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Probing Dark Jets from Higgs Decays at LHC

Published:Dec 31, 2025 12:00
1 min read
ArXiv

Analysis

This paper explores a novel search strategy for dark matter, focusing on a specific model where the Higgs boson decays into dark sector particles that subsequently produce gluon-rich jets. The focus on long-lived dark mesons decaying into gluons and the consideration of both cascade decays and dark showers are key aspects. The paper highlights the importance of trigger selection for detection and provides constraints on the branching ratios at the high-luminosity LHC.
Reference

The paper finds that appropriate trigger selection constitutes a crucial factor for detecting these signal signatures in both tracker system and CMS muon system. At the high-luminosity LHC, the exotic Higgs branching ratio to cascade decays (dark showers) can be constrained below $\mathcal{O}(10^{-5}-10^{-1})$ [$\mathcal{O}(10^{-5}-10^{-2})$] for dark meson proper lifetimes $c\tau$ ranging from $1$ mm to $100$ m.

Analysis

This paper presents a cutting-edge lattice QCD calculation of the gluon helicity contribution to the proton spin, a fundamental quantity in understanding the internal structure of protons. The study employs advanced techniques like distillation, momentum smearing, and non-perturbative renormalization to achieve high precision. The result provides valuable insights into the spin structure of the proton and contributes to our understanding of how the proton's spin is composed of the spins of its constituent quarks and gluons.
Reference

The study finds that the gluon helicity contribution to proton spin is $ΔG = 0.231(17)^{\mathrm{sta.}}(33)^{\mathrm{sym.}}$ at the $\overline{\mathrm{MS}}$ scale $μ^2=10\ \mathrm{GeV}^2$, which constitutes approximately $46(7)\%$ of the proton spin.

Charm Quark Evolution in Heavy Ion Collisions

Published:Dec 29, 2025 19:36
1 min read
ArXiv

Analysis

This paper investigates the behavior of charm quarks within the extreme conditions created in heavy ion collisions. It uses a quasiparticle model to simulate the interactions of quarks and gluons in a hot, dense medium. The study focuses on the production rate and abundance of charm quarks, comparing results in different medium formulations (perfect fluid, viscous medium) and quark flavor scenarios. The findings are relevant to understanding the properties of the quark-gluon plasma.
Reference

The charm production rate decreases monotonically across all medium formulations.

Analysis

This paper investigates how the properties of hadronic matter influence the energy loss of energetic partons (quarks and gluons) as they traverse the hot, dense medium created in heavy-ion collisions. The authors introduce a modification to the dispersion relations of partons, effectively accounting for the interactions with the medium's constituents. This allows them to model jet modification, including the nuclear modification factor and elliptic flow, across different collision energies and centralities, extending the applicability of jet energy loss calculations into the hadronic phase.
Reference

The paper introduces a multiplicative $(1 + a/T)$ correction to the dispersion relation of quarks and gluons.

Lepton-Gluon Portal Models

Published:Dec 26, 2025 18:52
1 min read
ArXiv

Analysis

This paper investigates new physics models that extend the Standard Model by introducing exotic particles that interact with both leptons and gluons. It explores the parameter space of these models, considering various effective operators and their potential collider signatures. The focus on asymmetric portals and the exploration of different SU(3) and SU(2) quantum numbers for the exotic states are key aspects of the research.
Reference

The paper explores potential single-production modes and their phenomenological signatures at colliders.