20-27 July 2011
Alpes Congrès - Alpexpo
Europe/Paris timezone

Meaningful characterisation of perturbative theoretical uncertainties

21 Jul 2011, 09:30
15m
Bayard (Alpes Congrès - Alpexpo)

Bayard

Alpes Congrès - Alpexpo

Parallel session talk QCD QCD

Speaker

Nicolas Houdeau (LPTHE (CNRS - UPMC))

Description

We consider the problem of assigning a meaningful confidence to uncertainty estimates of perturbative series. We analyse the assumptions which are implicit in the conventional estimates made using renormalisation scale variations. We then formulate a Bayesian model that, given equivalent initial hypotheses, allows one to characterise a perturbative theoretical uncertainty in a rigorous way in terms of the confidence of an interval for the remainder of the series. We compare its outcome to the conventional uncertainty estimates in the simple case of the calculation of QCD corrections to the e+e- -> hadrons process. We find comparable results, but with important conceptual differences. This work represents a first step in the direction of a more comprehensive and rigorous handling of theoretical uncertainties in perturbative calculations used in high energy phenomenology.

Primary authors

Dr Matteo Cacciari (LPTHE Paris) Nicolas Houdeau (LPTHE (CNRS - UPMC))

Presentation Materials