PrimEx at GlueX

There is an interest in continuing the PrimEx physics program with the GlueX detector with the 12 GeV beam. One can find links to meetings and minutes for a series of GlueX and PrimEx meetings here.

Physics Topics

• Measurement of the γγ width of the η and η' using Primakoff Production
• Measurement of rare η decay branching fractions

Monte Carlo Studies

Output Data File Format

The reconstructed and analyzed data events are written out in a ROOT tree with the name "event". The tree contains several series of variable length arrays. A description of the entries appears below:

• n: The number of reconstructed photons in the FCAL
• E[n], px[n], py[n], pz[n]: The four momentum of the nth reconstructed photon
• neuETot: The total reconstructed energy in the FCAL
• M: The invariant mass of all FCAL photons
• nNeuGen: The number of generated neutral particles
• genNeuE[nNeuGen], genNeuPx[nNeuGen], genNeuPy[nNeuGen], genNeuPz[nNeuGen]: The four momentum of the nNeuGenth generated neutral
• neuType[nNeuGen]: The GEANT particle type of the nNeuGenth particle
• nChGen: The number of generated charged particles
• genChE[nChGen], genChPx[nChGen], genChPy[nChGen], genChPz[nChGen]: The four momentum of the nChGenth generated neutral
• chType[nChGen]: The GEANT particle type of the nChGenth particle