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/neutrinoXsection [ Modules ]

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NAME

module neutrinoXsection

PURPOSE

This module calculates various neutrino cross sections, depending on the choice of the user:

  • integrated or differential or double differential cross sections (according to the value of nuXsectionmode, the corresponding subroutines are called in the neutrino init file)
  • EM, CC or NC (according to the value of process_ID given as input to the corresponding subroutines)
  • muon, electron or tau flavor (according to the value of flavor_ID given as input to the corresponding subroutines)

neutrinoXsection/debugflag [ Global module-variables ]

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SOURCE

  logical, parameter :: debugflag=.false.

PURPOSE

to switch on/off debug information

neutrinoXsection/nuclear_phasespace [ Global module-variables ]

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SOURCE

  logical, parameter :: nuclear_phasespace=.true.

PURPOSE

to change between different phasespace factors. (change only for debugging purposes):

  • .false. = 1/SP(k_in,p_in) i.e. phasespace factor for each nucleon
  • .true. = 1/k_in(0)*p_in(0) i.e. global phasespace factor for the nucleus

neutrinoXsection/singlePiModel [ Global module-variables ]

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SOURCE

  integer, save :: singlePiModel=1

PURPOSE

to change between different models for the pion nucleon cross section:

  • 0 = pi N according to Nieves et al (hep-ph/0701149)
  • 1 = MAID-like model
  • 2 = Bosted-Christy

neutrinoXsection/invariantMassCut [ Global module-variables ]

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SOURCE

  real, save :: invariantMassCut=100.

PURPOSE

cut events with invariant Mass above this value (in GeV); cut pion production from Delta and DIS on Wrec = Sqrt[M^2 + 2*M*nu - Q^2]

neutrinoXsection/invariantMassCut_BG [ Global module-variables ]

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SOURCE

  real, save :: invariantMassCut_BG=100.

PURPOSE

cut MAID-like background events with invariantMass_BG above this value (in GeV); cut 1pi BG on Wrec = Sqrt[M^2 + 2*M*nu - Q^2]

neutrinoXsection/DIScutW [ Global module-variables ]

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SOURCE

  real, save :: DIScutW = 2.9

PURPOSE

W-cut for sigmoid onset of DIS

neutrinoXsection/DIScutwidth [ Global module-variables ]

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SOURCE

  real, save :: DIScutwidth = 0.05

PURPOSE

width for sigmoid onset of DIS

neutrinoXsection/REScutW [ Global module-variables ]

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SOURCE

  real, save :: REScutW = 2.0

PURPOSE

W-cut for end of 1pi,2pi BGs

neutrinoXsection/Q2cutoff [ Global module-variables ]

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SOURCE

  logical, save :: Q2cutoff = .true.

PURPOSE

cuts low Q^2 for W > 3 GeV

neutrinoXsection/DISformfakEM [ Global module-variables ]

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SOURCE

  integer,save :: DISformfakEM = 2

PURPOSE

Introduce an additional form factor for the DIS cross section, when processed via a photon:

In case of electron induced events, we need choose 2 in order to be compatible with Pythia's electron machinery.

neutrinoXsection/DISformfakNCCC [ Global module-variables ]

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SOURCE

  integer,save :: DISformfakNCCC = 1

PURPOSE

Introduce an additional form factor for the DIS cross section, when processed via W or Z boson:

In case of electron induced events, we need choose 2 in order to be compatible with Pythia's electron machinery.

neutrinoXsection/mcutDIS [ Global module-variables ]

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SOURCE

  real, save :: mcutDIS = 0.34

PURPOSE

parameter to control Q^2 dependence of DIS

neutrinoXsection/DISrespectHad [ Global module-variables ]

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SOURCE

  logical, save :: DISrespectHad = .true.

PURPOSE

Flag to indicate, whether hadronization failures should be respected and affect the overall DIS cross section

Pythia is run to generate the DIS cross section. But not every of the generated events may lead to a correct hadronic final state.

neutrinoXsection/DISdoMSTP23 [ Global module-variables ]

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SOURCE

  logical, save :: DISdoMSTP23 = .true.

PURPOSE

Flag to indicate, whether in Pythia for neutrino-DIS the value MSTP(23)=1 should be used or not

neutrinoXsection/new2piBG [ Global module-variables ]

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SOURCE

  logical, save :: new2piBG = .true.

PURPOSE

Flag to turn on the new treatment of 2pi BG for electrons and neutrinos

neutrinoXsection/indBG [ Global module-variables ]

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SOURCE

  integer, save :: indBG = 3

PURPOSE

Index to choose Bloom-Gilman like BG parametrization 1 : original Bloom Gilman 2 : Niculescu fit 3 : nonresonant BG fit from Christy-Bosted

neutrinoXsection/readinput [ Subroutines ]

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NAME

subroutine readinput

PURPOSE

This subroutine reads input out of jobcard.

neutrinoXsection/nl_neutrinoxsection [ Namelists ]

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NAME

NAMELIST /nl_neutrinoxsection/

PURPOSE

This Namelist includes:

neutrinoXsection/XsecdCosthetadElepton [ Subroutines ]

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NAME

subroutine XsecdCosthetadElepton(eNev,IP,OutPart,sig)

PURPOSE

This subroutine is the basic subroutine, which does all the job of calculating the cross section dSigma/dCost dElepton and generating a corresponding final state particle vector.

This routine is called by all routines called "Xsec_...".

INPUTS

OUTPUT

NOTES

For the outgoing particles OutPart, the following entries have to be set afterwards:

  • OutPart%firstEvent
  • OutPart%event(1:2)
  • OutPart%pert
  • OutPart%vel
  • OutPart%offshellPar
  • OutPart%perweight

All the other values are set in this routine.

Returned cross section is in 10^-38 cm^2/GeV, except for EM, where the units are nb/GeV

neutrinoXsection/SetHadronCharge [ Functions ]

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NAME

logical function SetHadronCharge(eNev,IP,Q_R,Q_pi)

PURPOSE

This function sets the charge of the outgoing hadrons depending on the reaction process. If successful, SetHadronCharge=.true., if not (when the reaction is not possible) SetHadronCharge=.false.

INPUTS

OUTPUT

  • integer :: Q_R -- charge of outgoing baryon
  • integer :: Q_pi -- charge of outgoing pion
  • function value -- indicates possible failures

neutrinoXsection/get_xsection_namelist [ Subroutines ]

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NAME

subroutine get_xsection_namelist(XsectionMode, ...)

PURPOSE

This subroutine returns variables that are set in the according xsection namelist.

INPUTS:

  • integer, optional :: XsectionMode

OUTPUT

  • logical,optional :: Gdebugflag
  • logical,optional :: Gnuclear_phasespace
  • integer,optional :: GsinglePiModel
  • integer,optional :: GintegralPrecision
  • integer,optional :: GintegralPrecisionQE
  • real,optional :: Genu
  • real,optional :: Gdelta_enu
  • real,optional :: GQs
  • real,optional :: Gdelta_Qs
  • real,optional :: Gcostheta,
  • real,optional :: Gdelta_costheta
  • real,optional :: Gelepton
  • real,optional :: Gdelta_elepton
  • real,optional :: GinvariantMasscut