Pythia8::TopRecoilHook Class Reference

Inheritance diagram for Pythia8::TopRecoilHook:

Collaboration diagram for Pythia8::TopRecoilHook:

Public Member Functions
	TopRecoilHook (bool doTopRecoilIn=true, bool useOldDipoleIn=false, bool doListIn=false)
	~TopRecoilHook () override
virtual bool	initAfterBeams () override
virtual bool	canVetoFSREmission () override
virtual bool	doVetoFSREmission (int sizeOld, const Event &event, int iSys, bool inResonance) override

Private Attributes
bool	m_doTopRecoil {}
bool	m_useOldDipole {}
bool	m_doList {}
bool	m_recoilDeadCone {}
Hist *	m_wtCorr {}

Detailed Description

Definition at line 21 of file TopRecoilHook.cxx.

Constructor & Destructor Documentation

TopRecoilHook()

Pythia8::TopRecoilHook::TopRecoilHook ( bool  doTopRecoilIn = true, bool  useOldDipoleIn = false, bool  doListIn = false  )

inline

Definition at line 29 of file TopRecoilHook.cxx.

                                                                                             {
      m_doTopRecoil = doTopRecoilIn;
      m_useOldDipole = useOldDipoleIn;
      m_doList = doListIn; 
      // Constructor also creates some histograms for analysis inside User Hook.
      m_wtCorr = new Hist("corrective weight", 100, 0., 2.);
      std::cout << " enabling TopRecoilHook"<< std::endl;
 
    }

~TopRecoilHook()

Pythia8::TopRecoilHook::~TopRecoilHook ( )

inlineoverride

Definition at line 40 of file TopRecoilHook.cxx.

                              {
      if (m_doTopRecoil) cout << *m_wtCorr;
      delete m_wtCorr;
    }

Member Function Documentation

canVetoFSREmission()

virtual bool Pythia8::TopRecoilHook::canVetoFSREmission ( )

inlineoverridevirtual

Definition at line 62 of file TopRecoilHook.cxx.

{return m_doTopRecoil;}

doVetoFSREmission()

virtual bool Pythia8::TopRecoilHook::doVetoFSREmission ( int  sizeOld, const Event &  event, int  iSys, bool  inResonance  )

inlineoverridevirtual

Definition at line 65 of file TopRecoilHook.cxx.

                                               {
    
      // Check that we are inside a resonance decay.
      if (!inResonance) return false;
 
      // Check that it is a top decay. 
      int iTop = partonSystemsPtr->getInRes(iSys);
      if (iTop == 0 || event[iTop].idAbs() != 6) return false;
    
      // Skip first emission, where ME corrections are already made.
      int sizeOut = partonSystemsPtr->sizeOut(iSys);
      if (sizeOut == 2) return false;
    
      // Location of trial new particles: radiator, emitted, recoiler.
      int iRad = sizeOld;
      int iEmt = sizeOld + 1;
      int iRec = sizeOld + 2;
    
      // The above partons are after emission;
      // alternatively use the ones before.
      if (m_useOldDipole) {
    iRad = event[iRad].mother1();
    iRec = event[iRec].mother1();
      }
    
      // Check if newly emitted gluon matches (anti)top colour line.
      if (event[iEmt].id() != 21) return false;
      if (event[iTop].id() == 6) {
    if (event[iEmt].col() != event[iTop].col()) return false;
      } else {
    if (event[iEmt].acol() != event[iTop].acol()) return false;
      }
    
      // Recoiler should now be a W, else something is wrong.
      if (event[iRec].idAbs() != 24) {
    cout << " ERROR: recoiler is " << event[iRec].id() << endl;
    return false;
      }
    
      // Denominator: eikonal weight with W as recoiler.
      double pRadRec = event[iRad].p() * event[iRec].p();
      double pRadEmt = event[iRad].p() * event[iEmt].p();
      double pRecEmt = event[iRec].p() * event[iEmt].p();
      double wtW = 2. * pRadRec / (pRadEmt * pRecEmt)
    - pow2(event[iRad].m() / pRadEmt);
      // If m_recoilDeadCone = on, include W mass term in denominator.
      if (m_recoilDeadCone) wtW -= pow2(event[iRec].m() / pRecEmt);
 
      // Numerator: eikonal weight with top as recoiler.
      double pRadTop = event[iRad].p() * event[iTop].p();
      double pTopEmt = event[iTop].p() * event[iEmt].p();
      double wtT = 2. * pRadTop / (pRadEmt * pTopEmt)
    - pow2(event[iRad].m() / pRadEmt) - pow2(event[iTop].m() / pTopEmt);
    
      // Histogram weight ratio.
      m_wtCorr->fill( wtT / wtW );
    
      // List relevant properties.
      if (m_doList) {
    std::cout << "\n now event with sizeOld = " << sizeOld << ", iSys = "
          << iSys << ", sizeOut = " << sizeOut << scientific
          << setprecision(3)
          << ", weight with W = " << wtW << " and with t = " << wtT << std::endl;
    partonSystemsPtr->list();
    event.list();
      }
    
      // Accept/reject emission. Smooth suppression or step function.
      return (wtT < wtW * rndmPtr->flat());
    }

initAfterBeams()

virtual bool Pythia8::TopRecoilHook::initAfterBeams ( )

inlineoverridevirtual

Definition at line 47 of file TopRecoilHook.cxx.

                                           {
 
      // Switch off if not using simple showers or if recoilToColoured = on.
      bool recoilToColoured = settingsPtr->flag("TimeShower:recoilToColoured");
      if (recoilToColoured){
    m_doTopRecoil=false;
    std::cout << "  TopRecoilHook should not be used with RecoilToColoured=on; disabling"<< std::endl;
      }
      // Flag if W mass term is already accounted for (true) or not (false).
      m_recoilDeadCone        = settingsPtr->flag("TimeShower:recoilDeadCone");
      // All ok.
      return true;
    }

Member Data Documentation

m_doList

bool Pythia8::TopRecoilHook::m_doList {}

private

Definition at line 141 of file TopRecoilHook.cxx.

m_doTopRecoil

bool Pythia8::TopRecoilHook::m_doTopRecoil {}

private

Definition at line 141 of file TopRecoilHook.cxx.

m_recoilDeadCone

bool Pythia8::TopRecoilHook::m_recoilDeadCone {}

private

Definition at line 141 of file TopRecoilHook.cxx.

m_useOldDipole

bool Pythia8::TopRecoilHook::m_useOldDipole {}

private

Definition at line 141 of file TopRecoilHook.cxx.

m_wtCorr

Hist* Pythia8::TopRecoilHook::m_wtCorr {}

private

Definition at line 142 of file TopRecoilHook.cxx.

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

• TopRecoilHook.cxx