High Energy Accelerator Research Organization

Chiral Quark Soliton Model And Nucleon Parton Distribution Functions

Masashi Wakamatsu

The chiral quark soliton model (CQSM) is an effective quark model of baryons maximally taking account of the most important feature of low-energy QCD, i.e., the spontaneous chiral…

A quarkyonic matter model

Toru Kojo

Quarkyonic matter is a state of matter in dense QCD whose bulk thermodynamics is dominated by quarks, while low-energy excitations remain confined. This picture leads to a crossove…

Minimal dark $S U (2)$ origin of a massless Dirac neutrino

P. S. Bhupal Dev, Julia Gehrlein, Amartya Sengupta +1

We propose a gauge-symmetry origin of a rank-two Dirac neutrino mass matrix that enforces one exactly massless neutrino, while being consistent with the oscillation data, as well a…

Twist-2 relations for the twist-3 tensor-polarized distribution function $f_{L T}$ of a spin-1 hadron by the operator-product-expansion method

S. Kumano, Kenshi Kuroki

In a spin-1 hadron, tensor-polarized parton distribution functions (PDFs) exist. The twist-2 function is $f_{1 LL}$ and a twist-3 one is $f_{L T}$ . Because an experiment is under pre…

Delineating neutral and charged mesons in magnetic fields

Toru Kojo, Sakura Itatani

We investigate the properties of neutral and charged mesons in magnetic fields, from weak-field to strong-field regimes. To develop analytic insights, we employ a non-relativistic…

Multi-channel phase space with Feynman-diagram-gauge amplitudes

Kaoru Hagiwara, Junichi Kanzaki, Fabio Maltoni +2

Multi-channel phase space with a single Feynman diagram enhancement is a powerful tool for high-energy physics event generation if a diagram with a singular propagator dominates th…

hep-ph2026★ 1 cited

Cavity, lumped-circuit, and spin-based detection of axion dark matter: differences and similarities

Deniz Aybas, Hendrik Bekker, Dmitry Budker +12

Axions and axion-like particles are compelling candidates for ultralight bosonic dark matter, forming coherent oscillating fields that can be probed by experiments known as halosco…

Analytical study of birefringent cavities for axion-like dark matter search

Tadashi Kuramoto, Yasutaka Imai, Takahiko Masuda +3

Light polarization plays a crucial role in optical-cavity experiments; however, mirror birefringence presents a significant challenge that must be addressed carefully. In this stud…

Thermal quarks and Polyakov loops in two-color dense QCD

Yugo Kurebayashi, Toru Kojo, Daiki Suenaga

We study confinement and deconfinement in dense two color QCD by analyzing the dynamics of thermal quarks and gluons. The Polyakov loop is used as a probe of the relevant thermal e…

Impact of dim-6 $ν$ SMEFT operators on low-scale leptogenesis

Kaori Fuyuto, Julia Harz, Sascha Weber

We investigate the impact of higher-dimensional operators on low-scale leptogenesis (LG) via oscillations of right-handed neutrinos within the neutrino-extended Standard Model Effe…

New Bounds on Heavy QCD Axions from Big Bang Nucleosynthesis

Tae Hyun Jung, Takemichi Okui, Kohsaku Tobioka +1

We study Big Bang Nucleosynthesis (BBN) constraints on heavy QCD axions. BBN offers a powerful probe of new physics that modifies the neutron-to-proton ratio during the process, th…

Revisiting the limits on dark matter annihilation cross-section and decay lifetime in light of electron and positron fluxes

Nagisa Hiroshima, Kazunori Kohri, Partha Kumar Paul +1

We revisit the upper bound on the annihilation cross-section, $⟨ σ v ⟩$ of a stable dark matter (DM) of mass $500 - 1 0^{14}$ GeV by considering five different channels: $W^+…

Oscillation-Independent Probes of Neutrino Non-Standard Interactions from Supernovae

Angela R. Beatty, Anna M. Suliga, Volodymyr Takhistov

Extreme astrophysical environments provide unique laboratories for testing fundamental neutrino interactions. We present the first oscillation-independent astrophysical probe of no…

Tensor-polarized twist-3 parton distribution functions $f_{L T} (x)$ for the spin-1 deuteron by using twist-2 relations

S. Kumano, Kenshi Kuroki

Tensor-polarized twist-3 parton distribution functions (PDFs) $f_{L T} (x)$ are calculated for the spin-1 deuteron by using twist-2 relations, which are similar to the Wandzura-Wilcz…

Prospects for toponium formation at the LHC in the single-lepton mode

Benjamin Fuks, Kaoru Hagiwara, Kai Ma +2

We investigate the formation of toponium in the single-leptonic final state at the LHC. Our study builds on our recently proposed framework that incorporates the associated non-per…

hep-ph2025★ 4 cited

Studying the in-medium $ϕ$ meson spectrum through kaons in proton-nucleus reactions

Gabor Balassa, Kazuya Aoki, Philipp Gubler +3

Exploring the mass modifications of $ϕ$ mesons in nuclei provides insights into the nature of strongly interacting matter. Specifically, $ϕ$ meson mass shifts can be related to the…

hep-ph2025★ 2 cited

Cosmic-ray boosted inelastic dark matter from neutrino-emitting active galactic nuclei

R. Andrew Gustafson, Gonzalo Herrera, Mainak Mukhopadhyay +2

Cosmic rays may scatter off dark matter particles in active galactic nuclei, where both the densities of cosmic rays and dark matter are expected to be very large. These scattering…

hep-ph2025★ 1 cited

Unified Gas Heating Constraints on Extended Dark Matter Compact Objects

TaeHun Kim, Philip Lu, Volodymyr Takhistov

We present the first unified constraints on a broad class of extended dark matter compact objects (EDCOs) from interstellar gas heating. These include axion stars, Q-balls, axion m…

hep-ph2025★ 4 cited

Semi-inclusive deep inelastic scattering off a tensor-polarized spin-1 target

Jing Zhao, Alessandro Bacchetta, Shunzo Kumano +2

We investigate the semi-inclusive deep inelastic scattering off a tensor-polarized spin-1 target, focusing on the production of an unpolarized hadron. The complete differential cro…

hep-ph2025★ 1 cited

Dynamical dark energy in the no-scale Brans-Dicke gravity

Muzi Hong, Kyohei Mukaida, Tsutomu T. Yanagida

We add a new scalar field in the no-scale Brans-Dicke gravity and require it to have a global O(2) symmetry with the original scalar field in the Brans-Dicke gravity. This gives us…

Wess-Zumino-Witten Interactions of Axions: Three-Flavor

Yang Bai, Ting-Kuo Chen, Jia Liu +1

We present a complete Lagrangian describing axion interactions with pseudoscalar and (axial-)vector mesons within the three light-flavor quark framework. This formulation incorpora…