Pythia8::TopRecoilHook Class Reference

#include <TopRecoilHook.h>

Inheritance diagram for Pythia8::TopRecoilHook:

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

Private Attributes
bool	doList
bool	doTopRecoil
bool	recoilDeadCone
bool	useOldDipole
Hist *	wtCorr

Detailed Description

Definition at line 21 of file TopRecoilHook.h.

Constructor & Destructor Documentation

TopRecoilHook()

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

inline

Definition at line 27 of file TopRecoilHook.h.

References doList, doTopRecoil, useOldDipole, and wtCorr.

                                                                                                 {
      doTopRecoil = doTopRecoilIn;
      useOldDipole = useOldDipoleIn;
      doList = doListIn;
      // Constructor also creates some histograms for analysis inside User Hook.
      wtCorr = new Hist("corrective weight", 100, 0., 2.);
    }

~TopRecoilHook()

Pythia8::TopRecoilHook::~TopRecoilHook ( )

inlineoverride

Definition at line 36 of file TopRecoilHook.h.

References wtCorr.

{ delete wtCorr; }

Member Function Documentation

canVetoFSREmission()

bool Pythia8::TopRecoilHook::canVetoFSREmission ( )

inlineoverride

Definition at line 51 of file TopRecoilHook.h.

References doTopRecoil.

{ return doTopRecoil; }

doVetoFSREmission()

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

inlineoverride

Definition at line 54 of file TopRecoilHook.h.

References cuy::col, doList, visualization-live-secondInstance_cfg::m, conifer::pow2(), recoilDeadCone, useOldDipole, and wtCorr.

                                                                                                 {
      // 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 (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) {
        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 recoilDeadCone = on, include W mass term in denominator.
      if (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.
      wtCorr->fill(wtT / wtW);

      // List relevant properties.
      if (doList) {
        partonSystemsPtr->list();
        event.list();
      }

      // Accept/reject emission. Smooth suppression or step function.
      return (wtT < wtW * rndmPtr->flat());
    }

initAfterBeams()

bool Pythia8::TopRecoilHook::initAfterBeams ( )

inlineoverride

Definition at line 39 of file TopRecoilHook.h.

References doTopRecoil, and recoilDeadCone.

                                   {
      // Switch off if recoilToColoured = on.
      bool recoilToColoured = settingsPtr->flag("TimeShower:recoilToColoured");
      if (recoilToColoured)
        doTopRecoil = false;
      // Flag if W mass term is already accounted for (true) or not (false).
      recoilDeadCone = settingsPtr->flag("TimeShower:recoilDeadCone");
      // All ok.
      return true;
    }

Member Data Documentation

doList

bool Pythia8::TopRecoilHook::doList

private

Definition at line 127 of file TopRecoilHook.h.

Referenced by doVetoFSREmission(), and TopRecoilHook().

doTopRecoil

bool Pythia8::TopRecoilHook::doTopRecoil

private

Definition at line 127 of file TopRecoilHook.h.

Referenced by canVetoFSREmission(), initAfterBeams(), and TopRecoilHook().

recoilDeadCone

bool Pythia8::TopRecoilHook::recoilDeadCone

private

Definition at line 127 of file TopRecoilHook.h.

Referenced by doVetoFSREmission(), and initAfterBeams().

useOldDipole

bool Pythia8::TopRecoilHook::useOldDipole

private

Definition at line 127 of file TopRecoilHook.h.

Referenced by doVetoFSREmission(), and TopRecoilHook().

wtCorr

Hist* Pythia8::TopRecoilHook::wtCorr

private

Definition at line 128 of file TopRecoilHook.h.

Referenced by doVetoFSREmission(), TopRecoilHook(), and ~TopRecoilHook().