Speaker
Description
Prompt-photon predictions with experimentally relevant isolation criteria retain a residual dependence on parton-to-photon fragmentation functions, whose phenomenological uncertainties remain only weakly constrained.
We present a pragmatic study of photon fragmentation functions extracted from Pythia parton-shower events and stored in an LHAPDF-compatible format.
We briefly review the role of photon fragmentation in perturbative QCD and then construct shower-level estimates of the flavour-dependent functions (D_{\gamma/i}(z,\mu_D)) as functions of the photon momentum fraction (z) and fragmentation scale (\mu_D).
The extracted distributions show the expected qualitative hierarchy between quark and gluon channels and an increasing fragmentation probability with scale.