Prof. Gavin Salam FRS

Abstract:

We present the report of the hadronic working group of the BOOST2010 workshop held at the University of Oxford in June 2010. The first part contains a review of the potential of hadronic decays of highly boosted particles as an aid for discovery at the LHC and a discussion of the status of tools developed to meet the challenge of reconstructing and isolating these topologies. In the second part, we present new results comparing the performance of jet grooming techniques and top tagging algorithms on a common set of benchmark channels. We also study the sensitivity of jet substructure observables to the uncertainties in Monte Carlo predictions.

Abstract:

The calculation of cross-sections at Next-to-Leading order in QCD involves the integration over the final state phase space in order to cancel the infra-red divergences. For the calculation of cross sections for jet observables in deep-inelastic scattering or at hadron-hadron colliders this integration requires the Monte Carlo generation of a large number of event weights, and must be repeated for any calculation with a different choice of parton densities within the proton or different choice of factorisation or renormalisation scale. This makes the full calculation with many of the available parton density function error sets, or any iterative fit of the parton densities themselves, prohibitive in terms of the processing time required. A method for the a posteriori inclusion of the parton densities in the calculation is presented. In this method, the Monte Carlo weights from the integration over the hard-subprocess phase space are stored in a look-up table so that the full calculation need be performed only once, after which the cross section can be obtained with any parton density set by a fast convolution with the stored weights. A detailed example from inclusive jet production at the LHC is presented. © Copyright owned by the author(s) under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike Licence.