Lund Plane Reweighting for Jet Substructure Correction

Many searches for new phenomena at the LHC utilize boosted large radius jets which contain the showers of multiple partons from the hard process. Such jets can be distinguished from those produced by the shower of a single parton due to their multiple prongs of energy. Due to limitations of the simulation of these jets, they are typically calibrated using similar standard model proxies in available in data. However, this approach cannot be straightforwardly applied to jets with a large number of prongs because no standard model process produces jets with more than three prongs in sufficient quantities. This note presents a new technique for correcting the substructure modeling of boosted, multi-prong, large radius jets which can be applied to jets with large numbers of prongs. Data corresponding to an integrated luminosity of 138 fb$^{-1}$ collected by the CMS experiment between 2016-2018 at a center of mass energy of 13 TeV are analyzed to develop the technique and evaluate its performance. The technique is based on reclustering the jet's constituents into several subjets, such that each subjet captures a single prong, and separately correcting the radiation pattern of each subjet using a data-driven correction in the Lund jet plane. It is shown that the correction procedure improves the agreement between data and simulation in multiple different substructure observables of two and three pronged jets. This technique will enable future searches for high prong jets which were not possible with prior methods.