Jet quenching theory using perturbative QCD is extended to include (1) elastic as well as (2) inelastic parton energy losses and (3) jet path length fluctuations. The extended theory is applied to non-photonic single electron production in central Au+Au collisions at √ s = 200 AGeV. The three effects combine to significantly reduce the discrepancy between theory and current data without violating the global entropy bounds from multiplicity and elliptic flow data. We also check for consistency with the pion suppression data out to 20 GeV. Fluctuations of the jet path lengths in realisitic geometry and the difference between the widths of fluctuations of elastic and inelastic energy loss are essential to take into account.

This writeup is a compilation of the predictions for the forthcoming Heavy Ion Program at the Large Hadron Collider, as presented at the CERN Theory Institute ‘Heavy Ion Collisions at the LHC—Last Call for Predictions’, held from 14th May to 10th June 2007.

We review the currently available formalisms for radiative energy loss of a high-momentum parton in a dense strongly interacting medium. The underlying theoretical framework of the four commonly used formalisms is discussed and the differences and commonalities between the formalisms are highlighted. A quantitative comparison of the single-gluon emission spectra as well as the energy-loss distributions is given for a model system consisting of a uniform medium with a fixed length of L = 2 fm and L = 5 fm (the "Brick"). Sizable quantitative differences are found. The largest differences can be attributed to specific approximations that are made in the calculation of the radiation spectrum.

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