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LwlynSmithFFNC.cxx
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1 //____________________________________________________________________________
2 /*
3  Copyright (c) 2003-2024, The GENIE Collaboration
4  For the full text of the license visit http://copyright.genie-mc.org
5 
6  Costas Andreopoulos <c.andreopoulos \at cern.ch>
7  University of Liverpool
8 */
9 //____________________________________________________________________________
10 
11 #include <TMath.h>
12 
17 
18 using namespace genie;
19 using namespace genie::constants;
20 
21 //____________________________________________________________________________
23 LwlynSmithFF("genie::LwlynSmithFFNC")
24 {
25 
26 }
27 //____________________________________________________________________________
29 LwlynSmithFF("genie::LwlynSmithFFNC", config)
30 {
31 
32 }
33 //____________________________________________________________________________
35 {
36 
37 }
38 //____________________________________________________________________________
39 double LwlynSmithFFNC::F1V(const Interaction * interaction) const
40 {
41  //-- calculate F1V-CC
42  double F1V_CC = LwlynSmithFF::F1V(interaction);
43 
44  //-- calculate F1p (see hep-ph/0107261)
45  fELFF.Calculate(interaction);
46  double t = LwlynSmithFF::tau(interaction);
47  double F1p = fELFF.Gep() - t * fELFF.Gmp();
48 
49  //-- calculate F1V-NC
50  double F1V_NC = 0.5*F1V_CC - 2*fSin28w*F1p;
51  return F1V_NC;
52 }
53 //____________________________________________________________________________
54 double LwlynSmithFFNC::xiF2V(const Interaction * interaction) const
55 {
56  //-- calculate xiF2V_CC
57  double xiF2V_CC = LwlynSmithFF::xiF2V(interaction);
58 
59  //-- calculate F2p (see hep-ph/0107261)
60  fELFF.Calculate(interaction);
61  double F2p = (fELFF.Gmp() - fELFF.Gep()) / fMuP;
62 
63  //-- calculate xiF2-NC
64  double xiF2V_NC = 0.5*xiF2V_CC - 2*fSin28w*(fMuP-1)*F2p;
65  return xiF2V_NC;
66 }
67 //____________________________________________________________________________
68 double LwlynSmithFFNC::FA(const Interaction * interaction) const
69 {
70  //-- calculate FA_CC(q2)
71  double FA_CC = LwlynSmithFF::FA(interaction);
72 
73  //-- calculate & return FA_NC(q2)
74  double FA_NC = 0.5 * FA_CC;
75  return FA_NC;
76 }
77 //____________________________________________________________________________
78 double LwlynSmithFFNC::Fp(const Interaction * interaction) const
79 {
80  //-- get the momentum transfer
81  const Kinematics & kine = interaction->Kine();
82  double q2 = kine.q2();
83 
84  //-- get struck nucleon mass & pion pass
85  const InitialState & init_state = interaction->InitState();
86  double MN = init_state.Tgt().HitNucMass();
87  double MN2 = TMath::Power(MN, 2);
88  double Mpi2 = TMath::Power(kPionMass, 2);
89 
90  //-- calculate FA
91  double fa = this->FA(interaction);
92 
93  //-- calculate and return Fp
94  double Fp_NC = 2*MN2*fa/(Mpi2-q2);
95  return Fp_NC;
96 }
97 //____________________________________________________________________________
ELFormFactors fELFF
Definition: LwlynSmithFF.h:77
virtual double tau(const Interaction *interaction) const
double FA(const Interaction *interaction) const
Compute the form factor FA for the input interaction.
double HitNucMass(void) const
Definition: Target.cxx:233
double F1V(const Interaction *interaction) const
Compute the form factor F1V for the input interaction.
Generated/set kinematical variables for an event.
Definition: Kinematics.h:39
Summary information for an interaction.
Definition: Interaction.h:56
double q2(bool selected=false) const
Definition: Kinematics.cxx:141
double xiF2V(const Interaction *interaction) const
Compute the form factor xi*F2V for the input interaction.
const Kinematics & Kine(void) const
Definition: Interaction.h:71
virtual double xiF2V(const Interaction *interaction) const
Compute the form factor xi*F2V for the input interaction.
void Calculate(const Interaction *interaction)
Calculate the form factors for the input interaction using the attached algorithm.
virtual double FA(const Interaction *interaction) const
Compute the form factor FA for the input interaction.
double Gmp(void) const
Get the computed form factor Gmp.
Definition: ELFormFactors.h:53
double Gep(void) const
Get the computed form factor Gep.
Definition: ELFormFactors.h:50
const InitialState & InitState(void) const
Definition: Interaction.h:69
Abstract Base Class: implements the QELFormFactorsModelI interface but can not be instantiated...
Definition: LwlynSmithFF.h:36
const Target & Tgt(void) const
Definition: InitialState.h:66
double Fp(const Interaction *interaction) const
Compute the form factor Fp for the input interaction.
virtual double F1V(const Interaction *interaction) const
Compute the form factor F1V for the input interaction.
Initial State information.
Definition: InitialState.h:48