Abstract.
As an example of using Bayesian statistics in searches for new physics at the LHC, we present a calculation of Bayes factors for the erstwhile digamma resonance (\(\digamma\)) versus the SM in light of ATLAS 8 TeV 20.3/fb, 13 TeV 3.2/fb and 13 TeV 15.4/fb data. We matched, wherever possible, parameterisations in the ATLAS analysis. We calculated that the plausibility of the \(\digamma\) versus the Standard Model increased by about eight in light of the 8 TeV 20.3/fb and 13 TeV 3.2/fb ATLAS data, somewhat justifying interest in \(\digamma\) models. All told, however, in light of 15.4/fb data, the \(\digamma\) was disfavoured by about 0.7. We argue that Bayes factors could play an important role in future anomalies by clarifying the plausibility of new physics and sidestepping look-elsewhere effects.
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Fowlie, A. Bayes factor of the ATLAS diphoton excess: Using Bayes factors to understand anomalies at the LHC. Eur. Phys. J. Plus 132, 46 (2017). https://doi.org/10.1140/epjp/i2017-11340-1
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DOI: https://doi.org/10.1140/epjp/i2017-11340-1