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genie::StrumiaVissaniIBDPXSec Class Reference

An implementation of the neutrino - (free) nucleon [inverse beta decay] cross section, valid from the threshold energy (1.806MeV) up to hundreds of MeV. Currently cut off at 1/2 nucleon mass. Based on the Strumia/Vissani paper Phys.Lett.B564:42-54,2003. More...

#include <StrumiaVissaniIBDPXSec.h>

Inheritance diagram for genie::StrumiaVissaniIBDPXSec:
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Collaboration diagram for genie::StrumiaVissaniIBDPXSec:
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Public Member Functions

 StrumiaVissaniIBDPXSec ()
 StrumiaVissaniIBDPXSec (string config)
virtual ~StrumiaVissaniIBDPXSec ()
double XSec (const Interaction *i, KinePhaseSpace_t k) const
 Compute the cross section for the input interaction.
double Integral (const Interaction *i) const
bool ValidProcess (const Interaction *i) const
 Can this cross section algorithm handle the input process?
bool ValidKinematics (const Interaction *i) const
 Is the input kinematical point a physically allowed one?
void Configure (const Registry &config)
void Configure (string config)
Public Member Functions inherited from genie::XSecAlgorithmI
virtual ~XSecAlgorithmI ()
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.
virtual AlgStatus_t GetStatus (void) const
 Get algorithm status.
virtual bool AllowReconfig (void) const
virtual AlgCmp_t Compare (const Algorithm *alg) const
 Compare with input algorithm.
virtual void SetId (const AlgId &id)
 Set algorithm ID.
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.

Private Member Functions

void LoadConfig (void)
double dSigDt (const double sMinusU, const double sMinusMnuc, const double t) const
double MtxElm (const double sMinusU, const double t) const
double RadiativeCorr (const double Ee) const
double FinalStateCorr (const double Ee) const

Static Private Member Functions

static double MAterm (const double t, const double t2, const double f124, const double f22, const double g124, const double g224meM2, const double f1cf2R8, const double g1cg2R16me, const double g1cFsumR)
static double MBterm (const double t, const double f1cf2, const double g1cg2, const double g1cFsumR, const double f22)
static double MCterm (const double t, const double f124, const double f22, const double g124)

Private Attributes

double fCosCabibbo2
double fg1of0
double fMa2
double fMv2
double fNucleonMMDiff
double fEpsilon
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.
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.
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.
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
int AddLowRegistry (Registry *rp, bool owns=true)
 add registry with lowest priority, also update ownership
int MergeTopRegistry (const Registry &r)
int AddTopRegisties (const vector< Registry * > &rs, bool owns=false)
 Add registries with top priority, also udated Ownerships.
Protected Attributes inherited from genie::Algorithm
bool fAllowReconfig
bool fOwnsSubstruc
 true if it owns its substructure (sub-algs,...)
AlgId fID
 algorithm name and configuration set
vector< Registry * > fConfVect
vector< bool > fOwnerships
 ownership for every registry in fConfVect
AlgStatus_t fStatus
 algorithm execution status
AlgMapfOwnedSubAlgMp
 local pool for owned sub-algs (taken out of the factory pool)

Detailed Description

An implementation of the neutrino - (free) nucleon [inverse beta decay] cross section, valid from the threshold energy (1.806MeV) up to hundreds of MeV. Currently cut off at 1/2 nucleon mass. Based on the Strumia/Vissani paper Phys.Lett.B564:42-54,2003.

References:\n Strumia A., Vissani F., Phys. Lett. B564, pp42-54 (2003)
Author
Corey Reed <cjreed \at nikhef.nl> Nikhef
Created:\n June 22, 2009
License:\n Copyright (c) 2003-2025, The GENIE Collaboration
For the full text of the license visit http://copyright.genie-mc.org

Definition at line 32 of file StrumiaVissaniIBDPXSec.h.

Constructor & Destructor Documentation

◆ StrumiaVissaniIBDPXSec() [1/2]

genie::StrumiaVissaniIBDPXSec::StrumiaVissaniIBDPXSec ( )

◆ StrumiaVissaniIBDPXSec() [2/2]

StrumiaVissaniIBDPXSec::StrumiaVissaniIBDPXSec ( string config)

Definition at line 34 of file StrumiaVissaniIBDPXSec.cxx.

34 :
35 XSecAlgorithmI("genie::StrumiaVissaniIBDPXSec", config),
37{
38
39}
const XSecIntegratorI * fXSecIntegrator

References fXSecIntegrator, and genie::XSecAlgorithmI::XSecAlgorithmI().

◆ ~StrumiaVissaniIBDPXSec()

StrumiaVissaniIBDPXSec::~StrumiaVissaniIBDPXSec ( )
virtual

Definition at line 41 of file StrumiaVissaniIBDPXSec.cxx.

42{
43
44}

Member Function Documentation

◆ Configure() [1/2]

void StrumiaVissaniIBDPXSec::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 158 of file StrumiaVissaniIBDPXSec.cxx.

159{
160 Algorithm::Configure(config);
161 this->LoadConfig();
162}
virtual void Configure(const Registry &config)
Definition Algorithm.cxx:62

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

◆ Configure() [2/2]

void StrumiaVissaniIBDPXSec::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 164 of file StrumiaVissaniIBDPXSec.cxx.

165{
166 Algorithm::Configure(config);
167 this->LoadConfig();
168}

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

◆ dSigDt()

double StrumiaVissaniIBDPXSec::dSigDt ( const double sMinusU,
const double sMinusMnuc,
const double t ) const
private

Definition at line 214 of file StrumiaVissaniIBDPXSec.cxx.

217{
218 // return the differential cross section dS/dt. eqn 3 from reference
219 // t = q^2
220 //
221 // for anue + p -> e+ + n , sMinusU = s - u and sMinusMnuc = s - m_p^2
222 // for nue + n -> e- + p , sMinusU = u - s and sMinusMnuc = s - m_n^2
223 // where s = (p_nu + p_p)^2 and u = (p_nu - p_n)^2
224
225 const double numer = kGF2 * fCosCabibbo2;
226 const double denom = (2.000 * kPi) * sMinusMnuc*sMinusMnuc;
227 assert(TMath::Abs(denom) > fEpsilon); // avoid divide by zero
228
229 return ( (numer / denom) * MtxElm(sMinusU, t) );
230}
double MtxElm(const double sMinusU, const double t) const

References fCosCabibbo2, fEpsilon, genie::constants::kGF2, genie::constants::kPi, and MtxElm().

Referenced by XSec().

◆ FinalStateCorr()

double StrumiaVissaniIBDPXSec::FinalStateCorr ( const double Ee) const
private

Definition at line 379 of file StrumiaVissaniIBDPXSec.cxx.

380{
381 // Sommerfeld factor; correction for final state interactions.
382 // eqn 15 of the reference
383
384 assert(Ee > fEpsilon); // must be non-zero and positive
385 const double eta = 2.000*kPi*kAem
386 / TMath::Sqrt(1.000 - (kElectronMass2 / (Ee*Ee)));
387 const double expn = TMath::Exp(-1.000 * eta);
388 assert(expn < 1.000);
389 return ( eta / (1.000 - expn) );
390}

References fEpsilon, genie::constants::kAem, genie::constants::kElectronMass2, and genie::constants::kPi.

Referenced by XSec().

◆ Integral()

double StrumiaVissaniIBDPXSec::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 110 of file StrumiaVissaniIBDPXSec.cxx.

111{
112 // Compute the total cross section for a free nucleon target
113
114 assert(interaction!=0);
115 if(! this -> ValidProcess (interaction) ) return 0.;
116 if(! this -> ValidKinematics (interaction) ) return 0.;
117
118 assert(fXSecIntegrator!=0);
119 double xsec = fXSecIntegrator->Integrate(this, interaction);
120
121 return xsec;
122}
bool ValidProcess(const Interaction *i) const
Can this cross section algorithm handle the input process?
bool ValidKinematics(const Interaction *i) const
Is the input kinematical point a physically allowed one?

References fXSecIntegrator, ValidKinematics(), and ValidProcess().

◆ LoadConfig()

void StrumiaVissaniIBDPXSec::LoadConfig ( void )
private

Definition at line 170 of file StrumiaVissaniIBDPXSec.cxx.

171{
172
173 // cabibbo angle
174 double cab ;
175 GetParam( "CabibboAngle", cab ) ;
176 const double cosCab = TMath::Cos(cab);
177 fCosCabibbo2 = cosCab*cosCab;
178
179 // form factor params
180 GetParam( "QEL-FA0", fg1of0 ) ;
181 double ma, mv ;
182 GetParam( "QEL-Ma", ma ) ;
183 GetParam( "QEL-Mv", mv ) ;
184 fMa2 = ma*ma;
185 fMv2 = mv*mv;
186
187 // magnetic moments
188
189 double mup, mun ;
190 GetParam( "AnomMagnMoment-P", mup );
191 GetParam( "AnomMagnMoment-N", mun );
192 fNucleonMMDiff = (mup - 1.000) - mun; // *anamolous* mag. mom. diff.
193
194 // numeric
195 int epmag ;
196 GetParam("EpsilonMag", epmag ) ;
197 fEpsilon = TMath::Power(10.000, -1.000 * static_cast<double>(epmag) );
198
199 LOG("StrumiaVissani", pINFO) << "*** USING: cos2(Cabibbo)="
200 << fCosCabibbo2
201 << ", g1(0)=" << fg1of0
202 << ", Ma^2=" << fMa2
203 << ", Mv^2=" << fMv2
204 << ", xi=" << fNucleonMMDiff
205 << ", epsilon=" << fEpsilon;
206
207 // load XSec Integrator
209 dynamic_cast<const XSecIntegratorI *> (this->SubAlg("XSec-Integrator"));
210 assert(fXSecIntegrator!=0);
211
212}
#define pINFO
Definition Messenger.h:62
#define LOG(stream, priority)
A macro that returns the requested log4cpp::Category appending a string (using the FILE,...
Definition Messenger.h:96
bool GetParam(const RgKey &name, T &p, bool is_top_call=true) const
const Algorithm * SubAlg(const RgKey &registry_key) const

References fCosCabibbo2, fEpsilon, fg1of0, fMa2, fMv2, fNucleonMMDiff, fXSecIntegrator, genie::Algorithm::GetParam(), LOG, pINFO, and genie::Algorithm::SubAlg().

Referenced by Configure(), and Configure().

◆ MAterm()

double StrumiaVissaniIBDPXSec::MAterm ( const double t,
const double t2,
const double f124,
const double f22,
const double g124,
const double g224meM2,
const double f1cf2R8,
const double g1cg2R16me,
const double g1cFsumR )
staticprivate

Definition at line 299 of file StrumiaVissaniIBDPXSec.cxx.

308{
309 // return A(t) in the matrix element calculation
310 // from eqn 6 (without the factor 16)
311 //
312 // for speed purposes, no check that |t|^2 = t2 is performed
313
314 // store multiply used terms
315 const double tmme2 = t - kElectronMass2;
316 const double tpme2 = t + kElectronMass2;
317
318 double r1 = f124 * ( k4NucMass2 + tpme2);
319 r1 += g124 * (-k4NucMass2 + tpme2);
320 r1 += f22 * ( (t2/kNucleonMass2) + 4.000*tpme2 );
321 r1 += g224meM2 * t;
322 r1 += f1cf2R8 * (2.000*t + kElectronMass2);
323 r1 += g1cg2R16me;
324 r1 *= tmme2;
325
326 double r2 = (f124 + (t * (f22 / kNucleonMass2))) * (k4NucMass2 + tmme2);
327 r2 += g124 * (k4NucMass2 - tmme2);
328 r2 += g224meM2 * tmme2;
329 r2 += f1cf2R8 * (2.000*t - kElectronMass2);
330 r2 += g1cg2R16me;
331 r2 *= kNucMassDiff2;
332
333 const double r3 = 32.000 * kElectronMass2 * kNucleonMass * kNucMassDiff
334 * g1cFsumR;
335
336 return ( r1 - r2 - r3 );
337}

References genie::constants::k4NucMass2, genie::constants::kElectronMass2, genie::constants::kNucleonMass, genie::constants::kNucleonMass2, genie::constants::kNucMassDiff, and genie::constants::kNucMassDiff2.

Referenced by MtxElm().

◆ MBterm()

double StrumiaVissaniIBDPXSec::MBterm ( const double t,
const double f1cf2,
const double g1cg2,
const double g1cFsumR,
const double f22 )
staticprivate

Definition at line 339 of file StrumiaVissaniIBDPXSec.cxx.

344{
345 // return C(t) in the matrix element calculation
346 // from eqn 6 (without the factor 16)
347
348 double bterm = 16.000 * t * g1cFsumR;
349 bterm += ( k4EleMass2 * kNucMassDiff
350 * (f22 + (f1cf2 + 2.000*g1cg2)) ) / kNucleonMass2;
351 return bterm;
352}

References genie::constants::k4EleMass2, genie::constants::kNucleonMass2, and genie::constants::kNucMassDiff.

Referenced by MtxElm().

◆ MCterm()

double StrumiaVissaniIBDPXSec::MCterm ( const double t,
const double f124,
const double f22,
const double g124 )
staticprivate

Definition at line 354 of file StrumiaVissaniIBDPXSec.cxx.

358{
359 // return C(t) in the matrix element calculation
360 // from eqn 6 (without the factor 16)
361
362 return ( f124 + g124 - (t * ( f22 / kNucleonMass2 )) );
363}

References genie::constants::kNucleonMass2.

Referenced by MtxElm().

◆ MtxElm()

double StrumiaVissaniIBDPXSec::MtxElm ( const double sMinusU,
const double t ) const
private

Definition at line 232 of file StrumiaVissaniIBDPXSec.cxx.

234{
235 // return the square of the matrix element. eqn 5 from the reference paper
236 // |M^2| = A(t) - (s-u)B(t) + (s-u)^2 C(t)
237 //
238 // factor 16 comes from eqn 6
239 //
240 // for anue + p -> e+ + n , sMinusU = s - u
241 // for nue + n -> e- + p , sMinusU = u - s
242 // where s = (p_nu + p_p)^2 and u = (p_nu - p_n)^2
243
244 // store multiply used variables to reduce number of calculations
245 const double t4m = t / k4NucMass2;
246 const double t2 = t * t;
247
248 const double fdenomB = 1.000 - (t / fMv2);
249 const double fdenom = (1.000 - t4m)*fdenomB*fdenomB;
250 const double g1denom = 1.000 - (t / fMa2);
251 const double g2denom = kPionMass2 - t;
252 assert(TMath::Abs(fdenom) > fEpsilon); // avoid divide by zero
253 assert(TMath::Abs(g1denom) > fEpsilon); // avoid divide by zero
254 assert(TMath::Abs(g2denom) > fEpsilon); // avoid divide by zero
255
256 const double f1 = (1.000 - ( (1.000+fNucleonMMDiff) * t4m)) / fdenom;
257 const double f2 = fNucleonMMDiff / fdenom;
258 const double g1 = fg1of0 / (g1denom*g1denom);
259 const double g2 = (2.000 * kNucleonMass2 * g1) / g2denom;
260
261 const double f12 = f1 * f1;
262 const double f124 = 4.000 * f12;
263 const double f22 = f2 * f2;
264 const double g12 = g1 * g1;
265 const double g124 = 4.000 * g12;
266 const double g22 = g2 * g2;
267 const double g224meM2 = 4.000 * g22 * kElectronMass2 / kNucleonMass2;
268
269 const double g1cFsumR = g1 * (f1+f2);
270 const double f1cf2 = f1 * f2;
271 const double g1cg2 = g1 * g2;
272 const double f1cf2R8 = f1cf2 * 8.000;
273 const double g1cg2R16me = g1cg2 * 16.000 * kElectronMass2;
274
275#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
276 LOG("StrumiaVissani", pDEBUG) << "*** t = " << t
277 << ", g2 = " << g2
278 << ", g1 = " << g1
279 << ", f1 = " << f1
280 << ", f2 = " << f2;
281#endif
282
283 // ok - now calculate the terms of the matrix element
284 const double mat = MAterm(t, t2, f124, f22, g124,
285 g224meM2, f1cf2R8, g1cg2R16me, g1cFsumR);
286 const double mbt = MBterm(t, f1cf2, g1cg2, g1cFsumR, f22);
287 const double mct = MCterm(t, f124, f22, g124);
288
289 const double M2 = mat - (sMinusU * (mbt - (sMinusU * mct)));
290#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
291 LOG("StrumiaVissani", pDEBUG) << "*** Matrix element = " << (M2 / 16.000)
292 << " [16A=" << mat << "] [16B=" << mbt
293 << "] [16C=" << mct << "]";
294#endif
295
296 return ( M2 / 16.000 );
297}
#define pDEBUG
Definition Messenger.h:63
static double MAterm(const double t, const double t2, const double f124, const double f22, const double g124, const double g224meM2, const double f1cf2R8, const double g1cg2R16me, const double g1cFsumR)
static double MBterm(const double t, const double f1cf2, const double g1cg2, const double g1cFsumR, const double f22)
static double MCterm(const double t, const double f124, const double f22, const double g124)

References fEpsilon, fg1of0, fMa2, fMv2, fNucleonMMDiff, genie::constants::k4NucMass2, genie::constants::kElectronMass2, genie::constants::kNucleonMass2, genie::constants::kPionMass2, LOG, MAterm(), MBterm(), MCterm(), and pDEBUG.

Referenced by dSigDt().

◆ RadiativeCorr()

double StrumiaVissaniIBDPXSec::RadiativeCorr ( const double Ee) const
private

Definition at line 365 of file StrumiaVissaniIBDPXSec.cxx.

366{
367 // radiative correction to the cross section. eqn 14 from the reference
368 // only valid for Ev<<m_p!
369
370 assert(Ee > fEpsilon); // must be non-zero and positive
371 double rc = 6.000 + (1.500 * TMath::Log(kProtonMass / (2.000*Ee)));
372 rc += 1.200 * TMath::Power((kElectronMass / Ee), 1.500);
373 rc *= kAem / kPi;
374 rc += 1.000;
375 return rc;
376
377}

References fEpsilon, genie::constants::kAem, genie::constants::kElectronMass, genie::constants::kPi, and genie::constants::kProtonMass.

Referenced by XSec().

◆ ValidKinematics()

bool StrumiaVissaniIBDPXSec::ValidKinematics ( const Interaction * i) const
virtual

Is the input kinematical point a physically allowed one?

Reimplemented from genie::XSecAlgorithmI.

Definition at line 140 of file StrumiaVissaniIBDPXSec.cxx.

141{
142 if(interaction->TestBit(kISkipKinematicChk)) return true;
143
144 const InitialState & init_state = interaction -> InitState();
145 const double Ev = init_state.ProbeE(kRfHitNucRest);
146 static const double Ecutoff = kNucleonMass / 2;
147 if (Ev > Ecutoff) {
148 LOG("StrumiaVissani", pERROR) << "*** Ev=" << Ev
149 << " is too large for VLE QEL!";
150 } else if (init_state.IsNuBarP() || init_state.IsNuN()) {
151 const KPhaseSpace & kps = interaction->PhaseSpace();
152 return kps.IsAboveThreshold();
153 }
154
155 return false;
156}
#define pERROR
Definition Messenger.h:59
bool IsNuN(void) const
is neutrino + neutron?
double ProbeE(RefFrame_t rf) const
bool IsNuBarP(void) const
is anti-neutrino + proton?
bool IsAboveThreshold(void) const
Checks whether the interaction is above the energy threshold.
const UInt_t kISkipKinematicChk
if set, skip kinematic validity checks
Definition Interaction.h:48
@ kRfHitNucRest
Definition RefFrame.h:30

References genie::KPhaseSpace::IsAboveThreshold(), genie::InitialState::IsNuBarP(), genie::InitialState::IsNuN(), genie::kISkipKinematicChk, genie::constants::kNucleonMass, genie::kRfHitNucRest, LOG, pERROR, genie::Interaction::PhaseSpace(), and genie::InitialState::ProbeE().

Referenced by Integral(), and XSec().

◆ ValidProcess()

bool StrumiaVissaniIBDPXSec::ValidProcess ( const Interaction * i) const
virtual

Can this cross section algorithm handle the input process?

Implements genie::XSecAlgorithmI.

Definition at line 124 of file StrumiaVissaniIBDPXSec.cxx.

125{
126 if(interaction->TestBit(kISkipProcessChk)) return true;
127
128 // should be IBD and either nu_e + n or anu_e + p
129 if (interaction->ProcInfo().IsInverseBetaDecay()) {
130
131 const InitialState & init_state = interaction -> InitState();
132 const Target & target = init_state.Tgt();
133 if ( (target.IsProton() && pdg::IsAntiNuE(init_state.ProbePdg())) || (target.IsNeutron() && pdg::IsNuE(init_state.ProbePdg()) ))
134 return true;
135 }
136 LOG("StrumiaVissani", pERROR) << "*** Should be IBD processes either nu_e + n or anu_e + p!";
137 return false;
138}
const Target & Tgt(void) const
int ProbePdg(void) const
bool IsNeutron(void) const
Definition Target.cxx:267
bool IsProton(void) const
Definition Target.cxx:262
bool IsNuE(int pdgc)
Definition PDGUtils.cxx:158
bool IsAntiNuE(int pdgc)
Definition PDGUtils.cxx:173
const UInt_t kISkipProcessChk
if set, skip process validity checks
Definition Interaction.h:47

References genie::pdg::IsAntiNuE(), genie::ProcessInfo::IsInverseBetaDecay(), genie::Target::IsNeutron(), genie::pdg::IsNuE(), genie::Target::IsProton(), genie::kISkipProcessChk, LOG, pERROR, genie::InitialState::ProbePdg(), genie::Interaction::ProcInfo(), and genie::InitialState::Tgt().

Referenced by Integral(), and XSec().

◆ XSec()

double StrumiaVissaniIBDPXSec::XSec ( const Interaction * i,
KinePhaseSpace_t k ) const
virtual

Compute the cross section for the input interaction.

Implements genie::XSecAlgorithmI.

Definition at line 46 of file StrumiaVissaniIBDPXSec.cxx.

48{
49 // compute the differential cross section ds/dt
50
51 if(! this -> ValidProcess (interaction) ) return 0.;
52 if(! this -> ValidKinematics (interaction) ) return 0.;
53
54 const InitialState & init_state = interaction -> InitState();
55 const double Ev = init_state.ProbeE(kRfHitNucRest);
56 const Target & target = init_state.Tgt();
57 const bool isProt = target.IsProton();
58 const Kinematics & kine = interaction->Kine();
59 const double q2 = kine.q2();
60 const double mp = (isProt) ? kProtonMass : kNeutronMass;
61 const double mp2 = (isProt) ? kProtonMass2 : kNeutronMass2;
62 const double mn2 = (isProt) ? kNeutronMass2 : kProtonMass2;
63
64 // calculate s-u and s-m_nucleon^2 in nucleon rest frame
65 // need E_e
66 const double Ee = Ev + ( (q2 - mn2 + mp2) / (2.000*mp) );
67 const double sMinusU = ((2.000*mp*(Ev+Ee)) - kElectronMass2)
68 * (isProt ? 1.000 : -1.000);
69 const double sMinusMp2 = 2.000*mp*Ev;
70
71#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
72 LOG("StrumiaVissani", pDEBUG) << "*** Ev = " << Ev
73 << ", q2 = " << q2
74 << ", Ee = " << Ee
75 << ", s-u = " << sMinusU
76 << ", s-Mp2 = " << sMinusMp2;
77#endif
78
79 double xsec = dSigDt(sMinusU, sMinusMp2, q2);
80#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
81 LOG("StrumiaVissani", pDEBUG) << "*** dSdt = " << xsec;
82#endif
83
84 // apply correction factors
85 const double rdcf = RadiativeCorr(Ee);
86 const double fscf = (isProt) ? 1.00 : FinalStateCorr(Ee);
87 xsec *= rdcf * fscf;
88#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
89 LOG("StrumiaVissani", pDEBUG) << "*** rad.corr. = " << rdcf
90 << ", fin.st.cor. = " << fscf
91 << ", xsec = " << xsec;
92#endif
93
94 //----- The algorithm computes dxsec/dt, t=q^2
95 // Check whether variable tranformation is needed
96 if(kps!=kPSq2fE && kps!=kPSQ2fE) {
97 const double J = utils::kinematics::Jacobian(interaction,kPSq2fE,kps);
98 xsec *= J;
99#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
100 LOG("StrumiaVissani", pDEBUG) << "*** Jacobian = " << J;
101#endif
102 }
103
104#ifdef __GENIE_LOW_LEVEL_MESG_ENABLED__
105 LOG("StrumiaVissani", pDEBUG) << "*** xsec = " << xsec;
106#endif
107 return xsec;
108}
double q2(bool selected=false) const
double dSigDt(const double sMinusU, const double sMinusMnuc, const double t) const
double RadiativeCorr(const double Ee) const
double FinalStateCorr(const double Ee) const
double Jacobian(const Interaction *const i, KinePhaseSpace_t f, KinePhaseSpace_t t)
double J(double q0, double q3, double Enu, double ml)
Definition MECUtils.cxx:147

References dSigDt(), FinalStateCorr(), genie::Target::IsProton(), genie::utils::kinematics::Jacobian(), genie::constants::kElectronMass2, genie::Interaction::Kine(), genie::constants::kNeutronMass, genie::constants::kNeutronMass2, genie::constants::kProtonMass, genie::constants::kProtonMass2, genie::kPSQ2fE, genie::kPSq2fE, genie::kRfHitNucRest, LOG, pDEBUG, genie::InitialState::ProbeE(), genie::Kinematics::q2(), RadiativeCorr(), genie::InitialState::Tgt(), ValidKinematics(), and ValidProcess().

Member Data Documentation

◆ fCosCabibbo2

double genie::StrumiaVissaniIBDPXSec::fCosCabibbo2
private

Definition at line 81 of file StrumiaVissaniIBDPXSec.h.

Referenced by dSigDt(), and LoadConfig().

◆ fEpsilon

double genie::StrumiaVissaniIBDPXSec::fEpsilon
private

Definition at line 86 of file StrumiaVissaniIBDPXSec.h.

Referenced by dSigDt(), FinalStateCorr(), LoadConfig(), MtxElm(), and RadiativeCorr().

◆ fg1of0

double genie::StrumiaVissaniIBDPXSec::fg1of0
private

Definition at line 82 of file StrumiaVissaniIBDPXSec.h.

Referenced by LoadConfig(), and MtxElm().

◆ fMa2

double genie::StrumiaVissaniIBDPXSec::fMa2
private

Definition at line 83 of file StrumiaVissaniIBDPXSec.h.

Referenced by LoadConfig(), and MtxElm().

◆ fMv2

double genie::StrumiaVissaniIBDPXSec::fMv2
private

Definition at line 84 of file StrumiaVissaniIBDPXSec.h.

Referenced by LoadConfig(), and MtxElm().

◆ fNucleonMMDiff

double genie::StrumiaVissaniIBDPXSec::fNucleonMMDiff
private

Definition at line 85 of file StrumiaVissaniIBDPXSec.h.

Referenced by LoadConfig(), and MtxElm().

◆ fXSecIntegrator

const XSecIntegratorI* genie::StrumiaVissaniIBDPXSec::fXSecIntegrator
private

Definition at line 88 of file StrumiaVissaniIBDPXSec.h.

Referenced by Integral(), LoadConfig(), and StrumiaVissaniIBDPXSec().


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