In this work we illustrate a general framework to describe the LHC phenomenology of extended scalar (and fermion) sectors, with focus on dark matter (DM) physics, based on an effective field theory (EFT) with non-linearly realized electroweak symmetry. Generalizing Higgs EFT (HEFT), the setup allows to include a generic set of new scalar resonances, without the need to specify their UV origin, that could for example be at the interface of the Standard Model (SM) and the DM world. In particular, we study the case of fermionic DM interacting with the SM via two mediators, each of which can possess either CP property and originate from various electroweak representations in the UV theory. Besides trilinear interactions between the mediators and DM or SM pairs (including pairs of gauge field-strength tensors), the EFT contains all further gauge-invariant operators up to mass dimension $\textit{D}$ = 5. While remaining theoretically consistent, this setup offers enough flexibility to capture the phenomenology of many benchmark models used to interpret the results of experimental DM and BSM searches, such as two-Higgs doublet extensions of the SM or singlet extensions. Furthermore, the presence of two mediators with potentially sizable couplings allows to account for a broad variety of interesting collider signatures, as for example detectable mono-$\textit{h}$ and mono-$\textit{Z}$ signals. Correlations can be employed to diagnose the nature of the new particles.

Italy

Giorgio Arcadi

Spain

David Cabo-Almeida

Germany

Sven Fabian

Florian Goertz

Dark particles at the LHC: LHC-friendly dark matter characterization via non-linear EFT

We give a fresh look at the WIMP paradigm by considering updated limits and prospects for direct and indirect dark matter detection and covering realistic dark matter models, beyond the so-called simplified models, which have been the target of experimental scrutiny. In particular, we investigate dark matter scenarios featuring dwindled direct detection signals, due to loop or momentum suppression. Therefore, this review extends previous reviews in different aspects and motivates the search for WIMP dark matter in light of the present and near-future detectors.

United States

Maíra Dutra

India

Pradipta Ghosh

Manfred Lindner

France

Yann Mambrini

Brazil

Jacinto Neto

Mathias Pierre

Stefano Profumo

Chile

Farinaldo Queiroz

The waning of the WIMP: endgame?

We study freeze-in production of fermionic dark matter mediated by a <math altimg='si1.svg'><msup><mrow><mi>Z</mi></mrow><mrow><mo>&#8242;</mo></mrow></msup></math> gauge boson. In particular, we explore the regime of Boltzmann-suppressed production, when the Standard Model (SM) thermal bath temperature never exceeds the dark matter mass. The corresponding gauge coupling is then required to be significant, up to order one. As a result, this class of freeze-in models can be probed by the current and future direct dark matter detection experiments.

Finland

Oleg Lebedev

<italic>Z</italic>&#8242;-mediated dark matter freeze-in at stronger coupling

We discuss the possibility of interpreting the recent experimental hints in favor of a 95 GeV resonance with extensions of the Standard Model featuring an extra Higgs doublet and SM scalar (<math><mrow><mn>2</mn><mi>HDM</mi><mo>+</mo><mi>s</mi></mrow></math>) or pseudoscalar singlet (<math><mrow><mn>2</mn><mi>HDM</mi><mo>+</mo><mi>a</mi></mrow></math>). We compare the possibility of reproducing the experimental anomalies with the theoretical constraints on the extended Higgs sector as well as complementary bounds coming from flavor physics and other colliders searchers. For both the <math><mrow><mn>2</mn><mi>HDM</mi><mo>+</mo><mi>s</mi></mrow></math> and <math><mrow><mn>2</mn><mi>HDM</mi><mo>+</mo><mi>a</mi></mrow></math> we will consider a generic natural flavor conserving (NFC) model as well as the customary type-I, -II, -X and -Y configurations of the Yukawa coupling to the BSM Higgs bosons. We find that no model is able to reproduce all experimental hints, and plot the <math><mn>2</mn><mi>σ</mi></math> C.L. favored regions in the parameter space.

Australia

Giorgio Busoni

Navneet Krishnan

Is there a scalar or pseudoscalar at 95 GeV?

Abstract Recently, lattice formulations of Abelian chiral gauge theory in two dimensions have been devised on the basis of the Abelian bosonization. A salient feature of these 2D lattice formulations is that the gauge invariance is exactly preserved for anomaly-free theories and thus is completely free from the question of the gauge mode decoupling. In the present paper, we propose yet another lattice formulation sharing this desired property. A particularly unique point in our formulation is that the vertex operator of the dual scalar field, which carries the vector charge of the fermion and the “magnetic charge” in the bosonization, is represented by a “hole” excised from the lattice; this is the excision method formulated recently by Abe et al. in a somewhat different context.

Japan

Okuto Morikawa

Soma Onoda

Hiroshi Suzuki

Yet Another Lattice Formulation of 2D (1) Chiral Gauge Theory via Bosonization David Tong: lectures on gauge theory