Introduction

• Sukanya Sinha (The University of Manchester (GB))

Flavoured resonances as motivation for third-generation searches

• Maximilian Amerl (Michigan State University (US))

Flavour-inclusive dijet searches are the leading constraints on leptophobic vector mediators whose couplings are taken to be universal across quark generations. That universality is an assumption. Relaxing it, by enhancing the coupling to third-generation quarks relative to the first two, is well motivated and, since Run 2, work by several theory groups has explored some scenarios quantitatively. The DM WG does not yet have a recommendation that would provide for a common ATLAS and CMS benchmark in these scenarios. This contribution presents a pathway to define benchmarks and visualise constraints on such models.

Inert Doublet Model [POSTPONED]

• Tania Robens (Rudjer Boskovic Institute (HR))

I am discussing a model that so far has only in one specific search by CMS. I also discuss why just recasting previous searches with the same final state will not help to exclude or discover this model.

Freeze-in at all couplings at the LHC

• Thomas REGGIO (LPCA)

The LHC phenomenology of frozen-in dark matter models is typically associated with searches for long-lived particles (LLPs). This is due to the fact that, in the simplest incarnations of freeze-in, dark matter only interacts feebly with the visible sector. However, feeble couplings are not a prerequisite for successful freeze-in. In this talk I will discuss examples of freeze-in with large couplings which can be probed at the LHC through a combination of LLP and prompt searches and highlight that, at the end of the day, many LHC dark matter searches probe combinations of microscopic models and cosmological histories.

DarkMatterLive: A Live Framework for Unifying Constraints on Dark Matter and Dark Sector Physics

• Brij Kishor Jashal (Rutherford Appleton Laboratory)

Dark matter searches now span a wide range of experimental and observational programmes, from collider and fixed-target experiments to direct detection, indirect searches, and cosmological probes. Yet the resulting constraints are often presented in different variables, conventions, and model assumptions, making it difficult to compare them consistently or to build coherent global pictures of viable dark matter and dark sector parameter space. This challenge is especially relevant in cross-field settings, where particle-physics limits, cosmological bounds, and astrophysical constraints must be interpreted side by side. DarkMatterLive is a collaborative platform designed to address this problem by building and sharing interactive visualisations of dark matter and dark sector constraints in a common, model-aware framework. Based on published experimental and observational results, it brings together limits that are otherwise difficult to compare and, where possible, recasts them into standard variables following widely used benchmark conventions. In this way, the platform helps connect results across particle physics, cosmology, and astrophysics while preserving clear links to the original sources, assumptions, and caveats. A representative use case is dark photon https://darkmatter.web.cern.ch/pages/BC1/main.html, where limits on kinetic mixing can be mapped into alternative parameter spaces and compared with complementary constraints from other probes. Hosted on CERN PaaS cloud infrastructure, DarkMatterLive is publicly available through https://darkmatter.web.cern.ch/ web interface, with benchmark plots online and a citable release archived as 10.5281/zenodo.18135859. The framework also interfaces naturally with community resources such as the HEPData portal, helping organise new inputs within a transparent review workflow. To support broad community use, DarkMatterLive provides a data-ingestion workflow based on CSV curve data and JSON metadata. New results and key reinterpretation and renormalisation factors are documented and peer-reviewed through GitHub pull requests or CERN GitLab merge requests before inclusion. Additional AI-MCP-based ingestion modules are being integrated into the platform workflows. DarkMatterLive is intended as an open tool for connecting particle, astrophysical, and cosmological perspectives on dark matter and dark sector physics, and for enabling more reproducible construction of global constraints across communities.

Developing new benchmarks for Run 3 and HL-LHC s-channel dark matter searches

• Maximilian Amerl (Michigan State University (US))

Simplified dark matter models are common interpretations in LHC searches for dark matter candidates and vector dark matter mediators. Existing searches can quickly be reinterpreted in the context of alternative models that feature similar mediators. We present a reinterpretation of an LHC dijet resonance search in the context of Hidden Abelian Higgs Models, which feature a dark photon mediator and an additional dark Higgs boson. This work is being continued in an effort to define new benchmarks for dark matter searches using Run 3 and HL-LHC data.

Probing mixed-state dark matter and flavor observables in a scalar-assisted baryonic gauge theory

• Taramati Guruwani (IIT Bhilai)

We explore a {standard model} extension based on a local $U(1)_B$ symmetry, where a baryon-charged scalar mediates interactions between a fermionic dark matter candidate and {standard model} quarks. In this setup, the dark matter relic abundance is shaped not only by standard annihilation channels but also by additional coannihilation processes induced by a new scalar. The presence of this mediator provides a unified link between {dark sector} and flavor physics, yielding distinctive phenomenological consequences. We conduct a detailed study of dark matter phenomenology, emphasizing the role of the mass splitting between the dark matter particles and the scalar mediator in determining the efficiency of coannihilation. The parameter space is examined in light of existing constraints from cosmological observations, direct and indirect detection experiments, as well as the collider searches at the {\text{LHC}}. Our analysis shows that the extended scalar sector opens up viable regions of parameter space beyond those accessible in minimal \(U(1)_B\) realizations, many of which are expected to be tested by forthcoming searches at {\text{XENONnT}} and {the \text{Cherenkov Telescope Array}}. Moreover, the model induces correlated signatures from flavor observables associated with the $b \to s $ transitions as well, serving as complementary tests of the underlying framework.

Photons, jets and missing momentum from a two-vector dark sector

• Yoxara Sánchez-Villamizar (LPTHE - CNRS - Sorbonne Université)

We investigate the LHC phenomenology of a vector dark-sector effective theory containing two neutral massive vector states, both odd under a dark-parity symmetry. The lightest state is stable and provides a dark-matter candidate, while the leading interactions with the Standard Model arise from dimension-six operators involving the hypercharge field strength. In the prompt-decay regime considered in this work, the heavier state can decay radiatively, leading to a $\gamma+\mathrm{jets}+E_T^{\mathrm{miss}}$ signature when the two dark vectors are produced in association with QCD radiation. We study this topology at the LHC through a cut-based analysis, comparing an inclusive missing-transverse-momentum selection with a three-bin strategy that retains coarse shape information. The binned analysis is found to substantially improve the expected reach and probes regions of the parameter space compatible with the observed relic abundance in the standard freeze-out scenario. We also discuss the freeze-in interpretation and the limitations associated with the effective field theory description at high masses.

Discussion