The internal structure of the exotic $$P_c$$ and $$P_{cs}$$ pentaquarks remains an open question. To address this, we demonstrate that pion emission serves as a sensitive probe by calculating its properties within a molecular scenario using the chiral quark model and coupled-channel effects. Our results reveal a strong dependence of the decay widths on the internal structure and spatial wave functions within the molecular framework. Notably, the relative ratios of the decay widths among different spin-parity assignments are found to be much more robust against model parameter variations than the absolute values, providing a clean discriminator for quantum numbers. We therefore expect this study to stimulate experimental measurements of these decays, which are crucial for determining the nature of these states and guiding the search for further molecular partners.

China

Li-Cheng Sheng

Yu-Jie Tang

Yu-Xin Wan

Rui Chen

Dian-Yong Chen

Exploring pion emission properties of (strange) hidden-charm molecular pentaquarks in a chiral quark model

In the present work, we studied the $$T_{\bar{c}\bar{s}1}^f(2750)$$ state production through the meson loop mechanism in the $$B^+$$ meson decays, where $$T_{\bar{c}\bar{s}1}^f(2750)$$ is considered as a $$\bar{D}K^*$$ molecular state with $$J^P=1^+$$ . By employing the effective Lagrangian approach, we estimated the branching ratio of the $$B^+ \rightarrow D^+ T_{\bar{c}\bar{s}1}^{f}(2750)$$ and $$B^+ \rightarrow D^{*+} T_{\bar{c}\bar{s}1}^f(2750)$$ processes and found them to be on the order of $$10^{-5}\sim 10^{-4}$$ . The fit fraction of $$T_{\bar{c}\bar{s}1}^f(2750)$$ in different processes was also estimated. We propose to search for $$T_{\bar{c}\bar{s}1}^f(2750)$$ in the $$B^+ \rightarrow D^{*+}\bar{D}^{*-}K^+$$ process, which should be accessible to the Belle II and LHCb Collaborations.

Zhuo Yu

Qi Wu

Zi-Li Yue

$$T_{\bar{c}\bar{s}1}^f(2750)$$ production in the $$B^+$$ decays processes

Femtoscopy offers a sensitive probe of hadron emission sources and hadronic interactions. In this study, we examine relativistic corrections to scattering phase shifts and correlation functions using the two-body Dirac equation framework. We analyze the impact of the Darwin term and spin-dependent potentials, showing that these relativistic effects, especially spin-related interactions, significantly enhance the proton-proton correlation function. Our findings emphasize the necessity of including relativistic corrections for precise femtoscopic analyses.

United States

Zeyu Zeng

Baoyi Chen

Germany

Jiaxing Zhao

Relativistic corrections to hadron-hadron scattering phase shift and correlation function * Baoyi Chen is supported by the National Natural Science Foundation of China (NSFC) (12175165). Jiaxing Zhao is supported by the Helmholtz Research Academy Hessen for FAIR (HFHF)

In this article, the electroweak transition form factors of $$\Sigma _b\rightarrow \Sigma _c,$$ $$\Xi '_b\rightarrow \Xi '_c$$ and $$\Omega _b\rightarrow \Omega _c$$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating current to hadronic states are considered, and the Dirac structure dependence on the form factors is systematically eliminated. In QCD side, our calculation incorporates both the perturbative part and the contributions from vacuum condensates up to dimension 8. This systematic inclusion of higher-dimensional terms accounts for a broader set of Feynman diagrams, thereby enhancing the comprehensiveness and reliability of the operator product expansion. Using the obtained form factors, we study the partial widths of semileptonic decays $$\Sigma _b\rightarrow \Sigma _cl\bar{\nu }_l,$$ $$\Xi '_b\rightarrow \Xi '_cl\bar{\nu }_l$$ and $$\Omega _b\rightarrow \Omega _cl\bar{\nu }_l$$ ( $$l=e,$$ $$\mu $$ and $$\tau $$ ). The results indicate that these decay widths approximately satisfy SU(3) flavor symmetry. Next, we calculate the branching ratios for the decay process $$\Omega _b\rightarrow \Omega _cl\bar{\nu }_l$$ and compare them with the results from other collaborations. Furthermore, the lepton universality ratios and some asymmetry parameters of these decay processes are also analyzed, which provide information for the study of new physics. We hope that these results will serve as a useful reference for future theoretical and experimental studies of weak decays involving heavy flavor baryons.

Jie Lu

Guo-Liang Yu

Zhi-Gang Wang

Bin Wu

Analysis of the semileptonic decays $$\Sigma _b\rightarrow \Sigma _cl\bar{\nu }_l,$$ $$\Xi '_b\rightarrow \Xi '_cl\bar{\nu }_l$$ and $$\Omega _b\rightarrow \Omega _cl\bar{\nu }_l$$ in QCD sum rules

The Galactic Center GeV Excess (GCE) remains a compelling but enigmatic signal from the inner regions of our galaxy. Muonphilic dark matter (DM), which couples exclusively to muons via a new mediator, provides a viable explanation for the GCE and relic density while naturally evading constraints from direct detection, collider searches, and other multimessenger observations. Based on the viable nonresonant parameter space identified in previous global fits, we perform a comprehensive study on the prospects for discovering such muonphilic DM in the context of a future 3 TeV muon collider, focusing on simplified models with a $Z_2$ -even mediator. Four distinct search strategies are investigated: visible on-shell mediator decays ( $\mu^{+}\mu^{-}\gamma$ final state), invisible on-shell mediator decays (mono-photon plus missing energy), mono-photon production via off-shell mediators, and vector boson fusion production. Through a detailed signal-background analysis using cut-and-count methods, we project the exclusion limits at $ 95 $ % confidence level for seven representative models across a wide range of mediator masses. Our results demonstrate that the projected limits cover a significant portion of viable parameter space that explains the GCE, establishing a muon collider as a decisive machine for testing the muonphilic DM hypothesis.

Wanyun Chen

Haoqi Li

Chih-Ting Lu

Qiulei Wang

Exploring muonphilic dark matter with the $\textit{Z}$ $_{2}$-even mediator at muon colliders * Chih-Ting Lu, Wanyun Chen and Haoqi Li are supported by the National Natural Science Foundation of China (NNSFC) (12335005, 12575118) and the Special funds for postdoctoral overseas recruitment, Ministry of Education of China

<p>Motivated by the observations of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>s</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>2900</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>T</mi><mrow><mi>c</mi><mover accent="true"><mi>s</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>2900</mn><msup><mo stretchy="false">)</mo><mrow><mo>+</mo><mo>+</mo></mrow></msup></math>, we propose to search for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mrow><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>s</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>2900</mn><mo stretchy="false">)</mo></mrow><mn>0</mn></msup></math> in the cleaner process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>−</mo></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mo>−</mo></msup><msup><mi>D</mi><mn>0</mn></msup><msup><mi>K</mi><mn>0</mn></msup></math>. In the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><msup><mi>K</mi><mo>*</mo></msup></math> molecular picture, our estimates suggest that <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>s</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>2900</mn><msup><mo stretchy="false">)</mo><mn>0</mn></msup></math> should contribute significantly to the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><msup><mi>K</mi><mn>0</mn></msup></math> invariant mass distribution in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>B</mi><mo>−</mo></msup><mo stretchy="false">→</mo><msup><mi>K</mi><mo>−</mo></msup><msup><mi>D</mi><mn>0</mn></msup><msup><mi>K</mi><mn>0</mn></msup></math>, as reported by the Belle II Collaboration. The corresponding fit fraction is estimated to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>9.72</mn><mo>±</mo><mn>3.92</mn><mo stretchy="false">)</mo><mo>%</mo></math> or <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>7.09</mn><mo>±</mo><mn>5.88</mn><mo stretchy="false">)</mo><mo>%</mo></math> in different fitting schemes. Further precise measurements of this process at Belle II and LHCb could be helpful for clarifying the nature of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>T</mi><mrow><mi>c</mi><mover accent="true"><mi>s</mi><mo stretchy="false">¯</mo></mover><mn>0</mn></mrow></msub><mo stretchy="false">(</mo><mn>2900</mn><mo stretchy="false">)</mo></math>.</p>

Man-Yu Duan

Guan-Ying Wang

Yun Liang

En Wang

Xiang Liu

Finding the clean process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow><mi>B</mi></mrow><mrow><mo>−</mo></mrow></msup><mo stretchy="false">→</mo><msup><mrow><mi>K</mi></mrow><mrow><mo>−</mo></mrow></msup><msup><mrow><mi>D</mi></mrow><mrow><mn>0</mn></mrow></msup><msup><mrow><mi>K</mi></mrow><mrow><mn>0</mn></mrow></msup></mrow></math> to probe absolutely exotic four-quark states

Positive and negative flows of the Chen-Lee-Liu model and its various reductions, including Burgers hierarchy, are formulated within the framework of Riemann-Hilbert-Birkhoff decomposition with the constant grade two generator. Two classes of vacua, namely zero vacuum and constant non-zero vacuum can be realized within a centerless Heisenberg algebra. The tau functions for soliton solutions are obtained by a dressing method and vertex operators are constructed for both types of vacua. We are able to select and classify the soliton solutions in terms of the type of vertices involved. A judicious choice of vertices yields in a closed form a particular set of multi soliton solutions for the Burgers hierarchy. We develop and analyze a class of gauge-Bäcklund transformations that generate further multi soliton solutions from those obtained by dressing method by letting them interact with various integrable defects.

Brazil

Ireland

Y.F. Adans

H. Aratyn

C.P. Constantinidis

J.F. Gomes

G.V. Lobo

T.C. Santiago

New soliton solutions for Chen-Lee-Liu and Burgers hierarchies and its Bäcklund transformations

In this study, we compute the next-to-leading-order QCD corrections to the Dirac electromagnetic form factors of the Σ hyperons within the hard-collinear factorization framework at leading power. The corresponding short-distance coefficient functions are extracted from the relevant seven-point partonic correlation functions. We find that the one-loop radiative corrections to the leading-twist hard-scattering contributions are numerically significant over a broad range of momentum transfer. Combining the perturbatively calculated hard kernels with nonperturbative Σ distribution amplitudes determined from lattice QCD, we present state-of-the-art theoretical predictions for the Σ hyperon electromagnetic form factors.

Bo-Xuan Shi

Hui-Xin Yu

Xue-Chen Zhao

Next-to-leading-order QCD predictions for the Σ Dirac form factors * This research is supported by the National Natural Science Foundation of China (12475097, 12535006) and the Natural Science Foundation of Tianjin (25JCZDJC01190). Xue-Chen Zhao is supported by the Postdoctoral Fellowship Program of CPSF (GZB20250794)

Motivated by the observation of the doubly charmed tetraquark $ T_{cc}(3875)^+ $ , we present a systematic study of doubly heavy tetraquarks ( $ T_{QQ'\bar{q}\bar{q}'} $ ) using heavy antiquark-diquark symmetry (HADS) within a constituent quark model. By calibrating model parameters to known hadron spectra and incorporating the effective mass formula, we predict the masses for 38 ground-state tetraquarks with $ cc $ , $ bb $ , and $ bc $ heavy quark pairs, including the non-strange, single-strange, and double-strange configurations with quantum numbers $ J^P = 0^+, 1^+ $ and $ 2^+ $ . Notably, we identify several stable states below the relevant meson-meson thresholds, particularly in the $ bb\bar{q}\bar{q}' $ sector. The explicit connection between the doubly heavy tetraquark and the heavy baryon spectra through HADS reduces model dependence and reveals the fundamental systematics in the heavy-quark hadron landscape.

Liu-Yu Zhang

Tian-Wei Wu

Yong-Liang Ma

Bridging doubly heavy tetraquark mass spectrum with heavy baryons utilizing heavy antiquark-diquark symmetry * The work of Tian-Wei Wu is supported by the National Natural Science Foundation of China (12405108). Yong-Liang Ma is supported in part by the National Science Foundation of China (NSFC) (12347103) and Gusu Talent Innovation Program (ZXL2024363)

<p>In this work, we investigate the productions of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> in the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi><mover accent="true"><mrow><mi>p</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mo stretchy="false">→</mo><msub><mrow><mover accent="true"><mrow><mi mathvariant="normal">Λ</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow><mrow><mi>c</mi></mrow></msub><msup><mrow><mi>D</mi></mrow><mrow><mn>0</mn></mrow></msup><mi>p</mi></mrow></math> process by utilizing an effective Lagrangian approach, where both <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> are considered as <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup><mi>N</mi></math> molecular states with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>J</mi><mi>P</mi></msup><mo>=</mo><mn>1</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mo>/</mo><msup><mn>2</mn><mo>−</mo></msup></math>, respectively. In addition to the <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>D</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mo>*</mo></msup></math> exchanges, the contribution from light-meson exchange is also considered. At <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>10</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, our estimations indicate that the total cross sections for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>p</mi><mover accent="true"><mi>p</mi><mo stretchy="false">¯</mo></mover><mo stretchy="false">→</mo><msub><mover accent="true"><mi mathvariant="normal">Λ</mi><mo stretchy="false">¯</mo></mover><mi>c</mi></msub><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> are <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><msubsup><mn>130.7</mn><mrow><mo>−</mo><mn>103.9</mn></mrow><mrow><mo>+</mo><mn>397.1</mn></mrow></msubsup><mo stretchy="false">)</mo><mtext> </mtext><mtext> </mtext><mi>nb</mi></math>, where the central value is estimated with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>r</mi></msub><mo>=</mo><mn>1.1</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>, and the uncertainties are resulted from the variation of parameter <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>r</mi></msub></math> from 1.0 to 1.2 GeV. Our results indicate that the light-meson exchange diagrams are very important, which provide a very large, smooth background. Moreover, the estimations of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>D</mi><mn>0</mn></msup><mi>p</mi></math> invariant mass spectrum reveal that the peak structure between 2.9 and 3.0 GeV primarily originates from <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math>, while the signal of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> is about 1 order smaller than that of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math>. Furthermore, the resulting Dalitz plot is estimated with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>8</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math>. It is expected that our estimations in the present work can be tested by future experiments at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mover accent="true"><mrow><mi mathvariant="normal">P</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover><mi>ANDA</mi></mrow></math>.</p>

Quan-Yun Guo

<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2910</mn><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi mathvariant="normal">Λ</mi><mi>c</mi></msub><mo stretchy="false">(</mo><mn>2940</mn><mo stretchy="false">)</mo></math> productions in <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>p</mi><mover accent="true"><mrow><mi>p</mi></mrow><mrow><mo stretchy="false">¯</mo></mrow></mover></mrow></math> annihilation