Macro used /star/u/jkb03669/PID6.txt

Figure 1.   Ideal TOF (1/speed vs momentum) plot. (Generated by Zhangbou Xu)

Figure 2.    No cuts applied. Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Figure 3.    Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Cuts: At least one TPC track vertex matched to the TOF vertex.

          vertices.mNTracksUsed<10

          pPairs.tr1.charge != pPairs.tr2.charge

          vertices.mPosition.mX3<50

          0.05<pPairs.tr1(2).eta<1.5

          pPairs.pPt<0.15

Figure 4.     Assuming electron through TPC cuts alone: Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Cuts:  At least one TPC track vertex matched to the TOF vertex.

          vertices.mNTracksUsed<10

          pPairs.tr1.charge != pPairs.tr2.charge

          Abs(vertices.mPosition.mX3)<50

          0.05<Abs(pPairs.tr1(2).eta)<1.5

          pPairs.pPt<0.15

          Abs(pPairs.tr1(2).nSigmaEl)<1

Figure 5.     Assuming pion through TPC cuts alone: Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Cuts:  At least one TPC track vertex matched to the TOF vertex.

          vertices.mNTracksUsed<10

          pPairs.tr1.charge != pPairs.tr2.charge

          Abs(vertices.mPosition.mX3)<50

          0.05<Abs(pPairs.tr1(2).eta)<1.5

          pPairs.pPt<0.15

          Abs(pPairs.tr1(2).nSigmaPi)<1

Figure 6.     Assuming kaon through TPC cuts alone: Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Cuts:  At least one TPC track vertex matched to the TOF vertex.

          vertices.mNTracksUsed<10

          pPairs.tr1.charge != pPairs.tr2.charge

          Abs(vertices.mPosition.mX3)<50

          0.05<Abs(pPairs.tr1(2).eta)<1.5

          pPairs.pPt<0.15

          Abs(pPairs.tr1(2).nSigmaK)<1

Figure 7.     Assuming proton through TPC cuts alone: Left TOF(1/speed vs momentum). Right TPC(dE/dx vs momentum).

Cuts:  At least one TPC track vertex matched to the TOF vertex.

          vertices.mNTracksUsed<10

          pPairs.tr1.charge != pPairs.tr2.charge

          Abs(vertices.mPosition.mX3)<50

          0.05<Abs(pPairs.tr1(2).eta)<1.5

          pPairs.pPt<0.15

          Abs(pPairs.tr1(2).nSigmaP)<1

Problem was discovered with my coding for matching the momentum and the 1/speed data points. Essentially, the plots were generated by random designation between the two variables in all but Figure 1 (not mine). Probability created some of the ordered bands observed while the random designation created the distortion. This explains why in Figures 4-7 the TOF represents many more particles outside of their expected regions than we expect. We expect some contamination of other particles (hence why the TOF is necessary for a cleaner PID) but much more is observed in unexpected regions than there should be.