LIO International Conference on "Asymptotic safety in Quantum Field Theory: Grand Unification"

5 juin 2024, 09:00 → 7 juin 2024, 17:00 Europe/Paris

web/Amphi Dirac (IP2I)

Aldo Deandrea (IP2I - Université Lyon 1), Giacomo Cacciapaglia (IP2I Lyon)

The LIO international conference on "Asymptotic safety in Quantum Field Theory: Grand Unification" aims at discussing the new recent results in particle physics and cosmology to explore new and emerging models of physics beyond the standard model. 

The conference will be in hybrid format, webcast and in-person event at the IP2I of Lyon, France. It is aimed at discussing and starting new collaborations and projects, so ample time will be left for discussion and collaborative work.
There is no registration fee.

The zoom link for those not joining in person will be shared by email to the participants few hours before the start of the conference.

Key speakers include:

Borut Bajc

Luc Darmé

Daniel Litim

Kamila Kowalska

Florian Nortier

Francesco Sannino (remote)

Enrico Sessolo

 

How to reach Lyon: if you fly in the Lyon Exupery airport, you can easily reach Lyon by taking the express tram Rhonexpress to the central Lyon Part-Dieu train station.

How to reach the IP2I : the tram T1 or T4 are not working due to maintenance.

See Tram maintenance work

There are substitution buses to Universite Lyon 1. From there you can walk to the IP2I: follow the tram track and turn on the first road on the left. The IP2I is down the road (click on the link below to see a map). Address: 4 rue Fermi, Villeurbanne.

View Map IP2I

 

The conference dinner will be on June 6th at 19h30 at the Bistrot du Palais

You can find here the location of Bistro du Palais

 

Scientific committee : G. Cacciapaglia (IP2I) and A. Deandrea (IP2I)

 

 

mer. 5 juin

1 Welcome and introduction

2 Phenomenology with trans-Planckian asymptotic safety

I will discuss some of the phenomenological aspects of embedding the Standard Model and/or models of New Physics in the framework of trans-Planckian asymptotic safety. In this setting, the presence of an interactive UV fixed point in the renormalization group flow of the gauge and Yukawa couplings imposes boundary conditions at the Planck scale. In the case of New Physics models, the ensuing fixed-point analysis leads to specific predictions for the IR phenomenology. This heuristic approach relies on simplifying approximations, including the computation of renormalization group equations at 1-loop, an arbitrary definition of the position of the Planck scale, and instantaneous decoupling of gravity. I will discuss how robust the predictions from asymptotic safety are if the assumptions listed above are relaxed.

Orateur: Kamila Kowalska

2024.06.05_Lyon_v2.pdf

10:30 Coffee break

3 Naturally small neutrino mass from asymptotic safety

I will discuss the possibility of dynamically generating arbitrarily small Yukawa couplings in the framework of trans-Planckian asymptotic safety. This effective mechanism may provide an interesting alternative to other dynamical means to generate small neutrino masses, e.g., the see-saw mechanism, and can be applied to various new physics scenarios requiring feeble Yukawa interactions (freeze-in dark matter, etc). I will show that this mechanism can be consistent with first-principle calculations in quantum gravity using the functional renormalization group. Finally, I will discuss possible gravitational-wave signals arising from the connection between these extreme UV and IR sectors.

Orateur: Enrico Sessolo

Sessolo_Lyon_2024.pdf

12:00 Lunch break

4 (Remote) On the many natures of the Higgs: From Composite Higgs Dynamics to the Standard Model as Magnetic Theory

Orateur: Francesco Sannino

5 UV-Completion Beyond Asymptotic Safety: Vainshtein Screening, UV/IR Mixing & Electroweak Naturalness

If one could probe sub-Planckian length scales by a hard (UV) scattering experiment, one would expect to end up with an extended semi-classical state (black hole) that decays into many soft (IR) quanta by Hawking radiation. This UV/IR mixing in gravity (dubbed classicalization) is a deeply nonlocal phenomenon. It suggests a path towards UV-completion by UV-obstruction, different from the traditional Wilsonian UV-fixed point (asymptotic safety). If the Standard Model is extended by specific self-sourced operators, the electroweak scale could also be stabilized against new large scales via Vainshtein screening that requires a little hierarchy. In this talk, I will discuss that implementing a ghost-free nonlocal Higgs mechanism leads to classicalization of the Higgs field, suggesting that fuzzy interactions trigger classicalization. References: arXiv:1010.1415, arXiv:2307.11741, arXiv:2311.08311

Orateur: Dr Florian NORTIER (CNRS/IN2P3 - IP2I Lyon)

Slides LIO 2024.pdf

16:00 Cofee break

jeu. 6 juin

6 Dualities in the UV

Orateur: Borut Bajc

lyon24-bajc.pdf

10:30 Coffee break

7 Asymptotic Grand Unification in 5 dimensions

Orateur: Giacomo Cacciapaglia (IP2I Lyon)

Cacciapaglia_LIO.pdf

12:00 Lunch break

8 Orbifold Stability of Asymptotic GUTs

Orateur: Anca Preda

LIO_Presentation_Anca.pdf

9 Directions for Model Building beyond Asymptotic Freedom

It is widely appreciated that the Standard Model is incomplete. Yet, and despite of significant experimental efforts, clear-cut signatures for new physics are unavailable. Also, theory guidance beyond the paradigms of asymptotic freedom or effective theories is scarce.

In this talk, I discuss top-down and bottom-up directions for model building. From a bottom-up perspective, it is proposed to turn the quest for vacuum stability into a primary model building task. The rationale for this is that while the onset of the SM instability around $10^{11}$ GeV is a high energy effect, a solution may arise from any scale below the Planck scale. Using the renormalisation group, I explain perturbative
mechanisms for stability and sketch out the landscape of Planck-safe models. From a top-down angle, prospects for asymptotically safe UV completions of the SM are discussed. Concrete model building results and challenges are highlighted in the context of supersymmetry and UV-safe extensions of the MSSM.

Orateur: Daniel Litim (University of Sussex)

2024-Litim-Lyon.pdf

16:00 Coffee break

19:30 Diner au bistrot du Palais

ven. 7 juin

10 Musings on horizontal gauge symmetries

Orateur: Luc Darme

LIO2024_DARME_vpdf.pdf

10:30 Coffee break

11 Interplay of chiral transitions in the standard model

We investigate nonperturbative aspects of the interplay of chiral transitions in the standard model in the course of the renormalization flow. We focus on the chiral symmetry breaking mechanisms provided by the QCD and the electroweak sectors, the latter of which we model by a Higgs-top-bottom Yukawa theory. The interplay becomes quantitatively accessible by accounting for the fluctuation-induced mixing of the electroweak Higgs field with the mesonic composite fields of QCD. In fact, our approach uses dynamical bosonization and treats these scalar fields on the same footing. In the first project we look at the changed infrared behaviour of the theory under inclusion of the QCD sector, compared to the pure Higgs-top-bottom model, with a focus on studying the naturalness problem in the model. In the current project we investigate UV completions within the Higgs-QCD model, a first analysis shows the existence of CEL-like scaling solutions.

Orateur: Richard Schmieden

SchmiedenLyon24.pdf

12:00 Lunch break

12 Safety, Criticality and Large N

I will discuss new RG relations obtained from studying the critical exponent in d dimension. As an example, I will apply those results to the Large Nf paradigm before discussing higher order corrections.

Orateur: Shahram Vatani (GGI Firenze)

LIOW.pdf

16:00 Coffee break