TABLE OF CONTENTS
/barBar_barBarMes [ Modules ]
NOTES
This module includes the calculation of baryon baryon -> baryon baryon meson cross sections.
barBar_barBarMes/NN_NNpi_direct [ Functions ]
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NAME
function NN_NNpi_direct (srtfree, bg) result(Sigma_NNPion)
PURPOSE
Returns the background contributions to NN-> NN pion (via non-propagated resonances, plus non-resonant part). The pion cross sections contain the following channels:
- 1: p p -> p p pi^0 ; which is equivalent to n n -> n n pi^0
- 2: p n -> n n pi^+ ; which is equivalent to p n -> p p pi^-
- 3: p n -> p n pi^0 ;
- 4: p p -> p n pi^+ ; which is equivalent to n n -> p n pi^-
INPUTS
- real, intent(in) :: srtfree --- sqrt(s) in GeV
- integer, intent(in), optional :: bg --- which background parametrization to use (0=none, 1=Teis, 2=Buss)
OUTPUT
- real, dimension (1:4) :: Sigma_NNPION --- Cross sections in mB
barBar_barBarMes/Np_NRplus_NNPion [ Subroutines ]
[ Top ] [ barBar_barBarMes ] [ Subroutines ]
NAME
subroutine Np_NRplus_NNPion (srtS, background, ch, sigmaDelta, sigma1_2, sigma3_2)
PURPOSE
Evaluates the cross sections for N p -> N Resonance(+) -> N N pion with vacuum assumptions. It returns the cross sections sigma1_2, which is summed over all I=1/2 resonances in the intermediate state, and sigma3_2, which is summed over all I=3/2 resonances in the intermediate state.
INPUTS
- real, intent(in) :: srts ! sqrt(s)
- logical, intent(in) :: background .true. : do not consider any propagated resonances, therefore the background contribution is returned .false. : Consider all resonances, Therefore the full resonance contribution is returned
- integer, intent(in) :: ch ! charge of incoming nucleon
OUTPUT
- real, intent(out) :: sigmaDelta ! the cross section contribution of the Delta resonance
- real, intent(out) :: sigma1_2 ! the cross section summed over all I=1/2 resonances
- real, intent(out) :: sigma3_2 ! the cross section summed over all I=3/2 resonances (except the Delta)
barBar_barBarMes/sstatepi [ Functions ]
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NAME
function sstatepi (srts, mode) result(sigma)
PURPOSE
Function for calculation of N N -> N N pi background (non-resonant), for the following channels:
INPUTS
- real, intent(in) :: srts --- sqrt(s)
- integer, intent(in), optional :: mode --- determines which background parametrization to use
OUTPUT
- real :: sigma(4)
NOTES
- mode=0: no background
- mode=1: background parametrization according to Teis
- mode=2: background parametrization according to Buss Diploma thesis (improves threshold behavior, default)
- mode=3: background parametrization according to Weil
barBar_barBarMes/sig_NNV [ Functions ]
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NAME
real function sig_NNV (srts, ch)
PURPOSE
Cross sections for
1) p p -> p p omega 2) p p -> p p phi 3) p p -> N N pi omega
in mb as function of sqrt(s), according to the parametrization (eq. 15) from Sibirtsev, Nucl. Phys. A 604 (1996) 455.
INPUTS
- real, intent(in) :: srts --- sqrt(s) in GeV
- integer, intent(in) :: ch --- channel selector (1=omega, 2=phi, ...)
NOTE The parameters for channel (1) have been taken from Sibirtsev. The first parameter 'a' has been updated slightly by M. Abdel-Bary et al., Phys. Lett. B 647 (2007) 351. The parameters for channel (2) are from E.Ya. Paryev, J.Phys.G G36 (2009) 015103. The parameters for the third channel have been fitted to results of Pythia 6.4.25 (tuned).
barBar_barBarMes/chooseCharge_NNpiomega [ Functions ]
[ Top ] [ barBar_barBarMes ] [ Functions ]
NAME
subroutine chooseCharge_NNpiomega (chIn, chOut)
PURPOSE
Choose final state charges for N N -> N N pi omega, using Clebsch-Gordan factors which assume the pion is produced via a Delta.
INPUTS
- integer, dimension(1:2), intent(in) :: chIn --- initial state charges (N,N)
OUTPUT
- integer, dimension(1:3) :: chOut --- final state charges (N,N,pi)