8th Plenary workshop of the Muon g-2 Theory Initiative 2025

Sep 8, 2025, 8:30 AM → Sep 12, 2025, 5:00 PM Europe/Paris

200/0- Auditorium P. Lehmann (IJCLab)

The Eighth Plenary Workshop of the Muon g-2 Theory Initiative, jointly organised by CPT, IJCLab and LPNHE, will be held at IJCLab from 8th to 12th of September 2025. The anomalous magnetic moment of the Muon (Muon g-2) has been receiving great attention, particularly in light of the final result from Fermilab’s E989 experiment and of the intense theoretical effort to match its precision, as well as new forthcoming precision measurements of the dominant two-pion channel. The workshop aims at discussing recent progress on these developments and future prospects.

 

Important deadlines:

Abstract submission: June 30

Early registration : June 30

Late registration : July 25

 

 

 

 

Affiche-8th-WS-Muons-theory-initiative-V3-4K.jpg

Affiche-8th-WS-Muons-theory-initiative-V3.jpg

IJCLab-map-A4-RectoVerso-web_010324 copie.pdf

parcours_RER_Orsay_Bures_Bat_200_IJCLab.pdf

Mon, September 8

Registration with coffee

1 Welcome speech by director Achille Stocchi & introduction (slides) from organizers

Informations.pdf

g-2 measurements

Convener: Thomas Teubner

2 Fermilab final result

Speaker: Alberto Lusiani

alusiani-gm2ti-orsay-sep25.pdf

3 Experiment update J-PARC

Speaker: Tsutomu Mibe

muong-2TI-Orsay-mibe-pub.pdf

10:30 AM Coffee break

Experimental inputs HVP

Convener: Toru Iijma

4 CMD2/3 (remote)

Speaker: Evgeny Solodov

Solodov_CMD_TI_2025_09.pdf

5 BABAR new pipi measurement

Speaker: Andres Pinto (LPNHE - CNRS)

g_2_workshop_AP.pdf

6 KLOE

Speaker: Lorenzo Cotrozzi

Cotrozzi_KLOE_8g-2TI.pdf

7 BESIII

Speaker: Weiping Wang

Muon_g-2_Orsay_wangwp_20250908.pdf

1:00 PM Lunch

8 SND (remote)

Speaker: Andrey Kupich

talk_SND.pdf

9 Belle II

Speaker: Qingyuan Liu

20250908_BelleII_ee2pipi_qyliu.pdf

HVP discussion

Convener: Achim Denig

Discussion_HVPdisp.pdf

4:15 PM Coffee break

Tau decays

Convener: Kim Maltman

10 Tau decays at Belle II and super tau-charm factory

Speaker: Changzheng Yuan

Yuan_tau_to_pipi_BelleII.pdf

11 Recent DMZ update

Speaker: Zhiqing Zhang (IJCLab)

tau-DMZ-250908.pdf

12 Bern group update

Speaker: Simon Holz

simon_holz_tauIB_bernupdate.pdf

13 RBC/UKQCD update

Speaker: Mattia Bruno

orsay25_bruno.pdf

Posters

14 Measurement of the transition form factor of the f_1(1285) in a partial wave analysis of gamma*gamma -> f_1(1285) at BESIII

Speaker: Jan Muskalla

Poster_Muskalla.pdf

15 A model for light tensor meson transition form factors

Speaker: Eirini Lymperiadou

MSc_posterFinal.pdf

16 Combination of 2pi and 4pi spectra from tau decays and application in a^HVP_mu

Speaker: Lucas Mansur

LMM_g2Workshop_2025.PDF

17 Scattering Amplitudes for massless QED processes at N^3LO using tensor decomposition

Speaker: Thomas Dave

Theory Initiative Poster- Thomas Dave.pdf

18 The pion vector form factor with inelasticities

Speaker: Leon Heuser

CoupledChannelVFF_LeonHeuser.pdf

19 The Muon Magnetic Moment and Physics Beyond the Standard Model

Speaker: Kilian Möhling

poster-Moehling.pdf

20 Error Scaling of Sea Quark Isospin-Breaking Effects

Speaker: Alessandro Cotellucci

Poster_Cotellucci.pdf

21 Description of three-body decays using Khuri-Treiman formalism

Speaker: Miriam Penners

Poster_Penners.pdf

22 The dependence of amu^HVP on the muon mass and how we can use it to reduce noise in lattice computation

Speaker: Leo Filipovic

Poster_Muonmassfits_final.pdf

23 Improved pseudoscalar transition form factors in Resonance Chiral Theory and their g – 2 contributions

Speaker: Emilio Estrada

P-TFF in Resonance Chiral Theory.pdf

Reception (cocktail dinner)

Tue, September 9

Tau decays

Convener: Kim Maltman

24 FSR and rho-width IB corrections beyond scalar QED and their impact on muon g-2

Speaker: Genaro Toledo

Toledo_widthdiff.pdf

Tau IB corrections discussion

Convener: Maarten Golterman

IB-discussion.pdf

10:00 AM Coffee break

MC, radiative corrections

Convener: Fedor Ignatov

25 Dispersive analysis of the isospin-breaking corrections to pipi scattering and pion vector form factor

Speaker: Martina Cottini

pipi_MCottini.pdf

26 RadioMonteCarLow 2 overview

Speaker: Marco Rocco

mr-ti8.pdf

27 McMule update

Speaker: Sophie Kollatzsch

kollatzsch-8TI.pdf

28 Babayaga@NLO

Speaker: Fulvio Piccinini

piccinini.pdf

29 Fast evaluation of Feynman integrals for Monte Carlo generators

Speaker: Pau Petit Rosas

PhokharaTheoryInititative.pdf

MC generators and radiative corrections discussion

Convener: Yannick Ulrich

MC discussion.pdf

1:00 PM lunch (Building (Bât.) 230)

Disp HVP

Convener: Bastian Kubis

30 DHMZ

Speaker: Bogdan MALAESCU (LPNHE, IN2P3, CNRS)

amuHVP_Malaescu.pdf

31 KNTW

Speaker: Aidan Wright

A_Wright_Muon_g_2_Theory_Initiative_2025_Presentation_Opt_1 (12).pdf

32 Dispersive approach

Speaker: Thomas Leplumey

vff_orsay_2509.pdf

4:00 PM Coffee break

33 pQCD inclusive (remote)

Speaker: Diogo Boito

Boito-Ruds-pQCD-g-2-TI-Orsay.pdf

34 The pion vector form factor with explicit inelasticities

Speaker: George Chanturia

Pion_VFF_with_explicit_inelasticities.pdf

Disp HVP discussion

Convener: Gilberto Colangelo

Orsay25-HVP-discussion.pdf

Wed, September 10

Lattice HVP: part 1

Convener: Letizia Parato

35 BMW

Speaker: Finn Stokes

finnstokes-bmw-gm2ti2025.pdf

36 ETM

Speaker: Antonio Evangelista

talkOrsay_AE.pdf

37 Aubin et al.

Speaker: Maarten Golterman

taste-breaking.pdf

10:15 AM Coffee break

Lattice HVP: part 2

Convener: Davide Giusti

38 FNAL/HPQCD/MILC

Speaker: Jacob Sitison

Sitison_HVP_from_Fermilab_HPQCD_MILC.pdf

39 Mainz

Speakers: Alessandro Conigli, Simon Kuberski

25orsay_mainz_hvp.pdf

40 RBC/UKQCD

Speakers: Christoph Lehner, Julian Parrino

RBC_UKQCD_HVP_Talk_Parrino.pdf

41 RC*

Speaker: Paola Tavella

G_2_talk_25.pdf

1:00 PM Lunch (Building (Bât.) 230)

SC members meeting

Convener: Aida El-Khadra

Lattice HVP discussion

Conveners: Marina Marinkovic, Steven Gottlieb

42 EM corrections to HVP: lattice QCD vs. data-driven evaluations

Speaker: Volodymyr Biloshytskyi

Biloshytskyi_Orsay2.pdf

43 IB with CCS

Speaker: Dominik Erb

IB_with_CCS_Erb.pdf

44 LD QED (RBC)

Speakers: Christoph Lehner, Julian Parrino

qed-ld.pdf

45 Discussion

Speakers: Marina Krstic Marinkovic (ETH Zurich), Steven Gottlieb (Indiana University)

WednesdayLatticeHVPdisc_v2.pdf

4:00 PM Coffee break

Connections

Convener: Carleton DeTar

46 R-ratio (ChiQCD)

Speaker: Jian Liang

R_and_HVP_2509.pdf

47 NLO HVP (Mainz)

Speaker: Arnau Beltran

NLOHVP_Mainz.pdf

Thu, September 11

Lattice HLbL

Convener: Urs Wenger

48 RBC/UKQCD

Speaker: Thomas Blum

talk.pdf

49 ETM

Speaker: Simone Romiti

Romiti-Orsay.pdf

50 BMW

Speaker: Antoine Gérardin

Orsay1.pdf

51 Sign of the disconnected contribution to the pion TFF : Mainz update

Speaker: Antoine Gérardin

Orsay2.pdf

Lattice HLbL discussion

Convener: Christoph Lehner

hlbl-questions.pdf

10:40 AM Coffee break

Experimental inputs HLbL

Convener: Johan Bijnens

52 BESIII

Speaker: Christoph Redmer

CFR250911.pdf

53 Belle II plan

Speaker: Hisaki Hayashii

piTFF.-g-2WS-Orsay-250910.pdf

54 New high-precision transition form factor measurement of the pi0 at A2/MAMI

Speaker: Achim Denig

Muon_g-2_TheoryInitiative_Denig_pdf.pdf

Disp HLbL: Part 1

Convener: Christoph Redmer

55 Dispersive approach to HLbL in four-point kinematics

Speaker: Maximilian Zillinger

orsaypresentation.pdf

1:00 PM Lunch

56 Dispersive approach in triangle kinematics

Speaker: Emilis Kaziukenas

Triangle_Paris_SEP2025.pdf

57 Update on hQCD

Speaker: Jonas Mager

Orsay2025_JonasMager.pdf

3:30 PM Coffee break

Short visit to Museum d'Orsay in Paris

Make sure to be 30' in advance for entering the museum. The first group slots at 18:00, the last one at 18:15.

Dinner in Museum d'Orsay

Fri, September 12

Disp HLbL: Part 2

Convener: Anton Rebhan

58 Short-distance constraints

Speaker: Johan Bijnens

paris25.pdf

59 S-wave rescattering + two-photon MC

Speaker: Igor Danilkin (Johannes Gutenberg University of Mainz)

Danilkin2025_Orsay.pdf

60 Tensor/axials

Speaker: Hannah Schäfer

HannahSchaefer_SlidesOrsay.pdf

10:30 AM Coffee break

Disp HLbL discussion

Convener: Peter Stoffer

61 Tensor meson pole contributions

Speaker: Emilio Estrada

Tensor Meson Pole Contributions within RchiT.pdf

62 Update on HLbL in soft kinematics

Speaker: Jan-Niklas Toelstede

SoftKinematicsUpdate.pdf

63 Discussions (tensor TTFs, towards more detailed comparison of lattice and data-driven evaluation; HLbL lattice overflow)

Discussion-HLbL.pdf

MUonE

Convener: Peter Stoffer

64 MUonE

Speaker: Riccardo Pilato

MUonE_TheoryInitiative25_RP.pdf

1:00 PM Lunch (Building (Bât.) 230)

65 Future plans: the next steps for the Theory Initiative

Speaker: Aida El-Khadra

Final_Day_Orsay2025.pdf

4:00 PM Coffee