Rivet analyses
Differential branching ratio, polarization and asymmetries in B → K(*)ℓ+ℓ−
Experiment: BELLE (KEKB)
Inspire ID: 817326
Status: VALIDATED NOHEPDATA
Authors: - Peter Richardson
References: - Phys.Rev.Lett. 103 (2009) 171801
Beams: * *
Beam energies: ANY
Run details: - Any process production B0 and B+ mesons, oeiginally Upsilon(4S) decay
Measurement of the differential branching ratio, polarization and asymmetries in B → K(*)ℓ+ℓ− as a function of q2.
Source
code:BELLE_2009_I817326.cc
// -*- C++ -*-
#include "Rivet/Analysis.hh"
#include "Rivet/Projections/UnstableParticles.hh"
#include "Rivet/Projections/DecayedParticles.hh"
namespace Rivet {
/// @brief B -> K(*) l+ l-
class BELLE_2009_I817326 : public Analysis {
public:
/// Constructor
RIVET_DEFAULT_ANALYSIS_CTOR(BELLE_2009_I817326);
/// @name Analysis methods
/// @{
/// Book histograms and initialise projections before the run
void init() {
// Initialise and register projections
UnstableParticles ufs = UnstableParticles(Cuts::abspid==511 or
Cuts::abspid==521);
declare(ufs, "UFS");
DecayedParticles BB(ufs);
BB.addStable( 443);
BB.addStable(100443);
BB.addStable(PID::K0S);
BB.addStable(PID::K0L);
BB.addStable( 313);
BB.addStable(-313);
BB.addStable( 323);
BB.addStable(-323);
declare(BB, "BB");
for(unsigned int ix=0;ix<2;++ix) {
book(_p_FL[ix],1,1+ix,2);
for(unsigned int iy=0;iy<2;++iy) {
book(_h_br[ix][iy],1+ix,1+iy,1);
book(_p_FB[ix][iy],1+ix,1+iy,4);
for(unsigned int iz=0;iz<2;++iz)
book(_h_br_B[ix][iy][iz],
"TMP/h_br_"+toString(ix+1)+"_"+toString(iy+1)+"_"+toString(iz+1),
refData(1+ix,1+iy,1));
}
};
for(unsigned int ix=0;ix<3;++ix)
book(_c[ix],"TMP/c_"+toString(ix+1));
}
/// Perform the per-event analysis
void analyze(const Event& event) {
static const map<PdgId,unsigned int> & mode1 = { { 321,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode1CC = { {-321,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode2 = { { 310,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode2CC = { { 130,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode3 = { { 321,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode3CC = { {-321,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode4 = { { 310,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode4CC = { { 130,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode5 = { { 323,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode5CC = { {-323,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode6 = { { 313,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode6CC = { {-313,1},{ 13,1}, {-13,1}};
static const map<PdgId,unsigned int> & mode7 = { { 323,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode7CC = { {-323,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode8 = { { 313,1},{ 11,1}, {-11,1}};
static const map<PdgId,unsigned int> & mode8CC = { {-313,1},{ 11,1}, {-11,1}};
DecayedParticles BB = apply<DecayedParticles>(event, "BB");
for(unsigned int ix=0;ix<BB.decaying().size();++ix) {
_c[0]->fill();
if(BB.decaying()[ix].abspid()==521) _c[1]->fill();
else _c[2]->fill();
int imode=0;
if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode1)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode1CC))) imode=0;
else if (BB.modeMatches(ix,3,mode2)||BB.modeMatches(ix,3,mode2CC)) imode=1;
else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode3)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode3CC))) imode=2;
else if (BB.modeMatches(ix,3,mode4) || BB.modeMatches(ix,3,mode4CC)) imode=3;
else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode5)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode5CC))) imode=4;
else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode6)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode6CC))) imode=5;
else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode7)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode7CC))) imode=6;
else if ((BB.decaying()[ix].pid()>0 && BB.modeMatches(ix,3,mode8)) ||
(BB.decaying()[ix].pid()<0 && BB.modeMatches(ix,3,mode8CC))) imode=7;
else continue;
int il = imode<2 || imode==4 || imode==5 ? 13 : 11;
const Particle & lp = BB.decayProducts()[ix].at(-il)[0];
const Particle & lm = BB.decayProducts()[ix].at( il)[0];
double qq = (lp.momentum()+lm.momentum()).mass2();
for(unsigned int iy=0;iy<2;++iy) {
if(imode<4) {
_h_br[1][iy]->fill(qq);
if(BB.decaying()[ix].abspid()==521)
_h_br_B[1][iy][0]->fill(qq);
else
_h_br_B[1][iy][1]->fill(qq);
}
else {
_h_br[0][iy]->fill(qq);
if(BB.decaying()[ix].abspid()==521)
_h_br_B[0][iy][0]->fill(qq);
else
_h_br_B[0][iy][1]->fill(qq);
}
}
// first boost to bottom frame
const LorentzTransform boost =
LorentzTransform::mkFrameTransformFromBeta(BB.decaying()[ix].momentum().betaVec());
FourMomentum plp = boost.transform(lp .momentum());
FourMomentum plm = boost.transform(lm .momentum());
FourMomentum pB = boost.transform(BB.decaying()[ix].momentum());
// lepton stuff
const LorentzTransform boost2 = LorentzTransform::mkFrameTransformFromBeta((plp+plm).betaVec());
plp = boost2.transform(plp);
double cTheta = plp.p3().unit().dot(boost .transform(pB ).p3().unit());
double AFB = cTheta>0 ? 1 : -1;
for(unsigned int iy=0;iy<2;++iy) {
if(imode<4) _p_FB[1][iy]->fill(qq,AFB);
else _p_FB[0][iy]->fill(qq,AFB);
}
// only K* for FL
if(imode<4) continue;
int iK = BB.decaying()[ix].abspid()==521 ? 323 : 313;
iK *= BB.decaying()[ix].pid()/BB.decaying()[ix].abspid();
const Particle & Kstar = BB.decayProducts()[ix].at( iK)[0];
FourMomentum pKstar = boost.transform(Kstar.momentum());
if(Kstar.children().size()!=2) continue;
Particle KK;
if(Kstar.abspid()==313) {
if(Kstar.children()[0].abspid()==321 &&
Kstar.children()[1].abspid()==211)
KK = Kstar.children()[0];
else if(Kstar.children()[1].abspid()==321 &&
Kstar.children()[0].abspid()==211)
KK = Kstar.children()[1];
else continue;
}
else {
if(Kstar.children()[0].abspid()==311 &&
Kstar.children()[1].abspid()==211)
KK = Kstar.children()[0];
else if(Kstar.children()[1].abspid()==311 &&
Kstar.children()[0].abspid()==211)
KK = Kstar.children()[1];
else if(Kstar.children()[0].abspid()==310 &&
Kstar.children()[1].abspid()==211)
KK = Kstar.children()[0];
else if(Kstar.children()[1].abspid()==310 &&
Kstar.children()[0].abspid()==211)
KK = Kstar.children()[1];
else if(Kstar.children()[0].abspid()==321 &&
Kstar.children()[1].abspid()==111 && il==11)
KK = Kstar.children()[0];
else if(Kstar.children()[1].abspid()==321 &&
Kstar.children()[0].abspid()==111 && il==11)
KK = Kstar.children()[1];
else continue;
if(KK.abspid()==311) {
if(KK.children().size()==1 && KK.children()[0].pid()==310)
KK = KK.children()[0];
else
continue;
}
}
FourMomentum pK = boost.transform(KK .momentum());
const LorentzTransform boost3 = LorentzTransform::mkFrameTransformFromBeta(pKstar.betaVec());
pK = boost3.transform(pK);
cTheta = pK.p3().unit().dot(boost .transform(pB ).p3().unit());
double FL = .5*(5.*sqr(cTheta)-1.);
for(unsigned int iy=0;iy<2;++iy) _p_FL[iy]->fill(qq,FL);
}
}
/// Normalise histograms etc., after the run
void finalize() {
// ratio of lifetimes
double rLife = 1./1.078;
for(unsigned int ix=0;ix<2;++ix) {
for(unsigned int iy=0;iy<2;++iy) {
scale(_h_br[ix][iy],0.5e7/ *_c[0]);
for(unsigned int il=0;il<2;++il) {
scale(_h_br_B[ix][iy][il],0.5e7/ *_c[il+1]);
if (il==0) scale(_h_br_B[ix][iy][il],rLife);
}
// A_I plots
Estimate1DPtr AI;
book(AI,1+ix,1+iy,3);
asymm(_h_br_B[ix][iy][1],_h_br_B[ix][iy][0],AI);
}
}
}
/// @}
/// @name Histograms
/// @{
Histo1DPtr _h_br[2][2],_h_br_B[2][2][2];
Profile1DPtr _p_FL[2],_p_FB[2][2];
CounterPtr _c[3];
/// @}
};
RIVET_DECLARE_PLUGIN(BELLE_2009_I817326);
}