BABAR C++ Course Running the Examples - HEPHY

Find D 0 sFind more D 0 and D*Find all the D 0 –> Kπ candidatesHepAList D0s;Combiner D0comb1(&kaons, &pions);while ( t = D0comb1.next() ) {if (t->charge() != 0.0) continue;if (fabs(t->mass() - d0Mass) > 0.2) continue;D0s.append(new AsTrack(*t));}• D0comb1 is initialized with two different lists• D0comb1.next() doespicks next track from kaon listlocks the trackpicks next unlocked track from pion listcreate and return pointer to new track which is sum• thus a measured track is never used twice in onecombination• note we must make copy of trackFind D 0 ->Kππ 0Combiner D0comb2(&kaons, &pions, &piZeros);while ( t = D0comb2.next() ) {if (t->charge() != 0.0) continue;if (fabs(t->mass() - d0Mass) > 0.2) continue;D0s.append(new AsTrack(*t));}Find D *HepAList Dstars;Combiner DsComb(&D0s, &pions);while ( t = DsComb.next() ) {if (fabs(t->mass() - dStarMass) > 0.2) continue;Dstars.append(new AsTrack(*t));}• Combiner allows variable number of arguments• D 0 –> Kπ and D 0 –> Kππ 0 go into same D0s list• Locking a track from D0s list, will lock all itschildren• note that the while loops are no more complex thenthe previous onesBABAR C++ Course 156 Paul F. KunzBABAR C++ Course 157 Paul F. Kunz