Recently, the peak structure of the sound velocity was observed in the lattice simulation of two-color and two-flavor QCD at the finite quark chemical potential. The comparison with the chiral perturbation theory (ChPT) result was undertaken, however, the ChPT failed in reproducing the peak structure. In this study, to extend the ChPT framework, we incorporate contributions of the $σ$ meson, that is identified as the chiral partner of pions, on top of the low-energy pion dynamics by using the linear sigma model (LSM). Based on the LSM we derive analytic expressions of the thermodynamic quantities as well as the sound velocity within a mean-field approximation. As a result, we find that those quantities are provided by sums of the ChPT results and corrections, where the latter is characterized by a mass difference between the chiral partners, the $σ$ meson and pion. The chiral partner contributions are found to yield a peak in the sound velocity successfully. We furthermore show that the sound velocity peak emerges only when $m_σ>\sqrt{3}m_π$ and $μ_q > m_π$, with $m_{σ(π)}$ and $μ_q$ being the $σ$ meson (pion) mass and the quark chemical potential, respectively. The correlation between the sound velocity peak and the sign of the trace anomaly is also addressed.
Speed of sound and trace anomaly in a unified treatment of the two-color diquark superfluid, the pion-condensed high-isospin matter, and the 2SC quark matter
Enhancement of axial anomaly effects in hot two-color QCD: FRG approach in the linear sigma model
RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所交叉理论数学科学中心（iTHEMS））；Nagoya University（名古屋大学）；Osaka University（大阪大学）
Speed of sound exceeding the conformal bound in dense QCD-like theories
Yukawa Institute for Theoretical Physics, Kyoto University（京都大学汤川理论物理研究所）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS), RIKEN（理化学研究所交叉理论与数学科学中心（iTHEMS））；The Open University of Japan（日本开放大学）；RIKEN Nishina Center, RIKEN（理化学研究所西村中心）；Institute of Science Tokyo（东京科学大学）；Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University（名古屋大学小林-益川粒子与宇宙起源研究所）
FRG analysis of dense two-color QCD within the linear sigma model
Institute of Physics and Astronomy, Eötvös University（罗兰大学物理与天文学研究所）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所跨学科理论与数学科学中心(iTHEMS)）；Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University（名古屋大学小林-益川粒子起源宇宙研究所）；Research Center for Nuclear Physics, Osaka University（大阪大学核物理研究中心）
Two jets and missing $E_T$ signature to determine the spins of the new particles
我们考虑了LHC早期能量加喷流通道中新有色粒子的自旋决定。我们用一个三位驼鹿模型来描述所有相同自旋伙伴（LHT或UED类）模型的低能拉格朗日量，并检验振幅的规范不变性。与超对称模型相比，在基准产生和衰变通道$pp \rightarrow U^{(R)} U^{(R)} \rightarrow u u B_H B_H$中，存在自旋关联，它影响了重伙伴$U^{(R)}$衰变产生的夸克的极角和方位角分布.我们表明，这种影响将是可见的$E_{\rm T miss} / M_{\rm eff}$分布和重建的方位角相关使用MAOS重建。
Chiral partners of strange doubly heavy baryons: Mass relations and decay predictions after the 2026 LHCb discoveries
Institute of Theoretical Physics and Mark Kac Center for Complex Systems Research, Jagiellonian University（雅盖隆大学理论物理研究所与马克·卡克复杂系统研究中心）；Center for Nuclear Theory, Department of Physics and Astronomy, Stony Brook University（石溪大学物理与天文学系核心理论中心）
Constraining free parameters of a color superconducting non-local Nambu-Jona-Lasinio model using Bayesian analysis of neutron stars mass and radius measurements
