In the context of the PanScales parton shower project I will describe two advances in the development of final-state parton showers with controlled logarithmic accuracy. The first (arXiv:2011.10054) involves simple new algorithms to resolve the long-standing issue of incorrect subleading-colour contributions at leading logarithmic (LL) accuracy in dipole- and antenna-type showers, and also enables the PanScales showers to obtain full-colour NLL accuracy for many observables. The second (arXiv:2103.16526) concerns spin correlations, where we propose a spinor-product based implementation of the well-established Collins algorithm. We verify the logarithmic accuracy of the results with separate purely collinear calculations, using novel spin-sensitive jet observables that are of potential interest also for future experimental measurements.
|First author||Ludovic Scyboz|
|Collaboration / Activity||PanScales|