Abstract
We present a simple parton-shower model that replaces the explicit angular ordering of the coherent branching formalism with a differentially accurate simulation of soft-gluon radiation by means of a non-trivial dependence of the splitting functions on azimuthal angles. We introduce a global kinematics mapping and provide an analytic proof that it satisfies the criteria for next-to leading logarithmic accuracy. In the new algorithm, initial and final state evolution are treated on the same footing. We provide an implementation for final-state evolution in the numerical code Alaric and present a first comparison to experimental data.
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Acknowledgments
We thank Andrea Banfi for pointing out that the relative difference between the parton-shower and the NLL result in figure 4 should decrease proportional to αs as αs → 0. The work of F. Herren and S. Höche was supported by the Fermi National Accelerator Laboratory (Fermilab), a U.S. Department of Energy, Office of Science, HEP User Facility. Fermilab is managed by Fermi Research Alliance, LLC (FRA), acting under Contract No. DE–AC02–07CH11359. F. Herren acknowledges support by the Alexander von Humboldt foundation. This work has received funding from the European Union’s Horizon 2020 research and innovation programme as part of the Marie Skłodowska-Curie Innovative Training Network MCnetITN3 (grant agreement no. 722104). F. Krauss acknowledges funding as Royal Society Wolfson Research fellow. F. Krauss and M. Schönherr are supported by the STFC under grant agreement ST/P001246/1. They would like to thank the Munich Institute for Astro-, Particle and BioPhysics (MIAPbP), funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy – EXC-2094 – 390783311, for hospitality while this publication was finalized. The work of M. Schönherr was supported by the Royal Society through a University Research Fellowship (URF\R1\180549) and an Enhancement Award (RGF\EA\181033, CEC19\100349, and RF\ERE\210397).
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Herren, F., Höche, S., Krauss, F. et al. A new approach to color-coherent parton evolution. J. High Energ. Phys. 2023, 91 (2023). https://doi.org/10.1007/JHEP10(2023)091
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DOI: https://doi.org/10.1007/JHEP10(2023)091