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diff --git a/Shower/Default/Decay_QTildeShowerKinematics1to2.cc b/Shower/Default/Decay_QTildeShowerKinematics1to2.cc
--- a/Shower/Default/Decay_QTildeShowerKinematics1to2.cc
+++ b/Shower/Default/Decay_QTildeShowerKinematics1to2.cc
@@ -1,145 +1,145 @@
// -*- C++ -*-
//
// Decay_QTildeShowerKinematics1to2.cc is a part of Herwig - A multi-purpose Monte Carlo event generator
// Copyright (C) 2002-2011 The Herwig Collaboration
//
// Herwig is licenced under version 2 of the GPL, see COPYING for details.
// Please respect the MCnet academic guidelines, see GUIDELINES for details.
//
//
// This is the implementation of the non-inlined, non-templated member
// functions of the Decay_QTildeShowerKinematics1to2 class.
//
#include "Decay_QTildeShowerKinematics1to2.h"
#include "ThePEG/PDT/EnumParticles.h"
#include "Herwig/Shower/SplittingFunctions/SplittingFunction.h"
#include "Herwig/Shower/Base/ShowerParticle.h"
#include <cassert>
#include "Herwig/Shower/ShowerHandler.h"
#include "Herwig/Shower/Base/Evolver.h"
#include "Herwig/Shower/Base/PartnerFinder.h"
#include "Herwig/Shower/Base/ShowerModel.h"
#include "Herwig/Shower/Base/KinematicsReconstructor.h"
#include "Herwig/Shower/Base/ShowerVertex.h"
using namespace Herwig;
void Decay_QTildeShowerKinematics1to2::
updateChildren(const tShowerParticlePtr parent,
const ShowerParticleVector & children,
ShowerPartnerType::Type partnerType,
bool massVeto) const {
assert(children.size() == 2);
// calculate the scales
splittingFn()->evaluateDecayScales(partnerType,scale(),z(),parent,
children[0],children[1]);
// set the maximum virtual masses
vector<long> ids(3);
ids[0] = parent->id();
ids[1] = children[0]->id();
ids[2] = children[1]->id();
const vector<Energy> & virtualMasses = SudakovFormFactor()->virtualMasses(ids);
Energy2 q2 = sqr(virtualMasses[0])-(1.-z())*sqr(scale());
children[0]->virtualMass(sqrt(q2));
if(massVeto) {
children[1]->scales().Max_Q2 = (1.-z())/z()*(z()*sqr(virtualMasses[0])-q2);
}
// determine alphas of children according to interpretation of z
const ShowerParticle::Parameters & params = parent->showerParameters();
ShowerParticle::Parameters & child0 = children[0]->showerParameters();
ShowerParticle::Parameters & child1 = children[1]->showerParameters();
child0.alpha = z() * params.alpha;
child1.alpha = (1.-z()) * params.alpha;
child0.ptx = pT() * cos(phi()) + z()* params.ptx;
child0.pty = pT() * sin(phi()) + z()* params.pty;
child0.pt = sqrt( sqr(child0.ptx) + sqr(child0.pty) );
child1.ptx = -pT() * cos(phi()) + (1.-z()) * params.ptx;
child1.pty = -pT() * sin(phi()) + (1.-z()) * params.pty;
child1.pt = sqrt( sqr(child1.ptx) + sqr(child1.pty) );
// set up the colour connections
splittingFn()->colourConnection(parent,children[0],children[1],partnerType,false);
// make the products children of the parent
parent->addChild(children[0]);
parent->addChild(children[1]);
// set the momenta of the children
for(ShowerParticleVector::const_iterator pit=children.begin();
pit!=children.end();++pit) {
setMomentum(*pit,true);
}
}
void Decay_QTildeShowerKinematics1to2::
reconstructParent( const tShowerParticlePtr, const ParticleVector &) const {
throw Exception() << "Decay_QTildeShowerKinematics1to2::reconstructParent not implemented"
<< Exception::abortnow;
}
void Decay_QTildeShowerKinematics1to2::
reconstructLast(const tShowerParticlePtr last, Energy mass) const {
// set beta component and consequently all missing data from that,
// using the nominal (i.e. PDT) mass.
Energy theMass = mass>ZERO ? mass : last->data().constituentMass();
last->showerParameters().beta=
(sqr(theMass) + sqr(last->showerParameters().pt)
- sqr( last->showerParameters().alpha )*pVector().m2())
/ ( 2.*last->showerParameters().alpha*p_dot_n() );
// set that new momentum
last->set5Momentum( sudakov2Momentum( last->showerParameters().alpha,
last->showerParameters().beta,
last->showerParameters().ptx,
last->showerParameters().pty) );
}
void Decay_QTildeShowerKinematics1to2::initialize(ShowerParticle & particle,PPtr) {
Lorentz5Momentum p, n, ppartner, pcm;
Frame frame;
assert(particle.perturbative()!=1);
// this is for the initial decaying particle
if(particle.perturbative()==2) {
p = particle.momentum();
ShowerParticlePtr partner=particle.partner();
Lorentz5Momentum ppartner(partner->momentum());
- // reomved to make inverse recon work properly
+ // removed to make inverse recon work properly
//if(partner->thePEGBase()) ppartner=partner->thePEGBase()->momentum();
pcm=ppartner;
Boost boost(p.findBoostToCM());
pcm.boost(boost);
n = Lorentz5Momentum( ZERO,0.5*p.mass()*pcm.vect().unit());
n.boost( -boost);
frame = Rest;
}
else {
tShoKinPtr kin=dynamic_ptr_cast<ShowerParticlePtr>(particle.parents()[0])
->showerKinematics();
p = kin->getBasis()[0];
n = kin->getBasis()[1];
frame = kin->frame();
}
setBasis(p,n,frame);
}
void Decay_QTildeShowerKinematics1to2::updateParent(const tShowerParticlePtr parent,
const ShowerParticleVector & children,
ShowerPartnerType::Type) const {
IdList ids(3);
ids[0] = parent->id();
ids[1] = children[0]->id();
ids[2] = children[1]->id();
const vector<Energy> & virtualMasses = SudakovFormFactor()->virtualMasses(ids);
children[0]->virtualMass(sqrt(sqr(virtualMasses[0])-(1.-z())*sqr(scale())));
if(children[1]->children().empty()) children[1]->virtualMass(virtualMasses[2]);
// compute the new pT of the branching
Energy2 pt2=(1.-z())*(z()*sqr(virtualMasses[0])-sqr(children[0]->virtualMass()))
-z()*sqr(children[1]->virtualMass());
if(pt2>ZERO) {
pT(sqrt(pt2));
}
else {
parent->virtualMass(ZERO);
}
}

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