gibuu is hosted by Hepforge, IPPP Durham
GiBUU

TABLE OF CONTENTS

/pionNucleon [ Modules ]

[ Top ] [ Modules ]

NAME

module pionNucleon

PURPOSE

Includes the cross sections for pion-nucleon scattering in the resonance regime. Implemented are the following reactions:

  • pion nucleon -> X

Public routines:

Public variables:

pionNucleon/matrixDeltaEta [ Global module-variables ]

[ Top ] [ pionNucleon ] [ Global module-variables ]

SOURCE

  real, parameter :: matrixDeltaEta=7.

PURPOSE

Matrix Element for pi N -> eta Delta ; see old "commcoll"->matdeta

pionNucleon/pionNuc [ Subroutines ]

[ Top ] [ pionNucleon ] [ Subroutines ]

NAME

subroutine pionNuc (srts, teilchenIn, mediumATcollision, momentumLRF, teilchenOut, sigmaTot, sigmaElast, plotFlag)

PURPOSE

Evaluates pion Nucleon -> anything cross sections and returns also a "preevent"

This routine does a Monte-Carlo-decision according to the partial cross sections to decide on a final state with maximal 3 (or 4) final state particles. These are returned in the vector teilchenOut. The kinematics of these teilchen is only fixed in the case of a single produced resonance. Otherwise the kinematics still need to be established.

INPUTS

  • real :: srts -- sqrt(s) in the process (free one!!)
  • type(particle),dimension(1:2) :: teilchenIn -- colliding particles
  • type(medium) :: mediumATcollision -- Medium information at the position of the collision
  • real, dimension(0:3) :: momentumLRF -- total momentum in LRF
  • logical, OPTIONAL :: plotFlag -- Switch on plotting of the Xsections

RESULT

  • real :: sigmaTot -- total Xsection
  • real :: sigmaElast -- elastic Xsection
  • type(preEvent),dimension(1:4) :: teilchenOut -- colliding particles

NOTES

Possible final states are :

  • 1-particle : baryon Resonances
  • 2-particle : pi N, omega N, phi N, eta Delta, Kaon Lambda , Sigma Kaon, pion Delta, rho N, rhoDelta, sigma N, pion P11_1440, rho Delta
  • 3-particle : omega pi N, phi pi N, K KBar N, Lambda Kaon Pion, Sigma Kaon Pion
  • Not yet implemented : pi N -> pi pi N which is used for the matching to the high energy region

pionNuc/evaluateXsections [ Subroutines ]

[ Top ] [ pionNuc ] [ Subroutines ]

NAME

subroutine evaluateXsections

PURPOSE

Evaluates all Xsections for pi N scattering

pionNuc/makeDecision [ Subroutines ]

[ Top ] [ pionNuc ] [ Subroutines ]

NAME

subroutine MakeDecision

PURPOSE

Decides on the final state which is returned via teilchenOut by Monte-Carlo. 

  * Assigns charges and ID's. 
  * Only for resonance-production also the mass is assigned, since the mass 
    of the resonance needed to be calculated earlier.

The Monte-Carlo routine is adding up channels until the sum is exceeding x*sigma(total). x has a flat distribution in [0,1]. The last added channel is then the one which is chosen for the event.

pionNuc/makeOutput [ Subroutines ]

[ Top ] [ pionNuc ] [ Subroutines ]

NAME

subroutine makeOutput

PURPOSE

Writes several cross sections to file as function of srts and plab [GeV]. Filenames:

  • 'piN_sigTotElast.dat' : sigmaTot, sigmaElast
  • 'piN_strangeProd.dat' : strangeness production
  • 'piN_resProd.dat' : Baryon resonance production
  • 'piN_nonStrange_nuk.dat' : non-strange meson with nucleon in final state
  • 'piN_nonStrange_delta.dat ' : non-strange meson with delta in final state