Eur. Phys. J. C (2015) 75: 461
https://doi.org/10.1140/epjc/s10052-015-3684-2

Regular Article - Theoretical Physics

The midpoint between dipole and parton showers

SLAC National Accelerator Laboratory, Menlo Park, CA, 94025, USA

^* e-mail: shoeche@slac.stanford.edu

Received: 17 June 2015
Accepted: 16 September 2015
Published online: 28 September 2015

Abstract

We present a new parton-shower algorithm. Borrowing from the basic ideas of dipole cascades, the evolution variable is judiciously chosen as the transverse momentum in the soft limit. This leads to a very simple analytic structure of the evolution. A weighting algorithm is implemented that allows one to consistently treat potentially negative values of the splitting functions and the parton distributions. We provide two independent, publicly available implementations for the two event generators Pythia and Sherpa.