The hadronic vacuum polarization from lattice QCD at high precision

Europe/Zurich
online
Antoine Gérardin (Aix Marseille Univ, Université de Toulon, CNRS, CPT, Marseille, France), Davide Giusti (Universit\"at Regensburg, Fakult\"at f\"ur Physik, Regensburg, Germany), Vera Gülpers (School of Physics and Astronomy, University of Edinburgh, Edinburgh, United Kingdom), Kohtaroh Miura (Helmholtz-Institut Mainz, Johannes Gutenberg-Universit\"at Mainz, Mainz, Germany), Alejandro Vaquero Avilés-Casco (Department of Physics and Astronomy, University of Utah, Salt Lake City, USA)
Description

The anomalous magnetic moment of the muon is providing a persistent hint for new physics, in the form of an intriguing 3 - 4σ tension between Standard Model (SM) theory and experiment. We expect the Fermilab Muon g-2 experiment (E989) to soon release first results towards the target of a fourfold improvement over the Brookhaven E821 determination. In the near future, we also look forward to measurements from the methodologically independent experimental program at J-PARC (E34). To leverage the new experimental efforts, the theory errors must be reduced to the same level as the experimental uncertainties. The dominant sources of uncertainty in the SM prediction of the muon g-2 are from the hadronic corrections, in particular, from the hadronic vacuum polarization (HVP) and hadronic light-by-light scattering contributions. There are a number of complementary theoretical efforts underway to better understand and quantify these hadronic corrections, including dispersive methods, lattice QCD, and effective field theories, as well as a number of different experimental efforts to provide inputs to dispersive, data-driven evaluations. A concerted effort of the theory community to improve upon and scrutinize the existing SM results has been made possible thanks to the formation of the Muon g-2 Theory Initiative and a Whitepaper summarizing the current theory status has been recently finalized.

Matching the precision of the new experiments requires to determine the HVP contribution at the per-mille level. The goal of this workshop is to bring together theorists from the lattice QCD community to discuss, assess, and compare the status of the various efforts, and to map out strategies for obtaining the best theoretical predictions and for reaching a sub-percent precision.

The workshop extends the series of topical workshops by the Muon g-2 Theory Initiative, featuring a mix of talks and dedicated discussion sessions on specific topics.

Participants
  • Aaron Meyer
  • Aida El-Khadra
  • Alejandro Vaquero
  • Alessandro Conigli
  • Alex Keshavarzi
  • Alexander Nesterenko
  • Alexander Segner
  • Andreas Juettner
  • Andreas Kronfeld
  • Andreas Risch
  • Andrew Yong
  • Anthony Sebastian Francis
  • Antoine Gerardin
  • Antonin Portelli
  • Balint Toth
  • Ben Hörz
  • Benjamin Jaeger
  • Bhavna Yadav
  • Bigeng Wang
  • Bogdan Malaescu
  • Carleton DeTar
  • Christine Davies
  • Christoph Lehner
  • Christopher Aubin
  • Chulwoo Jung
  • Craig McNeile
  • Csaba Török
  • Curtis Peterson
  • Daniel Mohler
  • Daniel Simons
  • Davide Giusti
  • Elvira Gamiz
  • En-Hung Chao
  • Erik Gustafson
  • Finn Stokes
  • Gaurav Ray
  • Gen Wang
  • Georg von Hippel
  • Gilberto Colangelo
  • Hartmut Wittig
  • Harvey Meyer
  • Hwancheol Jeong
  • J Tobias Tsang
  • Jana N. Guenther
  • Jonna Koponen
  • Julian Parrino
  • Jérôme Charles
  • Kalman Szabo
  • Kehfei Liu
  • Kim Maltman
  • Kohtaroh Miura
  • Laurent Lellouch
  • Lee Roberts
  • Leonardo Giusti
  • Letizia Parato
  • Luchang Jin
  • Lucius Bushnaq
  • Lukas Varnhorst
  • Maarten Golterman
  • Marco Cè
  • Marina Krstic Marinkovic
  • Martin Hoferichter
  • Massimo Passera
  • Matteo Di Carlo
  • Mattia Bruno
  • Maxwell Hansen
  • Michael Peardon
  • Michel Davier
  • Michele Pepe
  • Miguel Teseo San José Pérez
  • Nico Battelli
  • Nikolai Husung
  • Nils Hermansson-Truedsson
  • Padmanath M
  • Peter Boyle
  • Peter Stoffer
  • Rainer Sommer
  • Rajnandini Mukherjee
  • santi Peris
  • Savvas Zafeiropoulos
  • Shaun Lahert
  • Shigemi Ohta
  • Silvano Simula
  • Simon Kuberski
  • Sophie Mutzel
  • Srijit Paul
  • Steven Gottlieb
  • Thomas Blum
  • Thomas Teubner
  • Tim Harris
  • Urs Wenger
  • Vera Guelpers
  • Willem Verplanke
  • Xiao-Ming Xu
  • Yannick Meurice
  • Zhiqing Philippe Zhang
  • Zoltan Fodor
    • 15:05 16:35
      Collaboration talks
    • 16:35 16:50
      Break 15m
    • 16:50 17:45
      Specific topic: Disconnected HVP

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Harvey Byron Meyer
      • 16:50
        Disconnected HVP 10m

        Session leader

        Speaker: Harvey Meyer (Johannes Gutenberg University Mainz)
      • 17:00
        Disconnected HVP from BMWc 5m
        Speaker: Balint Toth (University of Wuppertal)
    • 15:05 15:55
      Specific topic: Discretization effects and continuum extrapolation

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Ruth Van de Water (Brookhaven National Laboratory)
      • 15:05
        Discretization effects and continuum extrapolation 10m

        Session leader

        Speaker: Ruth Van de Water (Brookhaven National Laboratory)
      • 15:15
        Logarithmic corrections to $a^n$ behaviour 5m
        Speaker: Nikolai Andre Husung (Deutsches Elektronen-Synchrotron DESY)
      • 15:20
        Taste improvement in the HVP contribution to the muon g-2 5m
        Speaker: Laurent Lellouch (CNRS and Aix-Marseille U.)
    • 15:55 16:05
      Break 10m
    • 16:05 16:55
      Specific topic: Scale setting

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Kalman Szabo (Forschungszentrum Julich)
      • 16:05
        Scale setting 10m

        Session leader

        Speaker: Kalman Szabo (Forschungszentrum Julich)
      • 16:15
        High precision scale setting 5m
        Speaker: Lukas Varnhorst
      • 16:20
        M_\Omega scale setting with HISQ 5m
        Speaker: Aaron Meyer
      • 16:25
        w_0 scale setting from charmonium 5m
        Speaker: Daniel Hatton
    • 16:55 17:05
      Break 10m
    • 17:05 17:55
      Specific topic: QED + Isospin breaking

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Vera Guelpers (University of Edinburgh)
      • 17:05
        QED + Isospin breaking 10m

        Session leader

        Speaker: Vera Guelpers (University of Edinburgh)
      • 17:15
        HVP with C* boundary conditions 5m
        Speaker: Marina Krstic Marinkovic (LMU Munich)
      • 17:20
        Leading isospin breaking effects in the anomalous magnetic moment of the muon 5m
        Speaker: Andreas Risch (Universität Mainz)
    • 15:05 15:55
      Specific topic: Finite-size effects

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Maarten Golterman (San Francisco State University)
      • 15:05
        Finite-size effects 10m

        Session leader

        Speaker: Maarten Golterman (San Francisco State University)
      • 15:15
        The timelike pion form factor and finite-size corrections to the vector correlator 5m
        Speaker: Harvey Meyer (Johannes Gutenberg University Mainz)
      • 15:20
        Correcting finite-size effects in the HVP contribution to the muon g-2 using large-volume lattice QCD simulations 5m
        Speaker: Laurent Lellouch (CNRS and Aix-Marseille U.)
      • 15:25
        Finite-volume corrections to the vector correlator from space-like observables 5m
        Speaker: Maxwell Hansen (CERN)
      • 15:30
        FV effects in the EFT of a_mu^HVP 5m
        Speaker: santiago peris (Univ. Autonoma de Barcelona)
      • 15:35
        Finite-volume effects for the strong isospin-breaking contribution 5m
        Speaker: Christoph Lehner (University of Regensburg & BNL)
      • 15:40
        Electromagnetic finite-size effects on the two-pion contribution to the HVP 5m
        Speaker: Dr Antonin Portelli (The University of Edinburgh)
    • 15:55 16:05
      Break 10m
    • 16:05 16:55
      Specific topic: Long distance statistical errors

      Each session will be opened by a short introductory talk (10 min) and followed by a long discussion (40 min), enriched by optional 2/3-slide topical talks.

      Convener: Daniel Mohler (Helmholtz-Institut Mainz)
      • 16:05
        Long distance statistical errors 10m

        Session leader

        Speaker: Daniel Mohler (Helmholtz-Institut Mainz)
      • 16:15
        Gaining Statistics: DDHMC in the era of GPU nodes 5m
        Speaker: Peter Boyle
      • 16:20
        Two-pion contributions to the hadronic vacuum polarization with staggered quarks 5m
        Speaker: Mr Shaun Lahert
    • 16:55 17:05
      Break 10m
    • 17:05 18:05
      Crosschecks lattice

      Give some details about the observable

      Convener: Laurent Lellouch (CNRS and Aix-Marseille U.)
    • 15:05 16:25
      Comparison with e+e-/R-ratio data
      Convener: MARTIN HOFERICHTER (University of Washington)
      • 15:05
        Comparison with e+e-/R-ratio data 10m

        Session leader

        Speaker: Martin Hoferichter (University of Bern)
      • 15:15
        $e^+e^-$ data discrepancies in the context of the BMW result 5m
        Speaker: Michel Davier (LAL-Orsay, Universite Paris-Sud 11)
      • 15:20
        Muon g−2 and $\Delta \alpha$ connection 5m
        Speaker: Massimo Passera (INFN Padova)
      • 15:25
        Impact of correlations between $a_mu$ and alpha_QED on the EW fit 5m
        Speaker: Bogdan Malaescu (Centre National de la Recherche Scientifique (FR))
      • 15:30
        Constraints on the two-pion contribution to HVP 5m
        Speaker: Dr Peter Stoffer
      • 15:35
        Electroweak running couplings from the lattice 5m
        Speaker: Miguel Teseo San José Pérez (Johannes Gutenberg Universität)
      • 15:40
        Mainz/CLS Running Alpha and Electroweak Precision Science 5m
        Speaker: Kohtaroh Miura (Helmholtz-Institut Mainz)
    • 16:25 16:35
      Group photo 10m
    • 16:35 17:55
      Summary
      Convener: Hartmut Wittig
      • 16:35
        Continuum extrapolation of a_\mu^{I=0} 5m
        Speaker: Laurent Lellouch
      • 16:40
        Summary 1h 15m
        Speaker: Hartmut Wittig
    • 17:55 18:10
      Concluding remarks 15m