TABLE OF CONTENTS
/resonanceCrossSections [ Modules ]
NAME
module resonanceCrossSections
PURPOSE
Includes all routines to evaluate "baryon meson -> R -> X" cross sections with resonances R in the intermediate state.
resonanceCrossSections/fullPropagator [ Global module-variables ]
[ Top ] [ resonanceCrossSections ] [ Global module-variables ]
PURPOSE
Includes also the real parts in the resonance propagator. In former works (i.e. in the old Efffenberger code) this has been neglected. It should be set to .true. only if mediumSwitch_coll=.true. in the namelist width_Baryon.
SOURCE
logical, save :: fullPropagator=.false.
resonanceCrossSections/ResonanceCrossSections [ Namelists ]
[ Top ] [ resonanceCrossSections ] [ Namelists ]
NAME
NAMELIST ResonanceCrossSections
PURPOSE
Includes parameters:
resonanceCrossSections/resonanceMass [ Functions ]
[ Top ] [ resonanceCrossSections ] [ Functions ]
NAME
real function resonanceMass(ID, charge, media, FourMomentum, position, perturbative)
PURPOSE
Determines the bare (vacuum) mass of a resonance, if its 4-momentum (effective mass) is known.
INPUTS
- integer :: ID ! ID of resonance
- integer :: charge ! charge of resonance
- type(medium) :: media ! Medium at the point of the resonance
- real :: FourMomentum(0:3) ! 4-momentum of resonance in the LRF
- real :: position(1:3) ! position of resonance in calculation frame
RESULT
- resonance mass in GeV
NOTES
This was known as "detmass" in the old code.
resonanceCrossSections/barMes2resonance [ Functions ]
[ Top ] [ resonanceCrossSections ] [ Functions ]
NAME
function barMes2resonance(idMeson_ini, idBaryon_ini, chargeMeson_ini, chargeBaryon_ini, propagated, mediumAtCollision, momentumLRF, masses, mesonMass, baryonMass, position, perturbative, srts) result (sigma)
PURPOSE
Evaluates baryon meson -> Resonance cross sections by summing over the resonances final state. One gets baryon meson -> X by summing over the (baryon meson -> R-> X) channels for all resonances.
See eq. (2.52) in Effenberger Phd.
INPUTS
- integer :: idMeson_ini
- integer :: idBaryon_ini
- integer :: chargeMeson_ini
- integer :: chargeBaryon_ini
- logical :: propagated --- if .true., then onsider only propagated particles in final state, otherwise consider all particles in final state
- type(medium) :: mediumAtCollision ! Medium information
- real, dimension(0:3) :: momentumLRF ! Momentum of resonance in LRF
- real :: mesonMass ! masses of colliding particles.
- real :: baryonMass ! masses of colliding particles.
- real, dimension(1:3) :: position ! Position where resonance is produced
- logical :: perturbative ! flag for the perturbative nature of resonance
- real, optional :: srts ! sqrt(s) of the collision -- needed in RMF mode
RESULT
- real, dimension(Delta:nbar) :: sigma --- Cross section for each intermediate baryon resonance in units of mB. The index denotes the resonance.
- real, dimension(Delta:nbar) :: masses --- Masses of the produced resonances; index denotes the resonance.
resonanceCrossSections/barMes_R_barMes [ Functions ]
[ Top ] [ resonanceCrossSections ] [ Functions ]
NAME
real function barMes_R_barMes(idMes_in, idBar_in, idMes_out, idBar_out, chargeMes_in, chargeBar_in, chargeMes_out, chargeBar_out, background, propagated, MediumAtCollision, momentumLRF, mesonMass_in, baryonMass_in, position, perturbative, srts)
PURPOSE
Evaluates contribution of resonances to baryon meson -> baryon meson according to the Breit-Wigner formula, cf. eq. (2.52) in Effenberger Phd. One gets B m -> B m by summing over the (b M -> R->b M) channels for all resonances.
INPUTS
- integer :: idMes_in --- IDs of particles in initial state.
- integer :: idBar_in --- IDs of particles in initial state.
- integer :: idMes_out --- IDs of particles in final state.
- integer :: idBar_out --- IDs of particles in final state.
- integer :: chargeMes_in --- Charges of particles in initial state
- integer :: chargeBar_in --- Charges of particles in initial state
- integer :: chargeMes_out --- Charges of particles in final state
- integer :: chargeBar_out --- Charges of particles in final state
- logical :: background --- .true. = Compute background cross section : Therefore consider only non-propagated particles in intermediate state; .false. = Full Xsection : Consider all particles in intermediate state
- logical :: propagated --- .true. = Consider only propagated particles in intermediate state; .false. = Consider all particles in intermediate state
Information for In-Medium modifications :
- type(medium) :: mediumAtCollision --- Medium information at the point of collision
- real, dimension(0:3) :: momentumLRF --- Total Momentum in LRF = Momentum of resonance in LRF
- real :: mesonMass_in --- masses of colliding particles
- real :: baryonMass_in --- masses of colliding particles
- real, dimension(1:3) :: position --- Position where resonance is produced
- logical :: perturbative --- flag for the perturbative nature of resonance
- real, optional :: srts --- sqrt(s) of the collision, needed in RMF mode
NOTES
Note that it is not useful to set both background and propagated to .true. : Result=0.
RESULT
- resonance contribution to baryon meson -> baryon meson (in mb)
resonanceCrossSections/sigma_npi_n2pi_resonances [ Subroutines ]
[ Top ] [ resonanceCrossSections ] [ Subroutines ]
NAME
subroutine sigma_npi_n2pi_resonances(srts,charge_iniPion,background,sigmaTotal)
PURPOSE
Evaluates contribution of resonances to proton Pion -> Nucleon Pion Pion in the VACUUUM assumption [Gamma's are not the medium modified ones] One gets pion p -> pi pi N by summing over the (pion p -> R->pion Delta), (pion p -> R-> N rho), (pion p -> R-> N sigma) and (pion p -> R-> pion P11_1440) channels. All resonances but the P_11(1440) decay fully into N pi. Therefore the final states are in the end N Pi Pi states. For the P_11(1440) the ratio of N pi pi final states is given by its decay ratio into N pi.
INPUTS
- logical, intent(in) :: background --- .true. = Compute background cross section : Therefore consider only non-propagated particles in intermediate state; .false. = Full Xsection : Consider all particles in intermediate state
- real, intent(in) :: srts --- sqrt(s) in the process
- integer, intent(in) :: charge_iniPion --- charge of incoming pion
RESULT
- real, intent(out),dimension(-2:2) :: sigmaTotal --- cross sction in mB
Meaning of index in sigmaTotal :