We constructed a four-Higgs-doublet model (4HDM) invariant under $\textit{D}$ $_{5}$ symmetry and investigated its complete neutral vacuum structure in detail. Assuming explicit CP conservation in the scalar potential, we examined whether CP symmetry can be spontaneously broken. We provided a complete list of all possible real and complex vacua, along with the constraints on the potential parameters required for each vacuum solution to exist. We also discussed the positive-definiteness conditions that the Hessian must satisfy for each vacuum to be a local minimum of the potential. The results show that, after spontaneous symmetry breaking, some complex vacua lead to spontaneous CP violation in the potential, whereas the remaining complex vacua still preserve CP conservation. Among these CP-violating complex vacua, one can be regarded as the most general form. Furthermore, we discussed the relationship between real and complex vacua.

China

Dong-Ping Fu

Michihisa Takeuchi

Spontaneous CP violation in the $\textit{D}$ $_{5}$-symmetric four-Higgs-doublet models * Supported by the Fundamental Research Funds for the Central Universities, the One Hundred Talent Program of Sun Yat-sen University, China, and the Guangdong Natural Science Foundation (2026A1515012641)

We investigate the reaction mechanism of strangeness production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><mi>ϕ</mi><mi mathvariant="normal">Λ</mi></math> within a hybrid Regge framework, taking into account <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-channel <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>- and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>*</mo></msup></math>-Reggeon exchanges. We present results for the total cross section, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>t</mi></math>-dependent differential cross sections, and spin-density matrix elements (SDMEs), and compare them with the available experimental data. We find that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>*</mo></msup></math>-Reggeon exchange provides the dominant contribution, while <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>K</mi></math>-Reggeon exchange remains non-negligible, particularly in describing the SDMEs. In contrast, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>-channel <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Λ</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>u</mi></math>-channel nucleon exchanges are negligible. To obtain reliable predictions for the open-charm production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msubsup><mi>D</mi><mi>s</mi><mrow><mo>*</mo><mo>−</mo></mrow></msubsup><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math>, we employ a quark-gluon-string-model-motivated Regge prescription that incorporates both pseudoscalar- and vector-Reggeon exchanges. Within this prescription, the Regge trajectories <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>α</mi><mo stretchy="false">(</mo><mi>t</mi><mo stretchy="false">)</mo></math> and energy-scale parameters <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>s</mi><mn>0</mn></msub></math> are determined consistently, thereby constraining the model and reducing theoretical ambiguities. For the hidden-charm production in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Λ</mi></math>, we use the same quark-level diagrammatic correspondence. The total cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><msubsup><mi>D</mi><mi>s</mi><mrow><mo>*</mo><mo>−</mo></mrow></msubsup><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Λ</mi></math> are suppressed by approximately 4–6 and 8–9 orders of magnitude, respectively, compared with that for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>K</mi><mo>−</mo></msup><mi>p</mi><mo stretchy="false">→</mo><mi>ϕ</mi><mi mathvariant="normal">Λ</mi></math>. We also examine possible <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>s</mi></math>-channel contributions from the hidden-charm pentaquark states with strangeness, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub><mo stretchy="false">(</mo><mn>4338</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>P</mi><mrow><mi>c</mi><mi>s</mi></mrow></msub><mo stretchy="false">(</mo><mn>4459</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math>, to both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mi>s</mi><mrow><mo>*</mo><mo>−</mo></mrow></msubsup><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Λ</mi></math> production.

South Korea

Sang-Ho Kim

Production of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>ϕ</mi><mi mathvariant="normal">Λ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msubsup><mi>D</mi><mi>s</mi><mrow><mo>*</mo><mo>−</mo></mrow></msubsup><msubsup><mi mathvariant="normal">Λ</mi><mi>c</mi><mo>+</mo></msubsup></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mi mathvariant="normal">Λ</mi></math> in kaon-induced reactions off the nucleon

We investigate how the temperature influences the threshold cusps in meson-meson scatterings, i.e., <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>D</mi><msup><mover accent="true"><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></mrow></math> (or <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><msup><mi>D</mi><mo>*</mo></msup><mover accent="true"><mi>D</mi><mo>¯</mo></mover></mrow></math>) scatterings, using the production rates and propagators obtained at finite temperature. The line shape of production rate of <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> at different temperatures demonstrates that the cusp structure in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> scattering is mildly enhanced as the temperature increases. For the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> propagator, which includes isospin symmetry breaking, the line shape displays a unique plateaulike structure, and this structure will also be enhanced as the temperature increases. For comparison, the line shape of the <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>D</mi><msup><mover accent="true"><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></mrow></math> propagator including isospin symmetry breaking is also investigated at different temperatures. As the temperature increases, its line shape shows a similar plateaulike structure but with some different properties when the temperature modifications to the masses and widths of <math xmlns="http://www.w3.org/1998/Math/MathML"><mi>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><msup><mover accent="true"><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></math> are considered.

Japan

Ying Zhang

Atsushi Hosaka

Qian Wang

Shigehiro Yasui

Finite-temperature effects on the threshold cusps in <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>π</mi><mi>π</mi></mrow></math> and <math xmlns="http://www.w3.org/1998/Math/MathML"><mrow><mi>D</mi><msup><mover accent="true"><mi>D</mi><mo>¯</mo></mover><mo>*</mo></msup></mrow></math> scatterings from relativistic heavy-ion collisions

We investigate a non-Abelian SU(2) quantum link model in $$2+1$$ dimensions on a hexagonal lattice using tensor network methods. We determine the static quark potential for a wide range of bare coupling values and find that the theory is confining. We also probe the existence of a Lüscher term and find a clear signal with a $$g^2$$ dependent coefficient, in qualitative agreement with a strong coupling expansion. Correspondingly, the width of the strings scales logarithmically with the string length again for all $$g^2$$ -values, providing evidence for a rough string, with no indication for a roughening transition.

Germany

Paul Ludwig

Timo Jakobs

Carsten Urbach

Scaling and Lüscher term in a non-Abelian (2+1)d SU(2) quantum link model

Auxiliary field techniques have recently gained interest in four-dimensional non-linear electrodynamics and two-dimensional integrable sigma models. In these settings, coupling a suitable “seed” theory to auxiliary fields provides a powerful mechanism to generate infinite families of models while preserving key dynamical properties, such as electromagnetic duality invariance in four dimensions and classical integrability in two dimensions. Deformations induced through auxiliary fields are closely related to $$ T\overline{T} $$ -like deformations and, in two dimensions, also to their higher-spin generalisations. In this paper, we analyse and clarify the relations between different auxiliary field formulations in two and four dimensions, showing how they are governed by Legendre transformations of the interaction functions combined with appropriate field redefinitions. In four-dimensional electrodynamics, we establish a correspondence between the auxiliary field model of Russo and Townsend and the Ivanov-Zupnik formalism. In two dimensions, we develop the analogue of the Ivanov-Zupnik $\textit{μ}$-frame to deform Principal Chiral, symmetric-space, non-Abelian T-dual, and (bi-)Yang-Baxter sigma models. We discuss how integrability is preserved and use properties of the $\textit{μ}$-frame to further extend known families of integrable deformations.

Australia

Nicola Baglioni

Thailand

Daniele Bielli

Michele Galli

Gabriele Tartaglino-Mazzucchelli

Relating auxiliary field formulations of 4$\textit{d}$ duality-invariant and 2$\textit{d}$ integrable field theories

For the worldline theory of an extremal black hole, extremality amounts to vanishing ground state energy. In light of recent gravity results one would expect much like the ground-state degeneracy, this fine tuned condition too will not be satisfied. It is unclear, however, whether this should be a quantum artefact or classical effect. In this paper we consider a non-BPS extremal four-charge Reissner Nordström black hole in 𝒩 = 8 String theory. It is shown that the microscopic D-brane description fails to admit any extremal state, even classically. This positive energy is expected to destabilize the near-horizon $\textit{AdS}$ . The positive minimum energy is a direct consequence of the pattern of supersymmetry breaking by the D-branes. The black hole entropy is found to be the logarithm of the number of isolated minima and hence is related to the configurational entropy of the microscopic potential. We also find multiple continua of local minima corresponding to marginally bound states of the constituent D-branes.

India

Pranav Kumar

Swapnamay Mondal

Classical unattainability of extremality in non-BPS D-brane systems

In this paper, we explore <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mn>2</mn><mo>+</mo><mn>1</mn><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></mrow></math> quantum electrodynamics at finite density on a quantum computer, including two fermion flavors. Our method employs an established gauge-invariant Ansatz together with a quantum circuit structure that enforces Gauss’s law. As a proof of principle, we benchmark our simulation protocol on a small lattice system of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mo>×</mo><mn>2</mn></math>, demonstrating the identification of density-induced level crossings in terms of the particle number of the fermion flavors. Classical simulations are used to obtain optimized variational parameters, which are then deployed in inference runs on IBM quantum hardware. We conclude by discussing hardware limitations and prospects for scaling this method to larger systems.

Emil Otis Rosanowski

Arianna Crippa

Lena Funcke

Cyprus

Paulo Vitor Itaboraí

Karl Jansen

Simran Singh

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mo stretchy="false">(</mo><mrow><mn>2</mn><mo>+</mo><mn>1</mn></mrow><mo stretchy="false">)</mo><mi mathvariant="normal">D</mi></mrow></math> quantum electrodynamics at finite density on a quantum computer

In this work, we investigate the production and decay of molecular states with quark content $cc\bar c\bar q$ and $J^P=1^+$ using a phenomenological analysis and an effective Lagrangian approach. Based on an $\textit{SU}$(3) flavor-symmetry analysis to identify golden channels, we further explore the dynamics of these processes under the molecular assumptions of ${\eta_c D^*}$ and ${J/\psi D^*}$ . Our results indicate that the production branching ratio in $B_c$ decays is sizable: it can be of order $10^{-4}$ for the molecular configuration ${{\eta}_cD^*}$ and $10^{-5}$ for the molecule ${J/\psi D^*}$ . In addition, we find that the decay widths of the two molecular configurations ${{\eta}_cD^*}$ and ${J/\psi D^*}$ are not significant, at the level of ${\cal{O}}$ ( $\text{MeV}$ ).

Na Li

Ye Xing

Jing-Rui Shi

Analysis of molecular state $\textit{η$_{c}$D}$ $^{*}$ and $\textit{J}$/$\textit{ψD}$ $^{*}$ in the effective Lagrangian approach * Supported by the National Natural Science Foundation of China (NSFC) (12005294)

The Kerr/CFT correspondence establishes a correspondence between extremal black holes in higher dimensions and a chiral conformal field theory (CFT) in their near-horizon limit. A generalization of this framework, known as the EVH/CFT correspondence, has been developed for four- and five-dimensional AdS black holes. It was further proposed in [ ${\rm{AdS}}_{D=6,7}$ black holes, a generalized duality between $(D-2)$ -dimensional geometry and $(D-3)$ -dimensional field theory may emerge in a suitably defined extremal vanishing horizon (EVH) limit. In this work, we show that, in the EVH limit, the near-EVH geometries of these ${\rm{AdS}}_{D=6,7}$ black holes reduce to lower-dimensional black holes whose metrics are conformally related to solutions of Einstein-Maxwell-Maxwell-dilaton (EMMD) gravity. This structural resemblance suggests a potential route toward the microscopic counting of non-AdS black hole entropy via higher-dimensional AdS/CFT techniques.

Weichao Bu

Yang Lei

Probing decoupled throats of AdS $\textit{D}$ black holes in $\textit{D}$ = 6, 7 * Supported by National Natural Science Foundation of China (NSFC) (2305081), the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), and the NSFC-Royal Society International Collaboration (W2421035)

The <math altimg='si14.svg'><mrow><mi>&#954;</mi><mo linebreak='goodbreak'>/</mo><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mrow><mo>(</mo><mn>700</mn><mo>)</mo></mrow></mrow></math> meson remains the most elusive of the light scalar resonances, with its presence in weak decays obscured by limited precision in branching fraction measurements. As a result, the true nature of the <italic>&#954;</italic> remains difficult to explore. Through a partial-wave analysis of the semileptonic decay <math altimg='si15.svg'><mrow><msup><mi>D</mi><mo>+</mo></msup><mo>&#8594;</mo><msup><mi>K</mi><mo>&#8722;</mo></msup><msup><mi>&#960;</mi><mo>+</mo></msup><msup><mi>e</mi><mo>+</mo></msup><msub><mi>&#957;</mi><mi>e</mi></msub></mrow></math>, we extract <math altimg='si16.svg'><mrow><mi mathvariant='script'>B</mi><mrow><mo>(</mo><msup><mi>D</mi><mo>+</mo></msup><mo>&#8594;</mo><msup><mover accent='true'><mi>&#954;</mi><mo>&#175;</mo></mover><mn>0</mn></msup><msup><mi>e</mi><mo>+</mo></msup><msub><mi>&#957;</mi><mi>e</mi></msub><mo>,</mo><msup><mover accent='true'><mi>&#954;</mi><mo>&#175;</mo></mover><mn>0</mn></msup><mo>&#8594;</mo><msup><mi>K</mi><mo>&#8722;</mo></msup><msup><mi>&#960;</mi><mo>+</mo></msup><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mrow><mo>(</mo><mn>2.8</mn><mo>&#177;</mo><mn>1.3</mn><mo>)</mo></mrow><mo linebreak='goodbreak'>&#215;</mo><msup><mn>10</mn><mrow><mo>&#8722;</mo><mn>3</mn></mrow></msup></mrow></math>, revealing a contribution previously regarded as negligible. The extracted form factor, <math altimg='si17.svg'><mrow><msup><mi>f</mi><mo>+</mo></msup><mrow><mo>(</mo><mn>0</mn><mo>)</mo></mrow><mo linebreak='goodbreak'>=</mo><mn>0.39</mn><mo>&#177;</mo><mn>0.08</mn></mrow></math>, provides the first evidence for the <italic>D</italic>&#8239;&#8594;&#8239; <italic>&#954;</italic> transition in weak decays. Remarkably, it lies well below the <math altimg='si18.svg'><mrow><mi>q</mi><mover accent='true'><mi>q</mi><mo>&#175;</mo></mover></mrow></math> prediction of 0.82&#8239;&#177;&#8239;0.05, yet is in excellent agreement with the <math altimg='si19.svg'><mrow><msup><mi>q</mi><mn>2</mn></msup><msup><mover accent='true'><mi>q</mi><mo>&#175;</mo></mover><mn>2</mn></msup></mrow></math> expectation of 0.36&#8239;&#177;&#8239;0.02. Together, these findings offer new evidence supporting a compact tetraquark interpretation of the <italic>&#954;</italic> meson.

Yan-Li Wang

Jia-Nan Fan

Xiao-Yu Hao

Yu-Kuo Hsiao

Probing the elusive <math altimg='si14.svg'><mrow><mi>&#954;</mi><mo linebreak='goodbreak'>/</mo><msubsup><mi>K</mi><mn>0</mn><mo>*</mo></msubsup><mrow><mo>(</mo><mn>700</mn><mo>)</mo></mrow></mrow></math> resonance in semileptonic <italic>D</italic> decays