Biased Showers - a common conceptual Framework for the Interpretation of High P_T Observables in Heavy-Ion Collisions

Abstract

After the start of the LHC, a plethora of novel observables for jet tomography in heavy-ion collisions has appeared. Many of these studies have yielded counter-intuitive null results of apparently unmodified jets, which have sparked (sometimes exotic) theoretical efforts to explain these findings. However, it has to be realized that almost all current high P_T observables measure conditional probabilities of events, not probabilities. Thus, the correct starting point for their theoretical understanding is Bayes' formula, and the biases introduced by the conditioning are crucial to understanding the outcome. Once this is introduced properly into the modelling process, the counter-intuitive results are seen to find a natural explanation in terms of various biases and the puzzles largely disappear. In this work, a conceptual framework to classify the various observables according to the types of bias they are sensitive to is presented and illustrated with a large number of case studies ranging from simple jet finding to 2+1 dihadron triggered correlations.

18 pages, 19 figures, 5 tables, submitted to PRC

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Cited by in corpus (17)

• Jet Structure in Heavy Ion Collisions
• Jet (de)coherence in Pb-Pb collisions at the LHC
• Disentangling Jet Modification in Jet Simulations and in Z+Jet Data
• Medium-induced modification of $Z$-tagged charged particle yields in Pb+Pb collisions at 5.02 TeV with the ATLAS detector
• Measurements of jet quenching using semi-inclusive hadron+jet distributions in pp and central Pb$-$Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02$ TeV
• In-medium jet shape from energy collimation in parton showers: Comparison with CMS PbPb data at 2.76 TeV
• Heavy-Flavour Jets in High-Energy Nuclear Collisions
• Parton splitting scales of reclustered large-radius jets in high-energy nuclear collisions
• Probing the in-medium $P_T$-broadening by $\gamma$+HF angular de-correlations
• Comparison of fragmentation functions for light-quark- and gluon-dominated jets from $pp$ and Pb+Pb collisions in ATLAS
• Charm energy loss and D-D correlations from a shower picture
• Flavor and path-length dependence of jet quenching from inclusive jet and γ-jet suppression
• Phenomenological study of the angle between jet axes in heavy-ion collisions
• Jet correlations - opportunities and pitfalls
• Measurement of away-side broadening with self-subtraction of flow in Au+Au collisions at $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV
• Studying the QGP with Jets at the LHC and RHIC
• Event-by-Event Simulations of Jet Modification Using the MATTER Event Generator