Studies with gamma-jet

Flavour composition in gamma-jet?

• A understanding of flavour composition in gamma-jet sample is important for the SLT and b-jet energy scale?
• SLT analysis assume that flavour composition in gamma-jet sample is same as that in W+jets (as a SLT reviewer)
• For b-jet energy scale using gamma-bjet balance, a flavour composition for tagged jets is required.

B jet energy scale using gamma-bjet balance?

• Initial investigation shows that this method is a promising, but cetainly it requires a good understanding

of flavour composition on tagged jets (especially charm and gluon jets)
• See a talk at Jet Corr. Meeting, Dec. 1, 2004
• Does a b jet respone with no SLT channel agree with light quark jet response? by Mel Shochet
• Why is a tagging rate from gluon jet much higher that that from light quark jets? by Tommaso Dorigo
• Updated plots with Pythia "jqcdfh" sample (Feb. 10, 2006)
• Flavour composition with/out b-tagging
• Pt balence between photon and different flavoured jet (using HEPG info)
• Pt balence between photon and taggable (or tagged ) jet
• Delta phi between photon and different flavoured jet

Difference in gamma-jet balance between Pythia and Herwig?

• A gamma-jet balance between Pythia and Herwig shows very difference response,

which could be a big systematic for our jet energy corrections (very important for top mass measurement).
I have few good candiates for the source of this difference.