IRN Terascale @ IP2I Lyon

13 Nov 2024, 12:00 → 15 Nov 2024, 17:00 Europe/Paris

Amphi Dirac (IP2I Lyon)

Ana Margarida TEIXEIRA (LPC Clermont), Florian NORTIER (CNRS/IN2P3 - IP2I Lyon), Marie-Helene Genest (LPSC-Grenoble, CNRS/UGA (FR)), Nazila Mahmoudi (Lyon University), Nicolas Chanon (IP2I Lyon), Suzanne GASCON-SHOTKIN (IPN Lyon/Universite Claude Bernard Lyon 1)

We are looking forward to welcoming you for the fall meeting of the IRN Terascale in Lyon on 13-15 November 2024. 

On Wednesday 13 November, there will be a session dedicated to the preparation of the French contribution to the update of the European Strategy for Particle Physics (ESPPU) 2025, following the Zoom meeting on October 4th reviewing the highlights of the last update.  

Registration and abstract submission are now open. 

For any questions regarding the corresponding session, please contact the group conveners:

Higgs and EW	Iro Koletsou, Louis D'Eramo, Christophe Ochando, Pietro Slavich
BSM	Eric Chabert, Björn Herrmann, Romain Madar, Jérémie Quevillon
Dark Universe	Julien Masbou, Emmanuel Moulin, Kallia Petraki
Methods and Tools	Anja Butter, Mark Goodsell, Sabine Kraml

More information at terascale.in2p3.fr

Wednesday 13 November

12:15 Lunch

1 Welcome

2 In memoriam Ulrich Ellwanger

Speakers: Ana Margarida TEIXEIRA (LPC Clermont), Dr Cyril Hugonie (LUPM), Jean Orloff (LPC Clermont, Univ. Blaise Pascal)

U.Ellwanger-C.Hugonie.pptx

U.Ellwanger-J.Orloff.pptx

Welcome-UE-EPPSU-IP2I2024.pdf

Session on the European Strategy for Particle Physics Update 2025: ESPPU

Conveners: Ana Margarida TEIXEIRA (LPC Clermont), Fabrice Couderc (CEA/IRFU/SPP), Marie-Helene Genest (LPSC-Grenoble, CNRS/UGA (FR))

3 Introduction

Speaker: Laurent Vacavant (IN2P3)

Orga_ESPPU2025_IN2P3_20240918.pdf

4 Muon colliders

Speakers: Fabrice Balli (CEA Saclay), Fabrice Balli (CEA Saclay)

Mucoll_IRNTeraScale_WG1_20241113.pdf

5 ECFA summary

Speaker: Dirk ZERWAS (DMLab and IJCLab)

241113_ESPPU France.pdf

6 ECFA theory overview

Speaker: Margarete Muehlleitner (ITP Karlsruhe)

IRNTerascale.pdf

7 Perspectives on computing challenges

Speaker: Sabine Crépé-Renaudin (IN2P3)

ComputingforHEP_SCR_s.pdf

8 Sustainability issues

Speaker: Samuel Calvet (LPC)

2024_11_13_Terascale_ESPPU.pdf

9 Early career researcher ECFA summary

Speaker: Louis D'Eramo (LPCA - Clermont)

ECFA_ECR_Perspective.pdf

16:35 Meeting Photo on the front stairs, then Break

Session on the European Strategy for Particle Physics Update 2025

10 Discussion

Opening_EPPSU25_discussion.pdf

Thursday 14 November

Methods and Tools

11 MicrOMEGAs 6: new developments and physics applications

MicrOMEGAs is a computer program to compute different dark matter observables. In this talk we will present some new features of its latest release, version 6, and discuss some of their physics applications.

Speaker: Andreas Goudelis (LPC - Clermont Ferrand)

AndreasTerascale2024.pdf

12 SModelS v3: Going Beyond Z2 Topologies

SModelS is a public tool for fast reinterpretation of LHC searches for new physics based on a large database of simplified model results. While previous versions were limited to models with a Z2-type symmetry, version 3 can now handle arbitrary signal topologies. To this end, the tool was fully restructured and now relies on a graph-based description of simplified model topologies. In this talk, I will discuss the main conceptual changes and novel features of SModelS v3.

Speaker: Mohammad Mahdi Altakach

ALTAKACH_IRN_terascale_Lyon_2024.pdf

13 Hyperiso: A general BSM calculator for flavour observables

Hyperiso is a refactored and expanded version of the flavour code SuperIso allowing for efficient calculations of flavour observables. While SuperIso was dedicated to SM, THDM and several SUSY models, Hyperiso now implements a transparent interface with MARTY (a public tool to perform analytical QFT calculations) to extend SuperIso's observable calculation routines to generic BSM scenarii. In this talk, we will present the main structural changes and new features of the MARTY--Hyperiso pipeline.

Speakers: Niels FARDEAU, Théo REYMERMIER (IP2I Lyon + LPSC)

Terascale_24_11_14.pdf

14 Machine Learning the likelihoods

In recent years, the ATLAS collaboration has released full statistical models for some of their analyses, allowing for precise reinterpretation of experimental limits. These models incorporate numerous nuisance parameters and correlations between signal bins, but their complexity often results in prolonged computation times. This project seeks to develop a method for efficient yet accurate reinterpretation of experimental results in phenomenological studies. We are training Deep Neural Networks (DNNs) to act as surrogates for full statistical models by performing likelihood interpolation. This approach significantly reduces computation times, often by several orders of magnitude, while preserving a high level of accuracy.

In my talk, I will present the project and highlight recent progress, including the creation of a framework that uses Markov Chain Monte Carlo (MCMC) techniques to generate data, the training of Neural Networks to interpolate likelihoods, and the validation of these models on real-world analyses.The long-term objective is to develop a publicly accessible and maintainable database of trained machine learning models, which can be integrated into various reinterpretation tools, offering a valuable resource for the particle physics community.

Speaker: Rafal MASELEK (LPSC (Grenoble))

RMaselek.key

RMaselek.pdf

10:30 Break

Methods and Tools

15 Analyses surrogates and how to build them

I will present the reinterpretation of the CalRatio + X ATLAS analysis (arXiv:2407.09183), focusing on neutral long-lived particles decaying within the ATLAS hadronic calorimeter. The reinterpretation involves a Boosted Decision Tree (BDT) trained on truth-level variables to estimate the probability of events within the ABCD plane and assess the sensitivity of the analysis. The BDT weights, along with a Python code example, are available on HEPData to ensure reproducibility. Additionally, I will discuss how this method can be extended to other analyses, providing guidance for broader applications.

Speaker: Abdelhamid Haddad (LPCA)

IRN_Terascale: Analyses surrogates and how to build them .pdf

setup.sh

16 MadNIS

Theory predictions for the LHC require precise numerical phase-space integration and generation of unweighted events. We combine machine-learned multi-channel weights with a normalizing flow for importance sampling to improve classical methods for numerical integration. By integrating buffered training for potentially expensive integrands, VEGAS initialization, symmetry-aware channels, and stratified training, we elevate the performance in both efficiency and accuracy. Further, we show how differential programming techniques can boost the performance of current and planned MadGraph implementations. We empirically validate these enhancements through rigorous tests on diverse LHC processes.

Speaker: Theo Heimel (Heidelberg)

madnis_theo_heimel.pdf

BSM

17 Some non-axion solutions to the strong CP problem and their phenomenology

While axions (which are very well-motivated) heavily dominate the amount of work currently done regarding the strong CP problem, alternatives ought to be systematically investigated, in order to assess what the strong CP problem really entails (and potentially update our theoretical biases). In this context, I will talk about solutions that rely on spontaneously broken spacetime symmetries, and various UV structures, such as copies of the Standard Model's fields and interactions, or appropriately designed extended Higgs sectors. If time allows, I will talk about their collider, flavor and early universe phenomenology.

Speaker: Quentin BONNEFOY (Université de Strasbourg & IPHC, CNRS)

Bonnefoy_Terascale_IP2I.pdf

18 Leptophilic Z' at the FCC-ee

We present the detection prospects of new Standard Model (SM)-neutral vector bosons ($Z_{\prime}$) that couple exclusively to leptons at the Future Circular Collider in the electron-positron stage (FCC-ee). We focus our search on $Z’$ production with a radiated photon, and show that FCC-ee can significantly extend the unprobed parameter space for this class of models in the kinematically allowed mass range and outdo other proposed future lepton colliders. Furthermore, we look at the possibility of improving our bounds by studying the sensitivity dependence on detector parameters.

Speaker: Baibhab Pattnaik (IFIC (CSIC-University of Valencia) and LPC)

BaibhabLeptophilic_Z'_Terascale.pdf

12:30 Lunch

BSM

19 Quantum Tops: Quantum Information Meets High Energy Physics

The Standard Model of particle physics is a quantum field theory, based on quantum mechanics and special relativity. Therefore, it allows us to test fundamental properties of quantum mechanics. Top-quark pairs, which are generated at the LHC, are a unique high-energy system since their spin correlations can be measured. Thus, it is possible to study fundamental aspects of quantum mechanics such as entanglement and Bell non-locality using top-quark pairs, represented as two qubits. The environment provided by the LHC makes these studies especially attractive: the qubits are entangled through exotic interactions and are genuinely relativistic, at energies which are many orders of magnitude above conventional condensed-matter and optical experiments. In addition to the fundamental and interdisciplinary nature of these studies, quantum information observables can be used to develop new strategies to search for physics beyond the Standard Model. I will discuss the theoretical background, the first measurements of entanglement between top-quark pairs by the ATLAS and CMS collaborations, and the future prospect of the field.

Speaker: Yoav Afik (Enrico Fermi Institute, University of Chicago)

Quantum_Tops___IRN_Terascale_IP2I_Lyon.pdf

20 Search for Long Lived Particles at CMS

Depending on the length of the talk and the preference of the session conveners, the presentation could either focus on the search for heavy stable charged particles at CMS (work performed at IPHC) or cover a broader panel of LLP searches at CMS, associated to different experimental signatures in the detector.

Speaker: Caroline COLLARD (IPHC (Strasbourg))

IRN_nov2024_LLP_Collard.pdf

21 New LCSR B->K Form Factors determination

Deviations from the Standard Model have long been observed in semileptonic B-meson decays, notably $b→ s \ell \ell$ transitions, triggering speculations on potential New Physics effects in this sector. Following recent updates of $R_{K^{(*)}}$ and $BR(B_{(s)} → μμ)$, and the first measurement of $R_\phi$ by the LHCb collaboration, the sole remaining significant deviations from the SM in flavour-changing neutral currents B-decays now lie in the branching ratios of decays involving b → sμμ and in the angular observable P’5.

However, unlike $R_{K^{(*)}}$, $R_\phi$, and $BR(B_{(s)} → μμ)$, predicting $BR(B_{s}​→Mμμ)$ (with $M=K^{(∗)},ϕ,…$) is challenging due to significant non-perturbative QCD effects, which introduce up to 30% theoretical uncertainty—often comparable to experimental errors— hampering the potential of these observables for discovery

We undertake a new calculation of local $B→K$ form factors using Light-Cone Sum Rules, proposing an alternative method and reassessing the systematic error associated to semi-global quark-hadron duality. These form factor predictions are then used to compute relevant observables and perform fits of NP scenarios.

Speaker: Yann Monceaux (IP2I (Lyon))

GDR_MONCEAUX.pdf

22 First-order phase transitions from a broken horizontal SU(2) gauge symmetry

Under certain conditions, a first-order phase transition during early-universe symmetry breaking can generate observable signals in the stochastic gravitational-wave (GW) background. Since the Standard Model (SM) predicts a cross-over phase transition, detectable signals are expected to arise from beyond the SM frameworks, traditionally testable only at colliders. Motivated by this complementarity between collider experiments and GW observatories, we consider the breaking of a new non-abelian SU(2) gauge symmetry corresponding to a horizontal flavour gauge group embedded in the SM flavour structure. For such a model, the new gauge symmetry is broken far above the electroweak scale and constraints are dominated by “flavour-transfer” operators rather than flavour-changing currents. We calculate the finite-temperature corrections to the effective potential and determine the critical temperature for the phase transition. We compare two of the thermal resummation techniques favoured in the literature and examine the parameters for which the phase transition is strongly first-order.

Speaker: Anna CHRYSOSTOMOU (LPTHE)

Chrysostomou_IRN2024-Terascale_Lyon.pdf

23 In memoriam: Rohini Godbole

GenevieveBelanger_Terascale_Rohini.pdf

15:45 Break

Dark Universe

24 Latest Results from the XENONnT Dark Matter Experiment

Speaker: Ananthakrishnan RAVINDRAN

IRN_Ananthu_pdf.pdf

25 First axion and dark photon dark matter searches with MADMAX

Speaker: Vijay Dabhi (CPPM, Marseille)

MADMAX_IRN_2024.pdf

26 DarkSide-20k sensitivity to light dark matter particles

Speaker: Pascal PRALAVORIO (CPPM, Aix-Marseille Université, CNRS/IN2P3)

20241411_LowMass_Terascale.pdf

27 SMC meeting

28 Dîner au Café des fédérations

Institut de Physique des 2 Infinis de Lyon à Le Café Des Fédérations - Google Maps.pdf

Friday 15 November

Higgs and Electroweak

29 Introduction

Speakers: Christophe Ochando (LLR), Iro Koletsou (LAPP), Louis D'Eramo (LPCA - Clermont), Pietro Slavich (LPTHE Paris)

30 Studies of the energy dependence of diboson polarization fractions and the Radiation Amplitude Zero effect in WZ production with the ATLAS detector

Speaker: Joany Manjarres Ramos (L2I Toulouse, UT3, CNRS/IN2P3)

2024_Polarization_INR_Terascale.pdf

31 Heavy Higgs search in the 4l final state with CMS

Speaker: Mr Geliang Liu (Ecole polytechnique)

20241115_IRN_HeavyHZZ4l_GeliangLiu.pdf

10:15 Break

Higgs and Electroweak

32 HH searches at the HL-LHC in the bb𝝉𝝉 final state with ATLAS

Speakers: Minori FUJIMOTO (CPPM, Aix-Marseille Université, CNRS/IN2P3), Minori Fujimoto

IRNterascale_HH_bbtautau.pdf

33 Higgs physics opportunities at the FCC

Speaker: Giovanni Marchiori (APC Paris)

2024:11:15 - IRN Terascale - Higgs physics opportunities at the FCC.pdf

34 Linear Collider Facility - Introduction and Higgs programme below the ttbar threshold

The physics programme of linear e+e- colliders spans from the Z-Pole deep into the TeV range. Therefore, all Standard Model particles and their interactions are covered by the scientific programme of linear colliders. Beam polarisation allows for testing all aspects of the electroweak and the Higgs sector. New physics would lead to unique patterns of deviations from the Standard Model predictions. Examples are the set of couplings of Standard Model particles to the Higgs boson. At a centre of mass energy of 250 GeV coupling precisions of the order of 1% and better are achievable. This precision would confirm deviations from the standard model and allow for pinning down a concrete model. The contributions will show examples for these studies carried out in French groups.

Speaker: imad laktineh (in2p3-ucbl)

Strategy-ILCHiggs.pptx

35 Linear Collider Facility - Physics about ttbar threshold and outlook

At energies above 500 GeV processes such as di-Higgs production or associated top-Higgs production open up. Both processes will profit from the clean environment of e+e- collisions that will allow for a direct measurement of the Higgs self-coupling and an unambiguous determination of the CP properties of the Higgs boson.
The Higgs particle is intimately coupled to the top quark. Therefore, the full top programme can be considered as equally important to that of the Higgs. In the past years French groups made leading contributions to this topic. The top quark programme will cover a precise determination of the top quark mass as well as of the electroweak top quark couplings to the percent precision. Deviations from the Standard Model prediction would allow for interpretations in the frame of models with (warped) extra dimensions or (equivalent) models in which the Higgs and the top are composite. These measurements will be complemented by the determination of electroweak couplings of lighter Standard Model fermions in the per-mille range that in itself bears a considerable discovery potential. Finally, it will be also outlined how the energy reach of linear colliders is capable to complement discoveries that might be made in the upcoming HL-LHC phase.
The most mature proposal for a linear collider is the International Linear Collider ILC based on superconducting radio frequency (SCRF) cavities. Therefore, the physics potential will be mainly illustrated by recent results obtained in detailed simulation studies using the detector concepts ILD and SiD. These results are complemented by results obtained in studies for CLIC and where available for other linear collider variants. Recently, all variants are federated under the roof of the LCVision project that will allow for elaborating a coherent plan for the initial stage of a Linear Collider Facility and for the upgrades to higher energies.

Speaker: Roman Poeschl (LAL Orsay)

talk151124.odp

talk151124.pdf

36 Famous last words

IRN FLW Nov 2024.pdf

12:30 Lunch