Standard-Model (SM) hadronic parton showers initiated by secondary cosmic-ray production or dark matter (DM) annihilations robustly predict very low antinuclei yields and a strong additional suppression for heavier antinuclei. We show that an important exception can arise if DM annihilates into a confining dark sector that produces soft unclustered energy patterns (SUEPs). The hallmark of SUEPs is the emission of very large multiplicities of soft dark mesons (<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>π</mi><mi>D</mi></msub></math>), which can overcome the usual phase-space suppression of antinuclei formation in parton showers, provided that the dark mesons decay promptly into SM quarks, i.e., within a SM hadronization length. We study several benchmark realizations and find that for DM masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><mrow><mi>DM</mi></mrow></msub><mo>∼</mo><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>TeV</mi><mo stretchy="false">)</mo></math>, dark meson masses <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>m</mi><msub><mi>π</mi><mi>D</mi></msub></msub><mo>∼</mo><mn>400</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>π</mi><mi>D</mi></msub></math> dominantly decaying to <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi><mover accent="true"><mi>t</mi><mo stretchy="false">¯</mo></mover></math>, and a SUEP temperature <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>SUEP</mi></mrow></msub><mo>≃</mo><mn>0.1</mn><msub><mi>m</mi><mrow><mi>π</mi><mi>D</mi></mrow></msub></math>, DM annihilation into SUEPs can yield tens of antideuterons and a few antihelium-3 events at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="sans-serif">AMS-02</mi></math> at kinetic energies of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi mathvariant="script">O</mi><mo stretchy="false">(</mo><mi>GeV</mi><mo>/</mo><mi mathvariant="normal">n</mi><mo stretchy="false">)</mo></mrow></math> and a few antideuterons and antihelium-3 events in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="sans-serif">GAPS</mi></math> at energies below <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>0.5</mn><mtext> </mtext><mi>GeV</mi><mo>/</mo><mi mathvariant="normal">n</mi></mrow></math>. A future confirmation of an antinuclei signal by the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="sans-serif">AMS-02</mi></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="sans-serif">GAPS</mi></math> experiments could provide hints for hidden confining dynamics and would significantly constrain the relevant SUEP parameters.

Italy

Mattia Di Mauro

Canada

United States

Caleb Gemmell

Austin Batz

David Curtin

Fiorenza Donato

Nicolao Fornengo

CERN

Graham D. Kribs

Enhanced cosmic-ray antinuclei fluxes with dark matter annihilation into soft unclustered energy patterns

We propose searching for physics beyond the Standard Model in the low-transverse-momentum tracks accompanying hard-scatter events at the LHC. TeV-scale resonances connected to a dark QCD sector could be enhanced by selecting events with anomalies in the track distributions. As a benchmark, a quirk model with microscopic string lengths is developed, including a setup for event simulation. For this model, strategies are presented to enhance the sensitivity compared to inclusive resonance searches: a simple cut-based selection, a supervised search, and a model-agnostic weakly supervised anomaly search with the CATHODE method. Expected discovery potentials and exclusion limits are shown for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>140</mn><mtext> </mtext><mtext> </mtext><msup><mi>fb</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math> of 13 TeV proton-proton collisions at the LHC.

Germany

Sascha Dreyer

Max Fusté Costa

Sarah Heim

Gregor Kasieczka

Louis Moureaux

David Rousso

David Shih

Manuel Sommerhalder

Soft-unclustered-energy patterns from quirks

The Froggatt-Nielsen (FN) mechanism offers an elegant explanation for the observed masses and mixings of Standard Model fermions. In this work, we systematically study FN models in the lepton sector, identifying a broad range of charge assignments (“textures”) that naturally yield viable masses and mixings for various neutrino mass generation mechanisms. Using these textures, we consider higher-dimensional operators consistent with a FN origin and find that natural realizations predict distinct patterns in lepton flavor- and number-violating observables. For Dirac and Majorana neutrinos, FN-related correlations can lead to detectable rates of charged lepton flavor violation at next-generation low-energy experiments. Majorana and type-I seesaw models predict measurable rates of neutrinoless double beta decay. Determination of inverted neutrino mass ordering would exclude the Dirac neutrino FN scenario. Only a small minority of purely leptonic FN models predict detectable flavor violation at future muon colliders, though it is possible that a combined analysis with the quark sector will reveal motivated signals. These findings highlight the power of the FN mechanism to link neutrino mass generation to testable leptonic observables, offering new pathways for the experimental exploration of lepton number and underscoring the importance of next-generation low-energy probes.

Claudia Cornella

Gordan Krnjaic

Micah Mellors

Testing the Froggatt-Nielsen mechanism with lepton flavor and number violating processes

The Froggatt-Nielsen (FN) mechanism is an elegant solution to the flavor problem. In its minimal application to the quark sector, the different quark types and generations have different charges under a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><msub><mo stretchy="false">)</mo><mi>X</mi></msub></math> flavor symmetry. The SM Yukawa couplings are generated below the flavor breaking scale with hierarchies dictated by the quark charge assignments. Only a handful of charge assignments are generally considered in the literature. We analyze the complete space of possible charge assignments with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">|</mo><msub><mi>X</mi><msub><mi>q</mi><mi>i</mi></msub></msub><mo stretchy="false">|</mo><mo>≤</mo><mn>4</mn></math> and perform both a set of Bayesian-inspired numerical scans and an analytical spurion analysis to identify those charge assignments that reliably generate SM-like quark mass and mixing hierarchies. The resulting set of top-20 flavor charge assignments significantly enlarges the viable space of FN models but is still compact enough to enable focused phenomenological study. We then apply our numerical methodology to demonstrate that these distinct charge assignments result in the generation of correlated flavor-violating four-quark operators characterized by significantly varied strengths, potentially differing substantially from the possibilities previously explored in the literature. Future precision measurement of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Δ</mi><mi>F</mi><mo>=</mo><mn>2</mn></math> observables, along with increasingly accurate SM predictions, may therefore enable us to distinguish among otherwise equally plausible FN charges, thus shedding light on the UV structure of the flavor sector.

Ethan T. Neil

Jedidiah O. Thompson

Mapping and probing Froggatt-Nielsen solutions to the quark flavor puzzle

We demonstrate analytically and numerically that “optimized partial dressing” (OPD) thermal mass resummation, which uses gap equation solutions inserted into the tadpole, efficiently tames finite-temperature perturbation theory calculations of the effective thermal potential, without necessitating use of the high-temperature approximation. An analytical estimate of the scale dependence for OPD resummation, standard Parwani resummation (Daisy resummation), and dimensional reduction shows that OPD has similar scale dependence to dimensional reduction, greatly improving Parwani resummation. We also elucidate how to construct and solve the gap equation for realistic numerical calculations, and demonstrate OPD’s improved accuracy for a toy scalar model. OPD’s improved accuracy is most physically significant when the high-temperature approximation breaks down, rendering dimensional reduction unusable and Parwani resummation highly inaccurate, with the latter underestimating the maximal gravitational wave amplitude for the model by 2 orders of magnitude compared to OPD. Our work highlights the need to bring theoretical uncertainties under control even when analyzing broad features of a model. Given the simplicity of the OPD compared to two-loop dimensional reduction, as well as the ease with which this scheme handles departures from the high-temperature expansion, we argue this scheme has great potential in analyzing the parameter space of realistic beyond the Standard Model models.

Jyotirmoy Roy

Japan

Graham White

Gravitational waves and tadpole resummation: Efficient and easy convergence of finite temperature QFT

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.

Okuto Morikawa

Soma Onoda

Hiroshi Suzuki

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

We present the νϕMTH, a Mirror Twin Higgs (MTH) model realizing asymmetric reheating, baryogenesis and twin-baryogenesis through the out-of-equilibrium decay of a right-handed neutrino without any hard  $${\mathbb{Z}}_{2}$$  breaking. The MTH is the simplest Neutral Naturalness solution to the little hierarchy problem and predicts the existence of a twin dark sector related to the Standard Model (SM) by a  $${\mathbb{Z}}_{2}$$  symmetry that is only softly broken by a higher twin Higgs vacuum expectation value. The asymmetric reheating cools the twin sector compared to the visible one, thus evading cosmological bounds on ∆N eff. The addition of (twin-)colored scalars allows for the generation of the visible baryon asymmetry and, by the virtue of the  $${\mathbb{Z}}_{2}$$  symmetry, also results in the generation of a twin baryon asymmetry. We identify a unique scenario with top-philic couplings for the new scalars that can satisfy all cosmological, proton decay and LHC constraints; yield the observed SM baryon asymmetry; and generate a wide range of possible twin baryon DM fractions, from negligible to unity. The viable regime of the theory contains several hints as to the possible structure of the Twin Higgs UV completion. Our results motivate the search for the rich cosmological and astrophysical signatures of twin baryons, and atomic dark matter more generally, at cosmological, galactic and stellar scales.

Gonzalo Alonso-Álvarez

Andrija Rasovic

Zhihan Yuan

Baryogenesis through asymmetric reheating in the mirror twin Higgs

We study confining dark sectors where the lightest hadrons are glueballs. Such models can provide viable dark matter candidates and appear in some neutral naturalness scenarios. In this work, we introduce a new phenomenological model of dark glueball hadronization inspired by the Lund string model. This enables us to make the most physically-motivated predictions for dark glueball phenomenology at the LHC to date. Our model approximately reproduces the expected thermal distribution of hadron species as an emergent consequence of hadronization dynamics. The ability to predict the production of glueball states heavier than the lightest species significantly expands the reach of long-lived glueball searches in MATHUSLA compared to previous simplified estimates. We also characterize regions of parameter space where emerging and/or semivisible jets could arise from pure-glue dark sectors, thereby providing new benchmark models that motivate searches for these signatures.

Switzerland

Timothy Cohen

Graham Kribs

Dark sector glueballs at the LHC

We carefully study the decay and reconstruction of long-lived particle (LLP) decays in the proposed MATHUSLA LLP detector for the HL-LHC. Our investigations are focused on three LLP benchmark models. MATHUSLA’s primary physics target is represented by hadronically decaying LLPs with mass above <math><mo>∼</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, produced in exotic Higgs decays. We also investigate GeV-scale scalar and right-handed neutrino LLPs, which are the target of many other proposed experiments. We first introduce a public mathusla fastsim code to allow for efficient signal-only studies of LLP decays in MATHUSLA and general external LLP detectors. For each of our benchmark scenarios, we carefully simulate LLP production and decay, and make our simulation library publicly accessible for future investigations and comparisons with other experiments. We then systematically study the geometric acceptance of MATHUSLA for LLP decays in these scenarios, and present updated sensitivity projections that include these acceptances. Our results show that the idealized reach of MATHUSLA computed in earlier studies is mostly realized. We also investigate possible ways of increasing the signal acceptance using the inherent geometric flexibility of the FastSim, which will provide useful inputs for realistic experimental and engineering optimization of the detector in the future.