Radiative corrections and Monte Carlo tools for low-energy hadronic cross sections in $e^+e^-$ collisions

Europe/Zurich
KOL-F-101 (University of Zurich)

KOL-F-101

University of Zurich

Adrian Signer (PSI - Paul Scherrer Institut), Yannick Ulrich (University of Durham), Andrzej Kupsc, Graziano Venanzoni (University of Liverpool)
Description

This hybrid conference acts as a satellite event to the 5th workstop/thinkstart and aims to collect some community input and form new collaboration.

Participants
    • 14:00 15:30
      Introduction and overview
      • 14:00
        Overview $g-2$ 50m
        Speaker: Martin Hoferichter (Unversity of Bern)
      • 15:00
        Workstop/thinkstart activities: towards a NNLO MC generator for low-energy $e^+e^-\to$ hadrons 20m
        Speaker: Graziano Venanzoni (University of Liverpool)
    • 15:30 16:00
      Coffee break 30m
    • 16:00 17:50
      Experiments
    • 14:00 15:30
      Hadrons
    • 15:30 16:00
      Coffee break 30m
    • 16:00 16:30
      Hadrons
      • 16:00
        WP3: Processes with hadrons 20m
        Speaker: Peter Stoffer (UZH and PSI)
    • 16:30 18:00
      Loops in QED
      • 16:30
        WP1: leptonic processes at NNLO & beyond 15m
        Speaker: William Torres Bobadilla (Max-Planck-Institut für Physik)
      • 16:45
        WP2: Form factor contributions at N$^3$LO 15m
        Speaker: Tim Engel (Uni Freiburg)
      • 17:10
        $e^+e^-\to\gamma\gamma^*$ at two loops in massless QED 20m

        We present an analytic computation of $e^+e^-\to\gamma\gamma^*$ at two loops in massless QED. We reconstruct the analytic form of the amplitudes from numerical evaluations over finite fields. We express the integrals in a basis of Goncharov polylogarithms to obtain compact expressions. These contributions are required for N$^3$LO predictions of the inclusive process $e^+e^-\to\gamma^*$ and for NNLO corrections for ISR measurements of $e^+e^-\to\gamma\gamma^*$.

        Speaker: Ryan Moodie (Turin University)
    • 14:00 15:00
      Parton showers
      • 14:00
        WP4: parton shower 20m
        Speaker: Carlo Carloni Calame (INFN, Pavia (IT))
      • 14:30
        Photon splitting corrections to soft-photon resummation 20m

        In this talk I will motivate the importance of including QED corrections in a systematic and automated manner. I will present an algorithm to add photon-splitting corrections to the Yennie-Frautschi-Suura-style soft-photon resummation available in the Sherpa Monte-Carlo event generator. Then, I will introduce different lepton dressing strategies which incorporate further leptons and hadrons in addition to the customary photons, and discuss their sensitivity to dressing parameters such as the cone size. I will then present some results for academic and realistic setups.

        Speaker: Lois Flower (Durham University)
    • 15:00 16:10
      MUonE
    • 16:10 17:00
      Closing remarks and drinks 50m