Use Analysis package
The Analysis module implements all tools needed for:
- Selection the final-state-particles reconstructed in the detector
- Construction arbitrary decay tree
- Imposing selection criteria
- Applying kinematic fit to the decay tree (TODO)
- Saving flat ntuple for the selected candidates
The decay language
An easy to read and to write string description of particle decay is used in the Analysis package. Particle names correspond to EvtGen naming scheme. The following strings are valid decay expressions:
"D0" "D0 -> K- pi+" "D0 -> [rho0 -> pi+ pi-] pi0"
As can be seen from the examples, a decay may or may not contain right-hand side. Left-hand and right-hand sides are separated by arrow "->". Spaces around the arrow are optional. Nested decays are expressed with square brackets.
Particle in a decay can have a label:
Here "lowpt" is a label. Labels allow working with different particle lists of the same type. For example:
"D*+ -> [D0 -> K- pi+] pi+:lowpt"
Finally, particle in a decay can be selected with the "^" symbol:
"D0 -> ^K- ^pi+"
Here "K-" and "pi+" are selected. This syntax is used to connect ntuple variables and particles as shown below.
The cuts language
The simplest way to make an analysis joboption is using the AuroraMaster interface with the Analysis component.