BSM at FCC-ee workshop

23 Sept 2026, 09:00 → 25 Sept 2026, 17:00 Europe/Zurich

CERN

Giacomo Polesello (INFN, Sezione di Pavia (IT)), Joe Davighi, Rebeca Gonzalez Suarez (Uppsala University (SE)), Sophie Alice Renner (University of Glasgow (GB))

This workshop, bringing together theorists and experimentalists, will cover the full scope of BSM physics at FCC-ee, including: 

• Direct discovery of light new physics (e.g. ALPs, dark photons, HNLs, dark sectors)
• Indirect discovery potential of precision measurements (e.g. Z pole, Higgs couplings, top precision, off Z pole)

The workshop will be held in-person at CERN, with the option to join remotely on zoom.

The day before, there is a related workshop on physics at FCC-hh, which is likely to be of interest to many participants.

Wednesday 23 September

09:20 → 12:20 Novel searches for long-lived or invisible particles

09:20 Intro

Speakers: Giacomo Polesello (INFN, Sezione di Pavia (IT)), Joe Davighi (University of Cambridge (GB)), Rebeca Gonzalez Suarez (Uppsala University (SE)), Sophie Alice Renner (University of Glasgow (GB))

09:30 Search for Charged LLPs at FCC-ee

Speaker: Soumyaa Vashishtha (Deutsches Elektronen-Synchrotron (DE))

09:50 Invisible B decays

Speaker: Ella Wood (University of Cambridge (GB))

10:10 ALLEGRO vertex reconstruction

Speakers: Jana Faltova (Charles University (CZ)), Jana Faltova (Charles University (CZ))

10:30 Invisible particles with charm

Speaker: Dominik Suelmann (Technische Universität Dortmund)

10:50 Coffee break

11:20 Higgs portal to a strongly interacting dark sector

Speakers: Emre Sitti (Universität Zürich), Emre Sitti

11:40 Signature-based searches for displaced decays at FCC-ee: status, detector requirements and wishlist

Speaker: Juliette Alimena (DESY)

12:00 LLPs - theory

Speaker: Giovanna Cottin (Pontificia Universidad Católica de Chile (CL))

12:20 → 14:00 Lunch break

14:00 → 17:00 Novel observables, signatures and cross-talk with other working groups

14:00 Higgs CP violation

Speakers: Jay Nesbitt, Jay Nesbitt (University of Glasgow (GB))

14:20 t channel DM models

Speaker: Nudžeim Selimović (INFN Padova)

14:40 Fractionally charged particles

Speakers: Seth Koren (University of Notre Dame), Seth Koren, Seth Koren

15:00 Brainstorming on new observables

Speaker: Joe Davighi (University of Cambridge (GB))

15:20 Coffee break

15:50 Flavour for BSM

Speakers: Gino Isidori (University of Zurich (CH)), Gino Isidori (Unknown), Gino Isidori (University of Zurich (CH))

16:20 Cross-talk - FCC-hh

Thursday 24 September

09:30 → 12:30 Scalars and dark photons

09:30 Real scalar singlet

Speaker: Simone Tentori (UCLouvain)

09:50 A Map of the $\kappa_V - \kappa_\lambda$ Parameter Space

Speaker: Olivia Simon

10:10 2 loop running

Speaker: Anders Eller Thomsen (University of Bern)

10:30 2HDMs with FOPTs

Speaker: Christoph Englert (The University of Manchester (GB))

10:50 Coffee break

11:20 Dark photon to electron

Speakers: Rohan Rajagopalan, Rohan Sudarshan Rajagopalan (Syracuse University (US))

11:40 Dark photon in Higgs decays

Speaker: Axel Gallen (Uppsala University (SE))

12:00 LLP searches at the FCCee using timing

Speaker: Yansong Huang (University of California Davis (US))

12:30 → 14:00 Lunch break

14:00 → 16:50 Heavy Neutral Leptons (HNLs)

14:00 HNL theory

Speakers: Marco Drewes (Universite Catholique de Louvain (UCL) (BE)), Marco Drewes, Marco Drewes (Ecole Polytechnique Federale de Lausanne (EPFL))

14:20 HNL experiment

Speaker: Giacomo Polesello (INFN, Sezione di Pavia (IT))

14:40 Semileptonic HNL decays in fullsim

Speaker: Andrea Pareti (Pavia University and INFN (IT))

15:00 LLP in muons

Speaker: Mahmoud AlThakeel (CERN)

15:20 Coffee break

15:50 HNL Discussion (tbc)

19:30 → 22:00 Informal social dinner (tbd)

Friday 25 September

09:30 → 12:00 Axion-like particles (ALPs)

09:30 ALPs intro + theory

Speaker: Sophie Alice Renner (University of Glasgow (GB))

09:50 ALPs beyond Z-pole

Speaker: Anna Patricia Przybyl (Deutsches Elektronen-Synchrotron (DE))

10:10 Higgs ALPs to 4 kaons

Speaker: Sarah Alshamaily (Karlsruhe Institute of Technology)

10:30 ALPS into Leptons

Speaker: Safa Naseem (New York University Abu Dhabi (AE))

10:50 Coffee break

11:20 ALPS via Dark Higgs

Speakers: Reza Jafari (University of Tehran (IR)), Reza Jafari (Institute for Research in Fundamental Sciences (IPM))

11:40 LFV alps

Speakers: Marco Ardu (CNRS, LUPM and Univ. Valencia), Marco Ardu

12:00 → 13:40 Lunch Break

13:40 → 15:50 Indirect tests - NOTE EARLIER START TIME

13:40 Top-quark pair production sensitivity to heavy new physics at the FCC-ee

Speaker: Jacopo De Piccoli (Universita e INFN, Padova (IT))

14:00 Precision on and off Z pole

Speaker: Alessandro Valenti (University of Basel)

14:20 TBC

Speaker: Lukas Allwicher

14:40 How large can lepton mixing be?

Speaker: CHIARA GIULIANO - (Universidad de Granada)

15:00 Electroweak precision tests for asymptotic grand unification models

Speaker: Christian Verollet (IP2I Lyon)

15:20 Coffee Break