We revisit confinement/deconfinement transition in holographic QCD to consider the back-reaction of a bulk scalar field. The bulk scalar field is dual to a quark bi-linear operator $\bar qq$, and it encodes explicit and spontaneous chiral symmetry breaking of QCD. To perform the Hawking-Page transition analysis with the back-reaction, we first obtain a deformed AdS black hole solution due to a finite quark mass. Through the Hawking-Page analysis with the back-reacted geometry, we study the flavor number $N_f$ and finite quark mass dependence of the critical temperature of the QCD confinement/deconfinement transition. In addition, we confirm that unphysical QCD phase haunting around in a previous study disappears with the back-reaction. We discuss our results in the light of lattice QCD observations.
Flavor-Dependent Dynamical Spin-Orbit Coupling in Light-Front Holographic QCD: A New Approach to Baryon Spectroscopy
Department of Physics and Astronomy, University of California, Los Angeles（加州大学洛杉矶分校物理与天文学系）；Department of Physics and Astronomy University of California Los Angeles（加州大学洛杉矶分校物理与天文学系）
We establish a holographic QCD model for four flavors, where a light scalar field $X$ and a heavy scalar field $H$ are introduced, separately. The $H$ field is responsible for the breaking of $SU(N_f=4)$ to $SU(N_f=3)$. The ground state and its Regge excitation of meson spectra in the light flavor sector and heavy flavor sector as well as the ligh-heavy mesons are well in agreement with the Particle data group (PDG). Due to the additional introduction of the $H$ field in the model, different Regge slopes for light and heavy mesons can be achieved.
Toward a holographic realization of the 2+1-flavor QCD phase structure
Hunan University（湖南大学）；Hangzhou Institute for Advanced Study, UCAS（杭州高等研究院，中国科学院大学）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；University of Chinese Academy of Sciences (UCAS)（中国科学院大学）；International Center for Theoretical Physics Asia-Pacific (ICTP-AP), UCAS（亚太理论物理国际中心（ICTP-AP），中国科学院大学）；Hunan Provincial Key Laboratory of High-Energy Scale Physics and Applications, Hunan University（湖南大学高能标物理与应用湖南省重点实验室）
Neutrino Masses from an A4 Symmetry in Holographic Composite Higgs Models
我们表明，全息复合希格斯模型与离散A4对称性自然预测层次带电轻子质量和近似的三双极大轻子混合与正确的中微子质量的规模。它们还满足电弱精密测试、轻子味破坏和轻子混合在大范围参数空间中的电流约束。在这些模型中出现了两个现象学上相关的特征。首先，对轻子汤川耦合的额外抑制使τ轻子比从其质量天真地预期的更复杂。因此，新的轻轻子共振，质量低至几百GeV，大耦合到τ和一个非常典型的对撞机现象，是很有可能的。其次，离散对称性A4与模型结构一起提供了双层风味保护，其允许将树水平介导的过程保持在当前实验极限以下。然而，违反轻子味道的单圈过程，如mu -> e gamma，可能在未来的实验中观察到。
Bayesian Inference of the Critical Endpoint in 2+1-Flavor System from Holographic QCD
Central China Normal University（华中师范大学）；University of South China（南华大学）；INFN – Istituto Nazionale di Fisica Nucleare – Sezione di Bari（意大利国家核物理研究所巴里分部）；The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen)（香港中文大学（深圳））；Frankfurt Institute for Advanced Studies（法兰克福高等研究院）；University of Chinese Academy of Sciences（中国科学院大学）
We consider an improved soft-wall AdS/QCD model coupled to an Einstein-dilaton system, which offers a way to study the deconfining and chiral transitions simultaneously. The correlation between these two transitions has been investigated in detail in the Einstein-dilaton-scalar system with the bulk scalar field representing the vacuum of matters in the flavor sector of the model. We find that the effects of the scaling dimension $Δ$ of the dual operator of the dilaton manifest in chiral transitions, although the equation of state can all be matched with the two-flavor lattice results for $Δ=2.…
Quark flavors in hot and dense holographic QCD: setup and comparison to data
Asia Pacific Center for Theoretical Physics（亚太理论物理中心）；Department of Physics, Pohang University of Science and Technology（浦项科技大学物理系）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）；Institute for Theoretical Physics, University of Heidelberg（海德堡大学理论物理研究所）
Systematic Bayesian investigation of the (2+1)-flavor QCD phase transition in a holographic model
State Key Laboratory of Nuclear Physics and Technology, Institute of Quantum Matter, South China Normal University（华南师范大学核物理与技术国家重点实验室量子物质研究所）；Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter, Guangdong Provincial Key Laboratory of Nuclear Science（广东省物质结构与基本相互作用卓越研究中心广东省核科学重点实验室）；School of Nuclear Science and Technology, University of South China（南华大学核科学与技术学院）；INFN – Istituto Nazionale di Fisica Nucleare – Sezione di Bari（意大利国家核物理研究院巴里分部）；School of Science and Engineering, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen)（香港中文大学（深圳）理学院）；School of Artificial Intelligence, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen)（香港中文大学（深圳）人工智能学院）；Key Laboratory of Quark and Lepton Physics (MOE) and Institute of Particle Physics, Central China Normal University（华中师范大学夸克与轻子物理教育部重点实验室粒子物理研究所）；School of Nuclear Science and Technology, University of Chinese Academy of Sciences（中国科学院大学核科学与技术学院）
A holographic model of probe quarkonia is presented, where the dynamical gravity-dilaton background is adjusted to the thermodynamics of 2 +1 flavor QCD with physical quark masses. The quarkonia action is modified to account for a systematic study of the heavy-quark mass dependence. We focus on the $J/ψ$ and $Υ$ spectral functions and relate our model to heavy quarkonia formation as a special aspect of hadron phenomenology in heavy-ion collisions at LHC.
A holographic model of probe vector mesons (quarkonia) is presented, where the dynamical gravity-dilaton background is adjusted to the thermodynamics of 2 +1 flavor QCD with physical quark masses. The vector meson action is modified to account for various quark masses. We focus on the $Φ$, $J/ψ$ and $Υ$ meson melting in agreement with hadron phenomenology in heavy-ion collisions at LHC, that is the formation of hadrons at the observed freeze-out temperature of 155 MeV.
