Mattione Update 06202011

b1pi Overview

• Generated 10000 X(2000) -> b₁π^-; events following the instructions here.
• Decay chain:

 gamma p -> p X(2000)0
               |
               |-> b1(1235)+ π-
                    |
                    |-> ω π+
                          |
                          |-> ρ0 π0
                               |   |-> γ γ
                               |
                               |-> π+ π-

b1pi Event Count

# Generated events = 10000

# Events with 2+ photons = 9660
# Events with 2+ π+'s = 7642
# Events with 2+ π-'s = 8156
# Events with 2+ protons = 1040 (should only be 1 !!)
# Events with enough tracks for the X (2+ photons, 2+ π+'s, 2+ π-'s) = 6076

b1pi Invariant Masses

Classes

Current Class Structure

                                    DPhysicsEvent
                                         |
                               vector < DParticleSet >
                                  /      |       \
 vector < DVertex::shower_info_t >    DVertex     vector < vector < DVertex::track_info_t > > (one for each charged particle id)
                                    /         \
   vector < DVertex::shower_info_t >           vector < vector < DVertex::track_info_t > >
              /                \                                /         |           \
         DBCALShower       DFCALShower                     tproj    DTrackTimeBased    FOM

* DVertex::shower_info_t is a class that inherits from DKinematicData
* DVertex::track_info_t is a struct
* vector < vector < DVertex::track_info_t > > : for each DTrackCandidate there are multiple fit hypotheses, corresponding to different particle masses

Problems:
 - Storing final track information in DVertex subclasses is non-intuitive (especially the 2D track_info_t vector).
 - DVertex::track_info_t does not inherit from JObject: cannot add associated objects (DTOFPoint, etc.)
 - Cannot call JEventLoop->Get(DVertex::track_info_t) (No factories for the particles)
 - All neutral particles are assumed to be photons (could be neutrons, such as from Lambda decay). 

Proposed Class Structure

                                    DPhysicsEvent
                                         |
                               vector < DParticleSet >
                                  /      |       \
          vector < DNeutralTrack >    DVertex     vector < DChargedTrack >
                                    /         \
            vector < DNeutralTrack >           vector < DChargedTrack >
                        |                                      |
       vector < DNeutralTrackHypothesis >    vector < DChargedTrackHypothesis >


* DVertex::shower_info_t is a class that inherits from DKinematicData and contains pointers to DBCALShower and DFCALShower objects
*DVertex::track_info_t is a struct that contains a DTrackTimeBased object, along with the projected time at the vertex and the FOM