IRN Terascale @ IJCLab Orsay

Session

Beyond the Standard Model

20 avr. 2026, 14:20

Auditorium Pierre Lehmann (IJCLab)

2. Challenging Majorana Neutrino Effects in B→K(∗)νν and K→πνν Decays

Claire Chevallier (IJCLab - Université Paris Saclay)

20/04/2026 14:20

BSM

The $B\to K \nu \nu$ decays are among the cleanest rare processes in the Standard Model (SM), as they are dominated by short-distance contributions. Recently, the Belle-II experiment has observed this process for the first time, with a branching ratio that lies $\approx 3\sigma$ above its SM prediction. Such deviation can be consistently accommodated in an Effective Field Theory (EFT) scenario...

7. Reinterpretation of searches for supersymmetry in models with variable R-parity-violating coupling strength using the full ATLAS Run 2 Dataset

Lorenzo Feligioni (in2p3)

20/04/2026 14:40

BSM

This work reinterprets thirteen existing searches for supersymmetry (SUSY) conducted by the ATLAS Collaboration using the full Run 2 dataset from the Large Hadron Collider. Unlike traditional analyses that assume fixed R-parity scenarios, the study considers SUSY models with variable R-parity-violating (RPV) coupling strengths, allowing the lightest supersymmetric particle to exhibit either...

14. Prospects of Heavy Neutral Leptons via ALP portal at future LHC

Ana Martín-Galán (IFIC (CSIC-Univ. Valencia))

20/04/2026 15:00

BSM

Heavy neutral leptons (HNLs) and axion-like particles (ALPs) are both well-motivated candidates for beyond the Standard Model (BSM) physics. ALPs with couplings to gluons can be abundantly produced at the LHC. Therefore, HNLs produced via the ALP portal may provide unprecedented sensitivity to HNL parameters. In this talk, I will present the sensitivities of ATLAS and future far detectors to...

10. What is the 650 GeV resonance made of ?

Francois Richard (LAL/Orsay)

20/04/2026 15:20

BSM

Nine statistically significant decay channels are observed in LHC data around a mass of 650 GeV. We interpret three of them as coming from a narrow resonance observed in e+e-, 2 photons and ZZ which could be a J=2 Kaluza Klein graviton resonance called T690 (T for tensor with J=2). This hypothesis is reinforced by noting that this signal disappears in ZZ when treated as a scalar. Assuming a...

24. Observable gravitational waves from TeV-scale horizontal SU(2) phase transitions

Anna CHRYSOSTOMOU (LPTHE)

20/04/2026 16:15

BSM

We investigate a flavoured horizontal gauge extension of the Standard Model (SM), and demonstrate that first-order phase transitions (FOPTs) generically arise during its TeV-scale symmetry breaking. These FOPTs occur only for flavour gauge couplings $g_f \sim \mathcal{O}(1); beyond this, one-loop corrections to the quartic interaction start to dominate the thermal potential and weaken the...

23. Anomalies, Radiative Hierarchies and Dark Matter in Secluded U (1) Extensions

Arno Goudeau (LPTHE, Sorbonne University)

20/04/2026 16:35

BSM

U(1) extensions of the Standard Model have received significant attention.
However, concrete examples with anomalies in the effective low-energy
theory remain scarce.
We present a model with three main features. First, it includes a
hierarchy between fermions charged under the new U(1) and the new gauge
boson, leading to an apparent anomaly at low energies. Second, it provides
a viable...

19. Phenomenology of colour sextet baryons in composite Higgs models

Rosy Caliri (University of Würzburg)

20/04/2026 16:55

BSM

Composite Higgs theories with partial compositeness are gauge theories in which the Higgs boson arises as a pseudo Nambu Goldstone boson (pNGB), and top partners appear as bound states of three hyperfermions originating from a fermionic UV completion. These models offer a promising solution to the naturalness problem of the Higgs sector and predict additional pNGBs and vector-like baryons at...

13. Signatures of a Standard Model duality

Dr Giacomo Cacciapaglia (LPTHE)

20/04/2026 17:15

BSM

The Standard Model may emerge as the effective low energy limit of a simpler UV theory via gauge duality. I will discuss how a non-supersymmetric duality on QCD (akin to Seiberg dual in SQCD) can lead to a viable Standard Model. New low energy states are predicted, close to a supersymmetric spectrum, while flavour structures are cast into flavour-full Higgs fields. Potential signature software...