Chengping Shen Phys. Dept., University of Hawaii Check MC samples produced at MN and topology

Using Ψ(2S)→γη c, η c →ηπ + π - as example to check General selection: Good charged tracks select: Vr < 1.0cm, |Vz|<5.0cm, |cos θ |<0.93 Good photon select: Eraw >= 40MeV, N trk =2 and Σ Q =0 PID: pi: Prob(K) <Prob(pi) 4C Kinematic Fit, looping over all good photon candidates, select the combination with the minimum χ 2.

The gamma gamma distributions seem strange! (a) (b) (a): After kinematic fit (b): After kinematic fit and PID requirements

BOSS BOSS6.3.3 nightly_build has been released. Now we could do simulation, reconstruction at IHEP server. 2. The change is large, including generator, simulation, reconstruction, but such change is good: jobOptions files have been simplified. jobOption:TestRelease/run(TestRelease ) Environment setup:/afs/ihep.ac.cn/bes3/offline/sw/dist/boss/cmthome/ cmthome-nightly_build 3. Notice: the writing format for event selection has been changed largely(haixuan told me). We need to wait for see the RhoPi example for BOSS6.3.3

Event Topology You must output the “run” and “rec” into your ntp file. Then run the root program: anytopo.cxx

=============================== Decay Channel: No. 19 =============================== run number: event number: 128 track number: 28 itype number: J/psi a_ a_ pi pi eta pi pi pi gamma e gamma gamma gamma e gamma e gamma e gamma nan gamma pi rho pi pi gamma nan gamma e gamma nan gamma nan =============================== Decay Channel: No. 1 =============================== run number: event number: 3 track number: 18 itype number: J/psi anti-K pi K* K_S pi pi gamma e gamma e gamma e gamma nan K pi gamma e gamma e topo.mess