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/matrixElementQE [ Modules ]

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NAME

module matrixElementQE

PURPOSE

calculates the spin summed and averaged matrix element for EM, CC and NC QE scattering: l + N -> l' + N' Details are given below.


matrixElementQE/useQEextraterm [ Global module-variables ]

[ Top ] [ matrixElementQE ] [ Global module-variables ]

SOURCE

  logical, save :: useQEextraterm=.true.

PURPOSE

switch on/off an extra term appearing in the current due to different masses of in- and outgoing nucleons


matrixElementQE/useCorrelations [ Global module-variables ]

[ Top ] [ matrixElementQE ] [ Global module-variables ]

SOURCE

  logical, save :: useCorrelations=.false.

PURPOSE

switch on/off RPA correlations according to Nieves, Amaro, Valverde, PRC70, 055503 (2004)


matrixElementQE/nievesCorr_para [ Global module-variables ]

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SOURCE

  integer, save :: nievesCorr_para=2

PURPOSE

if RPA correlations are switched on, this parameter decides which set of varibles to use:

  • 1: modified Nieves et al., PRC70, 055503 (2004)
  • 2: original Nieves et al., PRC70, 055503 (2004)
  • 3: Tselyaev, Speth et al., PRC75, 014315 (2007)


matrixElementQE/gp [ Global module-variables ]

[ Top ] [ matrixElementQE ] [ Global module-variables ]

SOURCE

  real, save :: gp=0.63

PURPOSE

vary gp if RPA correlations are switched on


matrixElementQE/withScalarInt [ Global module-variables ]

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SOURCE

  logical, save :: withScalarInt=.true.

PURPOSE

switch on/off scalar interactions


matrixElementQE/readInput_MatrixElementQE [ Subroutines ]

[ Top ] [ matrixElementQE ] [ Subroutines ]

NAME

subroutine readInput_MatrixElementQE

PURPOSE

This subroutine reads namelist 'MatrixElementQE'.


matrixElementQE/MatrixElementQE [ Namelists ]

[ Top ] [ matrixElementQE ] [ Namelists ]

NAME

NAMELIST /MatrixElementQE/

PURPOSE

This Namelist includes:


matrixElementQE/MatrixElementforQE [ Functions ]

[ Top ] [ matrixElementQE ] [ Functions ]

NAME

real function MatrixElementforQE(process_ID,charge_in,k_in,k_out,p_in,p_out,position)

PURPOSE

This function returns the spin summed and averaged matrix element for CC, NC, EM induced quasielastic scattering.

The notation is as follows:

  • MatrixElementforQE=coupling * L_munu H^munu with coupling as in line 173
  • L_munu=Tr((kslash + ml)Atilde(kprslash+mlpr)A) [*1/2 for EM spin average] with A_mu=gamma_mu(1-a gamma_5) where a=0 for EM, 1 for NC,CC neutrino, -1 for NC,CC antineutrino
  • H^munu=1/2 Tr(...) same as above with hadronic current instead

note: Peskin notation for spin sums (no 1/2M !!)

more details in Tinas notes!

INPUTS

  • integer :: process_ID -- CC, NC or EM
  • integer :: charge_in -- charge of incoming nucleon
  • real, dimension(0:3) :: p_in -- momentum of incoming nucleon
  • real, dimension(0:3) :: k_in -- momentum of incoming lepton
  • real, dimension(0:3) :: p_out -- momentum of outgoing nucleon
  • real, dimension(0:3) :: k_out -- momentum of outgoing lepton
  • real, dimension(1:3), optional :: position -- position of incoming nucleon


matrixElementQE/correlationsNieves [ Subroutines ]

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NAME

subroutine correlationsNieves(process_ID,charge_in,p_in,k_in,k_out,ml_out,s_in,t_in,position,dLH)

PURPOSE

This subroutines calculates the RPA correlations for CC, NC and EM processes which then have to be added to the "bare" matrix element.

Calculation from Nieves, Amaro and Valverde, PRC 70, 055503 (2004) code basically written by L. Alvarez-Ruso

INPUTS

  • integer :: process_ID -- CC, NC or EM
  • integer :: charge_in -- charge of incoming nucleon
  • real, dimension(0:3) :: p_in -- momentum of incoming nucleon
  • real, dimension(0:3) :: k_in -- momentum of incoming lepton
  • real, dimension(0:3) :: k_out -- momentum of outgoing lepton
  • real, dimension(1:3) :: position -- position of incoming nucleon
  • real :: ml_out -- mass of outgoing lepton
  • real :: s_in -- Mandelstam s
  • real :: t_in -- Mandelstam t

OUTPUT

  • real :: dLH -- correlation part of the matrix element