Symmetry and Topology in Particle Physics

9 mars 2026, 09:00 → 12 mars 2026, 17:20 Europe/Paris

Centre de conférences Marilyn et James Simons (Le Bois-Marie)

Symmetry and Topology in Particle Physics    
March 9-12, 2026    
at IHES - Marilyn and James Simons Conference Center    
How to get to IHES

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In the past decade, sweeping progress in our understanding of quantum field theory (QFT) has revealed new organizing principles whose impact is already being felt across high energy, condensed matter, and mathematical physics. These include the generalization of the conventional principle of symmetries to include those that act on extended objects and/or do not come with an inverse. The goal of this workshop is to bring these new theoretical developments to bear on the problems of particle physics. The workshop aims to establish a new bridge between the formal and phenomenological high-energy physics communities, which will drive progress in both directions. 

 

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Organizers:

Lea Bottini (IHES), Julio Parra Martinez (IHES), Alessandro Podo (IHES), Giovanni Rizi (IHES)

Scientific Committee:

Nathaniel Craig (UCSB), Clement Delcamp (IHES), Henriette Elvang (Michigan), LianTao Wang (Chicago)

Invited speakers:

• Daniel Brennan (University of Birmingham)
• Yichul Choi (Institute for Advanced Study)
• Clay Córdova (University of Chicago)
• Lucia Córdova (CERN)
• Nathaniel Craig (UC Santa Barbara)
• Raffaele Tito D’Agnolo (IPhT, CEA Saclay/ENS)
• Isabel García García (University of Washington)
• Ben Gripaios (Cambridge University)
• Diego García-Sepúlveda (Harvard University)
• Sungwoo Hong (KAIST)
• Po-Shen Hsin (King's College London)
• Seth Koren (University of Notre Dame)
• Ho-Tat Lam (Stanford University) REMOTE TALK
• Vazha Loladze (Oxford University)
• Mario Reig (CERN)
• Ling-Xiao Xu (ICTP)

 

S&T26_Poster.pdf

lun. 9 mars

09:00 → 09:30 Registration and welcome coffee

09:30 → 10:30 TBA

Orateur: Clay Córdova (University of Chicago)

10:30 → 11:00 Coffee break

11:00 → 12:30 Discussion: "Monopoles, Strings, etc."

Orateurs: Daniel Brennan (University of Birmingham), Sungwoo Hong (KAIST)

12:30 → 14:00 Lunch

14:00 → 15:00 Free discussion

15:00 → 15:30 Coffee break

15:30 → 16:30 Abelian Instantons in Quantum Field Theory and Gravity

Orateur: Isabel García García (University of Washington)

mar. 10 mars

09:00 → 09:30 Welcome coffee

09:30 → 10:30 2d Dualities and Mass Hierarchies

I will explore the Kramers-Wannier duality in the continuum and comment on its implications for the electroweak hierarchy problem.

Orateur: Raffaele Tito D'Agnolo (IPhT, CEA Saclay/ENS)

10:30 → 11:00 Coffee break

11:00 → 12:30 Discussion "Generalized Symmetries: Useful for Model Building?"

Orateurs: Nathaniel Craig (UC Santa Barbara), Ben Gripaios (Cambridge University)

12:30 → 14:00 Lunch

14:00 → 15:00 Dynamics of the Fermion-Rotor System

In this talk, I will examine the dynamics of the fermion–rotor system, originally introduced by Polchinski as a toy model for monopole–fermion scattering. Despite its simplicity, the system is surprisingly subtle, with ingoing and outgoing fermion fields carrying different quantum numbers. I will show that the rotor acts as a twist operator in the low-energy theory, changing the quantum numbers of excitations that have previously passed through the origin to ensure scattering consistent with all symmetries, thereby resolving the long-standing Unitarity puzzle. I will then discuss generalizations of this setup with multiple rotors and unequal charges, and demonstrate how the system can be viewed as a UV-completion of boundary states for chiral theories, establishing a connection to the boundary conformal field theory based proposal for resolving the puzzle.

Orateur: Vazha Loladze (University of Oxford)

15:00 → 15:30 Coffee break

15:30 → 16:30 Free discussion

16:30 → 17:30 QCD Wilson Lines in IR Chiral Lagrangian (Remote)

In this talk, we will answer the question: What does a QCD Wilson line flow to in the IR chiral Lagrangian? We will first present a symmetry-based argument showing that the Wilson line is not completely screened in the IR. We then propose a disorder operator realization of the Wilson line in the chiral Lagrangian. This allows us to model heavy-light mesons and baryons and describe the dissolution of confining strings into pions within the chiral Lagrangian.

Orateur: Ho Tat Lam (Stanford University)

mer. 11 mars

09:00 → 09:30 Welcome coffee

09:30 → 10:30 Spurion Analysis for a Class of Selection Rules Without Group Actions

Recent advances have uncovered a new class of selection rules in particle physics models arising from non-invertible fusion algebras. We refer to these as non-invertible selection rules (NISRs), distinguishing them from conventional selection rules derived from ordinary group laws. In this talk, we illustrate their implications in perturbation theory using spurion analysis, and connect to aspects of "loop-induced groupification" and particle decoupling in effective field theories. The discussion is based on arXiv 2510.18972, 2508.14970, 2503.19964.

Orateur: Ling-Xiao Xu (ICTP)

10:30 → 11:00 Coffee break

11:00 → 12:30 Discussion: "The S-Matrix, Generalized"

Orateurs: Lucia Córdova (CERN), Diego García-Sepúlveda (Harvard University)

12:30 → 14:00 Lunch

14:00 → 15:00 Free discussion

15:00 → 15:30 Coffee break

15:30 → 16:30 Student talks

Orateurs: Finn Gagliano (Durham University), Jonah Berean-Dutcher (UBC & IHES), Marius Kongsore (NYU)

jeu. 12 mars

09:00 → 09:30 Welcome coffee

09:30 → 10:30 Berry Phase on Boundary Conformal Manifolds

Conformal boundary conditions appear in various different contexts, in the study of impurities, scattering of massless particles off a heavy monopole, D-branes, and so on. I will discuss a new “higher” geometric structure the space of conformal boundary conditions possesses in 1+1d conformal field theories.

Orateur: Yichul Choi (Institute for Advanced Study)

10:30 → 11:00 Coffee break

11:00 → 12:30 Discussion: "The Global SM & Beyond"

Orateurs: Po-Shen Hsin (King's College London), Seth Koren (University of Notre Dame)

12:30 → 14:00 Lunch

14:00 → 15:00 Testing Stringy and Field Theory GUTs With Axions

The topological nature of axion couplings to gauge bosons offers unique opportunities to obtain information about the UV limit of the SM. The coupling to photons is particularly important experimentally. I will discuss why the discovery of an axion-like particle above the QCD line would rule out grand unified theories, the perturbative heterotic string, and F-theory GUTs. Based on 2206.07053, 2410.03820 and 2509.08042.

Orateur: Mario Reig (CERN)

15:00 → 15:30 Coffee break

15:30 → 16:30 Free discussion