Event:
- eventID
True Track:
- charge (gChanrge)
- momentum (gpx, gpy, gpz)
- vertex (gvx, gvy, gvz)
- station1 (gx_st1, gy_st1, gz_st1, gpx_st1, gpy_st1, gpz_st1)
- station3 (gx_st3, gy_st3, gz_st3, gpx_st3, gpy_st3, gpz_st3)
Hit:
- hitID
- hit_trackID
- processID
- detectorID
- elementID
- driftDistance
- tdcTime
Reco Variables:
- charge (rec_charge)
- momentum (rec_px, rec_py, rec_pz)
- vertex (rec_vx, rec_vy, rec_vz)
- station1 (rec_x_st1, rec_y_st1, rec_z_st1, rec_px_st1, rec_py_st1, rec_pz_st1)
- station3 (rec_x_st3, rec_y_st3, rec_z_st3, rec_px_st3, rec_py_st3, rec_pz_st3)
- dimuon vertex (rec_dimu_vx, rec_dimu_vy, rec_dimu_vz)
- dimuon momentum (rec_dimu_px, rec_dimu_py, rec_dimu_pz)
- dimuon mass (rec_dimu_mass)
- dimuon xF, x1, x2 (rec_dimu_xf, rec_dimu_x1, rec_dimu_x2)
| Source Flag | Description |
|---|---|
| 1 | Target |
| 2 | Dump |
| 3 | Gap |
| Process | Description |
|---|---|
| 11 | DY (mu⁺) |
| 12 | J/ψ (mu⁺) |
| 13 | ψ' (mu⁺) |
| 14 | Single (mu⁺) |
| 21 | DY (mu⁻) |
| 22 | J/ψ (mu⁻) |
| 23 | ψ' (mu⁻) |
| 24 | Single (mu⁻) |
An example of how to access the event, track, and hit level information, as well as how to decode the processID to obtain the processID and sourceFlag.
import ROOT
def decode_source_flag(encoded):
return (encoded >> 5) & 0x3 # Extract bits 5-6
def decode_process_id(encoded):
return encoded & 0x1F # Extract lower 5 bits
file = ROOT.TFile("RUS.root")
tree = file.Get("tree")
for event in tree:
print("EventID:", event.eventID)
for i in range(len(event.gpz)):
#print track level information
print("true pz of the track: ", event.gpz[i] )
print("charge of the track: ", event.gCharge[i] )
for j in range(len(event.hit_trackID)):
#check for the track id. When the track id matches with the track id at the hit level, we access the hit information.
if event.hit_trackID[j] != trackID:
continue
hit_id = event.hitID[j]
hit_trackid = event.hit_trackID[j]
encoded_value = event.processID[j]
process_id = decode_process_id(encoded_value) #decoding the process_id
source_flag = decode_source_flag(encoded_value) #decoding the source_flag
print("hitID:", hit_id)
print("hit_trackID:", hit_trackid)
print("Encoded value:", encoded_value)
print("Decoded Process ID:", process_id)
print("Decoded Source Flag:", source_flag)