Coherent Showers In Resonance Decays Using VINCIA

by Dr Helen Brooks (Monash University)

Wednesday 5 Jun 2019, 11:00 → 12:00 Europe/Zurich

U2 - room 4066 (located on 4th floor, in the transition between buildings U1 and U2; alternative room name: U1-15) (Dipartimento di Fisica G. Occhialini, U2, Università degli Studi di Milano-Bicocca)

Monte Carlo event generators play an indispensable role in the direct measurement of resonances produced at hadron colliders. In traditional parton showers, coloured resonances and their decay products radiate independently. This approach fails to take into account interference between emissions from the initial-state resonance (in the narrow-width approximation) and the colour-connected final-state leg. Including these coherence effects modifies the amount of radiation produced and can affect the shape of distributions that are used in the reconstruction of the resonance.

In this talk, we describe a new implementation of coherent radiation from coloured resonances for VINCIA, an antenna-shower plug-in to the PYTHIA 8 Monte Carlo event generator. We present results matched to next-to-leading order accuracy with POWHEG for top quark pair production, and discuss observables relevant for the measurement of the top quark mass.

milan_resdecays.pdf