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genie::BergerSehgalFMCOHPiPXSec2015 Class Reference

Computes the triple differential cross section for CC & NC coherent pion production according to the Berger-Sehgal model. v(vbar)A->v(vbar)Api0, vA->l-Api+, vbarA->l+Api-. More...

#include <BergerSehgalFMCOHPiPXSec2015.h>

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Public Member Functions

 BergerSehgalFMCOHPiPXSec2015 ()
 
 BergerSehgalFMCOHPiPXSec2015 (string config)
 
virtual ~BergerSehgalFMCOHPiPXSec2015 ()
 
double XSec (const Interaction *i, KinePhaseSpace_t k) const
 Compute the cross section for the input interaction. More...
 
double Integral (const Interaction *i) const
 
bool ValidProcess (const Interaction *i) const
 Can this cross section algorithm handle the input process? More...
 
void Configure (const Registry &config)
 
void Configure (string config)
 
- Public Member Functions inherited from genie::XSecAlgorithmI
virtual ~XSecAlgorithmI ()
 
virtual bool ValidKinematics (const Interaction *i) const
 Is the input kinematical point a physically allowed one? More...
 
- Public Member Functions inherited from genie::Algorithm
virtual ~Algorithm ()
 
virtual void FindConfig (void)
 
virtual const RegistryGetConfig (void) const
 
RegistryGetOwnedConfig (void)
 
virtual const AlgIdId (void) const
 Get algorithm ID. More...
 
virtual AlgStatus_t GetStatus (void) const
 Get algorithm status. More...
 
virtual bool AllowReconfig (void) const
 
virtual AlgCmp_t Compare (const Algorithm *alg) const
 Compare with input algorithm. More...
 
virtual void SetId (const AlgId &id)
 Set algorithm ID. More...
 
virtual void SetId (string name, string config)
 
const AlgorithmSubAlg (const RgKey &registry_key) const
 
void AdoptConfig (void)
 
void AdoptSubstructure (void)
 
virtual void Print (ostream &stream) const
 Print algorithm info. More...
 

Private Member Functions

void LoadConfig (void)
 
double ExactKinematicTerm (const Interaction *i) const
 
double PionCOMAbsMomentum (const Interaction *i) const
 

Private Attributes

double fMa
 axial mass More...
 
double fRo
 nuclear size scale parameter More...
 
double fCos8c2
 cos^2(Cabibbo angle) More...
 
bool fRSPionXSec
 Use Rein-Sehgal "style" pion-nucleon xsecs. More...
 
const XSecIntegratorIfXSecIntegrator
 

Additional Inherited Members

- Static Public Member Functions inherited from genie::Algorithm
static string BuildParamVectKey (const std::string &comm_name, unsigned int i)
 
static string BuildParamVectSizeKey (const std::string &comm_name)
 
static string BuildParamMatKey (const std::string &comm_name, unsigned int i, unsigned int j)
 
static string BuildParamMatRowSizeKey (const std::string &comm_name)
 
static string BuildParamMatColSizeKey (const std::string &comm_name)
 
- Protected Member Functions inherited from genie::XSecAlgorithmI
 XSecAlgorithmI ()
 
 XSecAlgorithmI (string name)
 
 XSecAlgorithmI (string name, string config)
 
- Protected Member Functions inherited from genie::Algorithm
 Algorithm ()
 
 Algorithm (string name)
 
 Algorithm (string name, string config)
 
void Initialize (void)
 
void DeleteConfig (void)
 
void DeleteSubstructure (void)
 
RegistryExtractLocalConfig (const Registry &in) const
 
RegistryExtractLowerConfig (const Registry &in, const string &alg_key) const
 Split an incoming configuration Registry into a block valid for the sub-algo identified by alg_key. More...
 
template<class T >
bool GetParam (const RgKey &name, T &p, bool is_top_call=true) const
 
template<class T >
bool GetParamDef (const RgKey &name, T &p, const T &def) const
 
template<class T >
int GetParamVect (const std::string &comm_name, std::vector< T > &v, bool is_top_call=true) const
 Handle to load vectors of parameters. More...
 
int GetParamVectKeys (const std::string &comm_name, std::vector< RgKey > &k, bool is_top_call=true) const
 
template<class T >
int GetParamMat (const std::string &comm_name, TMatrixT< T > &mat, bool is_top_call=true) const
 Handle to load matrix of parameters. More...
 
template<class T >
int GetParamMatSym (const std::string &comm_name, TMatrixTSym< T > &mat, bool is_top_call=true) const
 
int GetParamMatKeys (const std::string &comm_name, std::vector< RgKey > &k, bool is_top_call=true) const
 
int AddTopRegistry (Registry *rp, bool owns=true)
 add registry with top priority, also update ownership More...
 
int AddLowRegistry (Registry *rp, bool owns=true)
 add registry with lowest priority, also update ownership More...
 
int MergeTopRegistry (const Registry &r)
 
int AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
 Add registries with top priority, also udated Ownerships. More...
 
- Protected Attributes inherited from genie::Algorithm
bool fAllowReconfig
 
bool fOwnsSubstruc
 true if it owns its substructure (sub-algs,...) More...
 
AlgId fID
 algorithm name and configuration set More...
 
vector< Registry * > fConfVect
 
vector< bool > fOwnerships
 ownership for every registry in fConfVect More...
 
AlgStatus_t fStatus
 algorithm execution status More...
 
AlgMapfOwnedSubAlgMp
 local pool for owned sub-algs (taken out of the factory pool) More...
 

Detailed Description

Computes the triple differential cross section for CC & NC coherent pion production according to the Berger-Sehgal model. v(vbar)A->v(vbar)Api0, vA->l-Api+, vbarA->l+Api-.

     Is a concrete implementation of the XSecAlgorithmI interface.
References:
PRD 79, 053003 (2009) by Berger and Sehgal
Author
G. Perdue, H. Gallagher, D. Cherdack
Created:
2014
License:
Copyright (c) 2003-2024, The GENIE Collaboration For the full text of the license visit http://copyright.genie-mc.org

Definition at line 33 of file BergerSehgalFMCOHPiPXSec2015.h.

Constructor & Destructor Documentation

BergerSehgalFMCOHPiPXSec2015::BergerSehgalFMCOHPiPXSec2015 ( )

Definition at line 30 of file BergerSehgalFMCOHPiPXSec2015.cxx.

30  :
31  XSecAlgorithmI("genie::BergerSehgalFMCOHPiPXSec2015")
32 {
33 
34 }
BergerSehgalFMCOHPiPXSec2015::BergerSehgalFMCOHPiPXSec2015 ( string  config)

Definition at line 36 of file BergerSehgalFMCOHPiPXSec2015.cxx.

36  :
37  XSecAlgorithmI("genie::BergerSehgalFMCOHPiPXSec2015", config)
38 {
39 
40 }
BergerSehgalFMCOHPiPXSec2015::~BergerSehgalFMCOHPiPXSec2015 ( )
virtual

Definition at line 42 of file BergerSehgalFMCOHPiPXSec2015.cxx.

43 {
44 
45 }

Member Function Documentation

void BergerSehgalFMCOHPiPXSec2015::Configure ( const Registry config)
virtual

Configure the algorithm with an external registry The registry is merged with the top level registry if it is owned, Otherwise a copy of it is added with the highest priority

Reimplemented from genie::Algorithm.

Definition at line 284 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::Algorithm::Configure(), and LoadConfig().

285 {
286  Algorithm::Configure(config);
287  this->LoadConfig();
288 }
virtual void Configure(const Registry &config)
Definition: Algorithm.cxx:62
void BergerSehgalFMCOHPiPXSec2015::Configure ( string  config)
virtual

Configure the algorithm from the AlgoConfigPool based on param_set string given in input An algorithm contains a vector of registries coming from different xml configuration files, which are loaded according a very precise prioriy This methods will load a number registries in order of priority: 1) "Tunable" parameter set from CommonParametes. This is loaded with the highest prioriry and it is designed to be used for tuning procedure Usage not expected from the user. 2) For every string defined in "CommonParame" the corresponding parameter set will be loaded from CommonParameter.xml 3) parameter set specified by the config string and defined in the xml file of the algorithm 4) if config is not "Default" also the Default parameter set from the same xml file will be loaded Effectively this avoids the repetion of a parameter when it is not changed in the requested configuration

Reimplemented from genie::Algorithm.

Definition at line 290 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::Algorithm::Configure(), and LoadConfig().

291 {
292  Algorithm::Configure(config);
293  this->LoadConfig();
294 }
virtual void Configure(const Registry &config)
Definition: Algorithm.cxx:62
double BergerSehgalFMCOHPiPXSec2015::ExactKinematicTerm ( const Interaction i) const
private

Definition at line 214 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::ProcessInfo::IsWeakCC(), genie::constants::kGF2, genie::constants::kPi0Mass, genie::constants::kPi2, genie::constants::kPionMass, genie::kRfLab, genie::InitialState::ProbeE(), genie::Interaction::ProcInfo(), genie::Kinematics::Q2(), genie::utils::kinematics::Q2(), and genie::Kinematics::y().

Referenced by XSec().

216 {
217  // This function is a bit inefficient but is being encapsulated as
218  // such in order to possibly migrate into a general kinematics check.
219  const Kinematics & kinematics = interaction -> Kine();
220  const InitialState & init_state = interaction -> InitState();
221 
222  bool pionIsCharged = interaction->ProcInfo().IsWeakCC();
223  double M_pi = pionIsCharged ? kPionMass : kPi0Mass;
224  double E = init_state.ProbeE(kRfLab); // nu E
225  double Q2 = kinematics.Q2();
226  double y = kinematics.y(); // inelasticity
227  double fp2 = (0.93 * M_pi)*(0.93 * M_pi);
228 
229  double term = ((kGF2 * fp2) / (4.0 * kPi2)) *
230  ((E * (1.0 - y)) / sqrt(y*E * y*E + Q2)) *
231  (1.0 - Q2 / (4.0 * E*E * (1.0 - y)));
232  return term;
233 }
double Q2(const Interaction *const i)
Definition: KineUtils.cxx:1077
Generated/set kinematical variables for an event.
Definition: Kinematics.h:39
double y(bool selected=false) const
Definition: Kinematics.cxx:112
double Q2(bool selected=false) const
Definition: Kinematics.cxx:125
double ProbeE(RefFrame_t rf) const
Initial State information.
Definition: InitialState.h:48
double BergerSehgalFMCOHPiPXSec2015::Integral ( const Interaction i) const
virtual

Integrate the model over the kinematic phase space available to the input interaction (kinematical cuts can be included)

Implements genie::XSecAlgorithmI.

Definition at line 259 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References fXSecIntegrator, and genie::XSecIntegratorI::Integrate().

260 {
261  double xsec = fXSecIntegrator->Integrate(this,interaction);
262  return xsec;
263 }
virtual double Integrate(const XSecAlgorithmI *model, const Interaction *interaction) const =0
void BergerSehgalFMCOHPiPXSec2015::LoadConfig ( void  )
private

Definition at line 296 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References fCos8c2, fMa, fRo, fRSPionXSec, fXSecIntegrator, genie::Algorithm::GetParam(), and genie::Algorithm::SubAlg().

Referenced by Configure().

297 {
298  GetParam( "COH-Ma",fMa ) ;
299  GetParam( "COH-Ro", fRo ) ;
300 
301  double thc ;
302  GetParam( "CabibboAngle", thc ) ;
303  fCos8c2 = TMath::Power(TMath::Cos(thc), 2);
304 
305  // fRSPionXSec => Do not use the pion-nucleus cross section from Table 1 in PRD 79, 053003
306  // Instead, use the Rein-Sehgal "style" pion-nucleon cross section and scale by A
307  // for all pion energies.
308  GetParam( "COH-UseRSPionXSec", fRSPionXSec ) ;
309 
310  //-- load the differential cross section integrator
312  dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
313  assert(fXSecIntegrator);
314 }
Cross Section Integrator Interface.
bool fRSPionXSec
Use Rein-Sehgal &quot;style&quot; pion-nucleon xsecs.
double fRo
nuclear size scale parameter
bool GetParam(const RgKey &name, T &p, bool is_top_call=true) const
const Algorithm * SubAlg(const RgKey &registry_key) const
Definition: Algorithm.cxx:345
double BergerSehgalFMCOHPiPXSec2015::PionCOMAbsMomentum ( const Interaction i) const
private

Definition at line 235 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::ProcessInfo::IsWeakCC(), genie::constants::kPi0Mass, genie::constants::kPionMass, genie::kRfLab, genie::Target::Mass(), genie::InitialState::ProbeE(), genie::Interaction::ProcInfo(), genie::Kinematics::Q2(), genie::utils::kinematics::Q2(), genie::InitialState::Tgt(), and genie::Kinematics::y().

Referenced by XSec().

237 {
238  // This function is a bit inefficient but is being encapsulated as
239  // such in order to possibly migrate into a general kinematics check.
240  const Kinematics & kinematics = interaction -> Kine();
241  const InitialState & init_state = interaction -> InitState();
242 
243  bool pionIsCharged = interaction->ProcInfo().IsWeakCC();
244  double M_pi = pionIsCharged ? kPionMass : kPi0Mass;
245  double E = init_state.ProbeE(kRfLab); // nu E
246  double Q2 = kinematics.Q2();
247  double y = kinematics.y(); // inelasticity
248  double MT = init_state.Tgt().Mass();
249 
250  double W2 = MT * MT - Q2 + 2.0 * y * E * MT;
251  double arg = (2.0 * MT * (y * E - M_pi) - Q2 - M_pi * M_pi) *
252  (2.0 * MT * (y * E + M_pi) - Q2 - M_pi * M_pi);
253  if (arg < 0) return arg;
254  double ppistar = TMath::Sqrt(arg) / 2.0 / TMath::Sqrt(W2);
255 
256  return ppistar;
257 }
double Q2(const Interaction *const i)
Definition: KineUtils.cxx:1077
Generated/set kinematical variables for an event.
Definition: Kinematics.h:39
double Mass(void) const
Definition: Target.cxx:224
double y(bool selected=false) const
Definition: Kinematics.cxx:112
double Q2(bool selected=false) const
Definition: Kinematics.cxx:125
const Target & Tgt(void) const
Definition: InitialState.h:66
double ProbeE(RefFrame_t rf) const
Initial State information.
Definition: InitialState.h:48
bool BergerSehgalFMCOHPiPXSec2015::ValidProcess ( const Interaction i) const
virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 265 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::Target::A(), genie::Target::HitNucIsSet(), genie::Interaction::InitState(), genie::pdg::IsAntiNeutrino(), genie::ProcessInfo::IsCoherentProduction(), genie::pdg::IsNeutrino(), genie::ProcessInfo::IsWeak(), genie::kISkipProcessChk, genie::InitialState::ProbePdg(), genie::Interaction::ProcInfo(), and genie::InitialState::Tgt().

Referenced by XSec().

266 {
267  if(interaction->TestBit(kISkipProcessChk)) return true;
268 
269  const InitialState & init_state = interaction->InitState();
270  const ProcessInfo & proc_info = interaction->ProcInfo();
271  const Target & target = init_state.Tgt();
272 
273  int nu = init_state.ProbePdg();
274 
275  if (!proc_info.IsCoherentProduction()) return false;
276  if (!proc_info.IsWeak()) return false;
277  if (target.HitNucIsSet()) return false;
278  if (!(target.A()>1)) return false;
279  if (!pdg::IsNeutrino(nu) && !pdg::IsAntiNeutrino(nu)) return false;
280 
281  return true;
282 }
bool IsWeak(void) const
bool IsNeutrino(int pdgc)
Definition: PDGUtils.cxx:110
int A(void) const
Definition: Target.h:70
bool IsCoherentProduction(void) const
A class encapsulating an enumeration of interaction types (EM, Weak-CC, Weak-NC) and scattering types...
Definition: ProcessInfo.h:46
bool IsAntiNeutrino(int pdgc)
Definition: PDGUtils.cxx:118
A Neutrino Interaction Target. Is a transparent encapsulation of quite different physical systems suc...
Definition: Target.h:40
int ProbePdg(void) const
Definition: InitialState.h:64
bool HitNucIsSet(void) const
Definition: Target.cxx:283
const Target & Tgt(void) const
Definition: InitialState.h:66
const UInt_t kISkipProcessChk
if set, skip process validity checks
Definition: Interaction.h:47
Initial State information.
Definition: InitialState.h:48
double BergerSehgalFMCOHPiPXSec2015::XSec ( const Interaction i,
KinePhaseSpace_t  k 
) const
virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 47 of file BergerSehgalFMCOHPiPXSec2015.cxx.

References genie::Target::A(), genie::units::A, genie::units::b, ExactKinematicTerm(), fCos8c2, genie::units::fermi, fMa, fRo, fRSPionXSec, genie::Interaction::FSPrimLepton(), genie::utils::hadxs::berger::InelasticPionNucleonXSec(), genie::ProcessInfo::IsWeakCC(), genie::constants::kPi, genie::constants::kPi0Mass, genie::constants::kPionMass, genie::constants::kPionMass2, genie::kRfLab, LOG, genie::Target::Mass(), genie::units::mb, pDEBUG, pINFO, PionCOMAbsMomentum(), genie::utils::hadxs::berger::PionNucleusXSec(), genie::InitialState::ProbeE(), genie::Interaction::ProcInfo(), pWARN, genie::Kinematics::Q2(), genie::utils::kinematics::Q2(), genie::Kinematics::t(), genie::InitialState::Tgt(), genie::utils::hadxs::berger::TotalPionNucleonXSec(), genie::XSecAlgorithmI::ValidKinematics(), ValidProcess(), and genie::Kinematics::y().

49 {
50  // Here we are following PRD 79, 053003 (2009) by Berger and Sehgal
51  // This method computes the differential cross section represented
52  // in Eq.'s 6 (CC) and 7 (NC) from that paper.
53 
54  // We have additionally modified the formulae to account for a
55  // non-infinite mass for the target nucleus
56 
57  if(! this -> ValidProcess (interaction) ) return 0.;
58  if(! this -> ValidKinematics (interaction) ) return 0.;
59 
60  const Kinematics & kinematics = interaction -> Kine();
61  const InitialState & init_state = interaction -> InitState();
62 
63  bool pionIsCharged = interaction->ProcInfo().IsWeakCC();
64  double xsec = 0.0;
65 
66  double E = init_state.ProbeE(kRfLab); // nu E
67  double Q2 = kinematics.Q2();
68  double y = kinematics.y(); // inelasticity
69  double t = kinematics.t(); // fun exists?
70  assert(E > 0.);
71  assert(y > 0.);
72  assert(y < 1.);
73  double ppistar = PionCOMAbsMomentum(interaction); // |Center of Mass Momentum|
74  if (ppistar <= 0.0) {
75  LOG("BergerSehgalFMCohPi", pDEBUG) <<
76  "Pion COM momentum negative for Q2 = " << Q2 <<
77  " y = " << y;
78  return 0.0;
79  }
80  double front = ExactKinematicTerm(interaction);
81  if (front <= 0.0) {
82  LOG("BergerSehgalFMCohPi", pDEBUG) << "Exact kin. form = " << front <<
83  " E = " << E << " Q2 = " << Q2 << " y = " << y;
84  return 0.0;
85  }
86 
87  double A = (double) init_state.Tgt().A(); // mass number
88  double A2 = TMath::Power(A, 2.);
89  double A_3 = TMath::Power(A, 1./3.);
90  double M = init_state.Tgt().Mass();
91  double M_pi = pionIsCharged ? kPionMass : kPi0Mass;
92  double M_pi2 = M_pi * M_pi;
93  double Epi = y * E - t / (2 * M);
94  double Epi2 = Epi * Epi;
95  double ma2 = fMa * fMa;
96  double Ga = ma2 / (ma2 + Q2);
97  double Ga2 = Ga * Ga;
98  double Ro2 = TMath::Power(fRo * units::fermi, 2.);
99  double ppi2 = Epi2 - M_pi2;
100  double ppi = ppi2 > 0.0 ? sqrt(ppi2) : 0.0;
101  // double fp = 0.93 * kPionMass; // unused // pion decay constant
102 
103  double costheta = (t - Q2 - M_pi * M_pi) / (2 * ( (y *E - Epi) * Epi -
104  ppi * sqrt(TMath::Power(y * E - Epi, 2.) + t) ) );
105 
106  if ((costheta > 1.0) || (costheta < -1.0)) return 0.0;
107 
108  // tot. pi+N xsec
109  double sTot =
110  utils::hadxs::berger::TotalPionNucleonXSec(Epi, pionIsCharged);
111  double sTot2 = sTot * sTot;
112  // inel. pi+N xsec
113  double sInel =
115 
116  // Fabs (F_{abs}) describes the average attenuation of a pion emerging
117  // from a sphere of nuclear matter with radius = R_0 A^{1/3}. it is
118  // Eq. 13 in Berger-Sehgal PRD 79, 053003
119  double Fabs_input = (9.0 * A_3) / (16.0 * kPi * Ro2);
120  double Fabs = TMath::Exp( -1.0 * Fabs_input * sInel);
121 
122  // A_RS for BS version of RS, and/or Tpi>1.0
123  //double RS_factor = (A2 * Fabs) / (16.0 * kPi) * (sTot2);
124  double R = fRo * A_3 * units::fermi; // nuclear radius
125  double R2 = R * R; //
126  double b = 0.33333 * R2; // Eq. 12 in BS
127  double expbt = TMath::Exp( -b * t );
128  double dsigEldt = sTot2 / (16. * kPi); // Eq. 11 in BS
129  double dsigpiNdt = A2 * dsigEldt * expbt * Fabs; // Eq. 10 in BS
130 
131  double tpilow = 0.0;
132  double siglow = 0.0;
133  double tpihigh = 0.0;
134  double sighigh = 0.0;
135  double dsigdt = 0.0;
136  double tpi = 0.0;
137  int xsec_stat = 0;
138 
139  // differential cross section for pion-nucleus in t (ds/dt term from
140  // Eq. 7 in BS. we will initially set the value to a "Rein-Sehgal style"
141  // computation and update to use the Berger-Sehgal pion-nucleus cross
142  // section where appropriate.
143  double edep_dsigpiNdt = dsigpiNdt;
144 
145  // c.o.m.
146  tpi = Epi - M_pi;
147 
148  if (tpi <= 1.0 && fRSPionXSec == false) {
149  // use the Berger-Sehgal pion-nucleus cross section. note we're only
150  // checking on the pion energy and the conditional flag - is it really
151  // reasonable to ever use this value for non-Carbon targets?
152  xsec_stat =
154  tpi, ppistar, t, A,
155  tpilow, siglow,
156  tpihigh, sighigh);
157  if (xsec_stat != 0)
158  LOG("BergerSehgalFMCohPi", pWARN) <<
159  "Unable to retrieve pion-nucleus cross section with A = " <<
160  A << ", t_pi = " << tpi;
161  dsigdt = siglow + (sighigh - siglow) * (tpi - tpilow) / (tpihigh - tpilow);
162  dsigdt = dsigdt / (2.0 * ppistar * ppistar) * units::mb;
163  edep_dsigpiNdt = dsigdt;
164  }
165 
166  // complete calculation of Eq. 7 in BS paper
167  xsec = front * Ga2 * edep_dsigpiNdt;
168 
169  // Correction for finite final state lepton mass.
170  // Lepton mass modification is part of Berger-Sehgal and is not optional.
171  if (pionIsCharged) {
172  double C = 1.;
173  // First, we need to remove the leading G_{A}^2 which is required for NC.
174  xsec /= Ga2;
175  // Next, \cos^2 \theta_{Cabibbo} appears in the CC xsec, but not the NC.
176  xsec *= fCos8c2;
177  double ml = interaction->FSPrimLepton()->Mass();
178  double ml2 = TMath::Power(ml,2);
179  double Q2min = ml2 * y/(1-y);
180  if(Q2 > Q2min) {
181  double C1 = TMath::Power(Ga - 0.5 * Q2min / (Q2 + kPionMass2), 2);
182  double C2 = 0.25 * y * Q2min * (Q2 - Q2min) /
183  TMath::Power(Q2 + kPionMass2, 2);
184  C = C1 + C2;
185  } else {
186  C = 0.;
187  }
188  xsec *= (2. * C); // *2 is for CC vs NC in BS
189  }
190 
191 #ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
192  LOG("BergerSehgalFMCohPi", pDEBUG)
193  << "\n momentum transfer .............. Q2 = " << Q2
194  << "\n mass number .................... A = " << A
195  << "\n pion energy .................... Epi = " << Epi
196  << "\n propagator term ................ propg = " << propg
197  << "\n Re/Im of fwd pion scat. ampl. .. Re/Im = " << fReIm
198  << "\n total pi+N cross section ....... sigT = " << sTot
199  << "\n inelastic pi+N cross section ... sigI = " << sInel
200  << "\n nuclear size scale ............. Ro = " << fRo
201  << "\n pion absorption factor ......... Fabs = " << Fabs
202  << "\n t integration factor ........... tint = " << tint;
203  LOG("BergerSehgalFMCohPi", pINFO)
204  << "d3xsec/dQ2dydt[COHPi] (x= " << x << ", y="
205  << y << ", E=" << E << ") = "<< xsec;
206 #endif
207 
208  //----- The algorithm computes d^3xsec/dQ^2dydt
209  // Check whether Jacobian tranformation is needed...
210 
211  return xsec;
212 }
double Q2(const Interaction *const i)
Definition: KineUtils.cxx:1077
int A(void) const
Definition: Target.h:70
double TotalPionNucleonXSec(double Epion, bool isChargedPion=true)
Definition: HadXSUtils.cxx:90
Generated/set kinematical variables for an event.
Definition: Kinematics.h:39
double Mass(void) const
Definition: Target.cxx:224
double y(bool selected=false) const
Definition: Kinematics.cxx:112
static constexpr double b
Definition: Units.h:78
double ExactKinematicTerm(const Interaction *i) const
virtual bool ValidKinematics(const Interaction *i) const
Is the input kinematical point a physically allowed one?
bool fRSPionXSec
Use Rein-Sehgal &quot;style&quot; pion-nucleon xsecs.
#define LOG(stream, priority)
A macro that returns the requested log4cpp::Category appending a string (using the FILE...
Definition: Messenger.h:96
static constexpr double A
Definition: Units.h:74
static constexpr double mb
Definition: Units.h:79
double PionCOMAbsMomentum(const Interaction *i) const
bool ValidProcess(const Interaction *i) const
Can this cross section algorithm handle the input process?
#define pINFO
Definition: Messenger.h:62
#define pWARN
Definition: Messenger.h:60
double fRo
nuclear size scale parameter
double InelasticPionNucleonXSec(double Epion, bool isChargedPion=true)
Definition: HadXSUtils.cxx:82
static constexpr double fermi
Definition: Units.h:55
double t(bool selected=false) const
Definition: Kinematics.cxx:170
double Q2(bool selected=false) const
Definition: Kinematics.cxx:125
const Target & Tgt(void) const
Definition: InitialState.h:66
double ProbeE(RefFrame_t rf) const
Initial State information.
Definition: InitialState.h:48
#define pDEBUG
Definition: Messenger.h:63
int PionNucleusXSec(double tpi, double ppistar, double t_new, double A, double &tpilow, double &siglow, double &tpihigh, double &sighigh)
Definition: HadXSUtils.cxx:205

Member Data Documentation

double genie::BergerSehgalFMCOHPiPXSec2015::fCos8c2
private

cos^2(Cabibbo angle)

Definition at line 59 of file BergerSehgalFMCOHPiPXSec2015.h.

Referenced by LoadConfig(), and XSec().

double genie::BergerSehgalFMCOHPiPXSec2015::fMa
private

axial mass

Definition at line 57 of file BergerSehgalFMCOHPiPXSec2015.h.

Referenced by LoadConfig(), and XSec().

double genie::BergerSehgalFMCOHPiPXSec2015::fRo
private

nuclear size scale parameter

Definition at line 58 of file BergerSehgalFMCOHPiPXSec2015.h.

Referenced by LoadConfig(), and XSec().

bool genie::BergerSehgalFMCOHPiPXSec2015::fRSPionXSec
private

Use Rein-Sehgal "style" pion-nucleon xsecs.

Definition at line 60 of file BergerSehgalFMCOHPiPXSec2015.h.

Referenced by LoadConfig(), and XSec().

const XSecIntegratorI* genie::BergerSehgalFMCOHPiPXSec2015::fXSecIntegrator
private

Definition at line 62 of file BergerSehgalFMCOHPiPXSec2015.h.

Referenced by Integral(), and LoadConfig().


The documentation for this class was generated from the following files: