Jet fragmentation measurements in p+Pb collisions with ATLAS

roton-nucleus collisions have been studied to provide baseline expectations for hard processes in heavy ion collisions. The rates of such processes could be modified compared to the expectation from binary scaled pp reference through nuclear modifications of parton distribution functions. The measurements of jets in minimum bias p+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$=5.02 TeV show slight deviations from the binary scaling in line with expectations based on nuclear parton distribution functions tuned to existing world data. Measurement of charged particles at high $p_\mathrm{T}$ (above 30 GeV) show an increase in yields with respect to the expectation from binary scaling which is larger then any deviations seen in the jet measurements. Since particles at these $p_\mathrm{T}$ arise from jet production, these measurements could be an evidence for modification of the jet fragmentation in p+Pb collisions compared to pp collisions. We will present measurements of the jet internal structure in p+Pb collisions spanning the jet $p_\mathrm{T}$ interval from 45 GeV to 260 GeV. The fragmentation functions measured in $\sqrt{s}$=2.76 TeV pp collisions were extrapolated to $\sqrt{s}$ = 5.02 TeV in order to provide a comparison for the p+Pb fragmentation functions.