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/lepton2p2h [ Modules ]

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NAME

module lepton2p2h

PURPOSE

Do all the internals for 2p2h scattering:

EM:

  • ell N1 N2 --> ell' N1' N2' == gamma* N1 N2 --> N1' N2'
  • ell N1 N2 --> ell' N Delta == gamma* N1 N2 --> N Delta

NC:

  • nu N1 N2 --> nu' N1' N2'
  • nu N1 N2 --> nu' N Delta

CC:

  • nu N1 N2 --> ell- N1' N2' (sum of hadronic charges increases by +1)
  • nu N1 N2 --> ell- N Delta ( -- " -- )

antiEM, antiNC and antiCC are the same as EM, NC, CC.

cases 1 - 3 give parametrizations for 2p2h part of structure function W1 in terms of Q^2, no distinction for neutrinos and antineutrinos

Cases 1 and 2 are those in: Lalakulich Gallmeister Mosel PRC86(2012)014614 Case 3 gives a reasonable description of MiniBooNE dd neutrino data

cases 4 - 5 give parametrization for MEC part of W1 from Christy and Bosted In this case also W3 is related to W1 (acc. Martini and Ericsson)

Case 4 describes double-differential data from MiniBooNE for neutrino and antineutrino scattering. It also describes the dd inclusive Xsection for neutrinos from T2K.

lepton2p2h/lepton2p2h_DoQE [ Subroutines ]

[ Top ] [ lepton2p2h ] [ Subroutines ]

NAME

subroutine lepton2p2h_DoQE(eN,outPart,XS)

PURPOSE

Do all the electron induced 2p2h-QE scattering gamma* N1 N2 -> N1' N2'

INPUTS

OUTPUT

  • type(particle), dimension(:) :: OutPart -- the two produced nucleons
  • real :: XS -- the cross section

lepton2p2h/lepton2p2h_DoDelta [ Subroutines ]

[ Top ] [ lepton2p2h ] [ Subroutines ]

NAME

subroutine lepton2p2h_DoDelta(eN,outPart,XS)

PURPOSE

Do all the electron induced 2p2h-QE scattering gamma* N1 N2 -> N Delta

INPUTS

OUTPUT

  • type(particle), dimension(:) :: OutPart -- the two produced hadrons
  • real :: XS -- the cross section

lepton2p2h/lepton2p2h_SelectN2 [ Subroutines ]

[ Top ] [ lepton2p2h ] [ Subroutines ]

NAME

subroutine lepton2p2h_SelectN2(eN)

PURPOSE

Finds the second nucleon for the 2p2h collision

INPUTS

OUTPUT

NOTES

  • The seond particle is generated analytically, not by selecting a testparticle from the real particle vector.
  • This is at a very basic level. You may add more sophisticated features as eq. two-particle correlatione etc.
  • A threshold check Wfree>(2*mN+1MeV) is performed

lepton2p2h/lepton2p2h_FinalState [ Subroutines ]

[ Top ] [ lepton2p2h ] [ Subroutines ]

NAME

subroutine lepton2p2h_FinalState(eN,outPart,DoQE,flagOK)

PURPOSE

Generate the final state of the electron 2p2h event

lepton2p2h/lepton2p2h_XS [ Functions ]

[ Top ] [ lepton2p2h ] [ Functions ]

NAME

real function lepton2p2h_XS(eN,outPart,DoQE)

PURPOSE

calculate the electron induced 2p2h-QE cross section

INPUTS

  • type(electronNucleon_event) :: eN -- electron-Nucleon event info
  • type(particle),dimension(:) :: OutPart -- the outgoing particles
  • logical :: DoQE -- .true. for NN final state, .false. for N Delta

OUTPUT

  • the function value

NOTES

lepton2p2h_XS/ME_const [ Functions ]

[ Top ] [ lepton2p2h_XS ] [ Functions ]

NAME

real function ME_const(eN)

PURPOSE

lepton2p2h_XS/ME_transverse [ Functions ]

[ Top ] [ lepton2p2h_XS ] [ Functions ]

NAME

real function ME_transverse(eN)

PURPOSE

lepton2p2h_XS/ME_Dipole_transverse [ Functions ]

[ Top ] [ lepton2p2h_XS ] [ Functions ]

NAME

real function ME_Dipole_transverse(eN)

PURPOSE

calculate the 2p2h matrix element according to W_1(g_munu -q_um q_nu /Q2) * L^munu so that the contribution is only to the transverse part

NOTES

You have full access to all incoming and outgoing particles:

  • eN%lepton_in -- incoming lepton
  • eN%nucleon -- incoming nucleon 1
  • eN%nucleon2 -- incoming nucleon 2

exchanged boson:

  • eN%boson -- exchanged boson

even without considering the final state particles, you know the kind of process via 'eN%idProcess', which may take the values EM,NC,CC and also antiEM,antiNC,antiCC

lepton2p2h_XS/ME_W1W2W3 [ Functions ]

[ Top ] [ lepton2p2h_XS ] [ Functions ]

NAME

real function ME_W1W2W3(eN)

PURPOSE

to calculate the 2p2h contribution to the inclusive cross sections for electrons and neutrinos, cross section depends on all 3 structure functs

NOTES

You have full access to all incoming and outgoing particles:

  • eN%lepton_in -- incoming lepton
  • eN%nucleon -- incoming nucleon 1
  • eN%nucleon2 -- incoming nucleon 2

exchanged boson:

  • eN%boson -- exchanged boson

even without considering the final state particles, you know the kind of process via 'eN%idProcess', which may take the values EM,NC,CC and also antiEM,antiNC,antiCC

ME_W1W2W3/W1 [ Functions ]

[ Top ] [ ME_W1W2W3 ] [ Functions ]

NAME

real function W1(Q2,omega,GM2,GA2)

PURPOSE

Structure function W1 (for electrons: W1E, for neutrinos: W1NU)

W1/W1E [ Functions ]

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NAME

real function W1E(Q2,omega)

PURPOSE

Structure function for electrons, parametrizations for MEC term only

W1E/FAdep_2p2h [ Functions ]

[ Top ] [ W1E ] [ Functions ]

NAME

real function FAdep_2p2h(Atarget)

PURPOSE

W1/Transverse_resp [ Subroutines ]

[ Top ] [ W1 ] [ Subroutines ]

NAME

subroutine Transverse_resp(Q2,omega,GM2,RT,kinfact)

PURPOSE

transverse response = reduced structure function

NOTES

cf. ME_ODW

W1/W1NU [ Functions ]

[ Top ] [ W1 ] [ Functions ]

NAME

real function W1NU(Q2,omega,GMV2,GA2)

PURPOSE

structure function W1 for neutrino-induced CC and NC MEC process

ME_W1W2W3/W2 [ Functions ]

[ Top ] [ ME_W1W2W3 ] [ Functions ]

NAME

real function W2(Q2,omega,GMV2,GA2)

PURPOSE

Structure function W2

ME_W1W2W3/W3 [ Functions ]

[ Top ] [ ME_W1W2W3 ] [ Functions ]

NAME

real function W3(Q2,omega,GMV,GA)

PURPOSE

Structure function W3, relevant only for neutrinos W3 is directly related to W1, either according to Martini and Ericsson, or to O'Connell, Donnelly, Walecka