclusive pi-, pi0, pi+
  * 8-11 : 2pi
  * 12-20: vector mesons
  * 21   : pi0 eta
  * 22   : Fritiof


initLowPhoton/lowPhoton_XS_res.dat [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file lowPhoton_XS_res.dat

PURPOSE

Contains the resonance photoproduction cross sections.

PURPOSE

Columns:

  * 1 : E_gamma [Gev]
  * 2 : sqrt(s) [GeV]
  * 3-63: resonance cross sections [mb]


initLowPhoton/omegaProdInfo.dat [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file omegaProdInfo.dat

PURPOSE

This file contains informations about omega mesons at production time (event number, perweight, 4-momentum, position, density at production point, etc).


initLowPhoton/omegaProdDensity.dat [ Output files ]

[ Top ] [ initLowPhoton ] [ Output files ]

NAME

file omegaProdDensity.dat

PURPOSE

This file contains a histogram of the density at the production point of omega mesons.


initLowPhoton/twoPiProduction [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

subroutine twoPiProduction(qnuk, momNuk, egamma, sig2Pi,srtFree,betaToCalcFrame,finalState,successFlag)

PURPOSE

INPUTS

RESULT

AUTHOR

Oliver Buss DATE 29/09/2005


initLowPhoton/sigma_1pi_bg [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

subroutine sigma_1pi_bg(targetNuc,phi_pi,theta_pi,q,k_pi,pf_pi)

PURPOSE


initLowPhoton/transitionEvent [ Subroutines ]

[ Top ] [ initLowPhoton ] [ Subroutines ]

NAME

subroutine transitionEvent (nuc, outPart, W, XS, pcm, beta)

PURPOSE

This routine creates inclusive FRITIOF events above E_gamma ~ 1.4 GeV, excluding the exclusive channels N+V and Delta+V, which are treated separately.

It is mainly used for inclusive production of vector mesons, such as V+N+pi, V+N+2pi, V+Delta+pi, V+Delta+2pi, etc.

Cf. Muehlich, Falter, Mosel: Inclusive omega photoproduction off nuclei Eur. Phys. J. A 20, 499-508 (2004)