#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

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.);
     }

Pythia8::TopRecoilHook::~TopRecoilHook ( )

inlineoverride

Definition at line 36 of file TopRecoilHook.h.

References wtCorr.

36 { delete wtCorr; }

Pythia8::TopRecoilHook::wtCorr

Hist * wtCorr

Definition: TopRecoilHook.h:128

Member Function Documentation

bool Pythia8::TopRecoilHook::canVetoFSREmission ( )

inlineoverride

Definition at line 51 of file TopRecoilHook.h.

References doTopRecoil.

51 { return doTopRecoil; }

Pythia8::TopRecoilHook::doTopRecoil

bool doTopRecoil

Definition: TopRecoilHook.h:127

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, funct::m, 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());
     }

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;
     }