We investigate the quasinormal modes (QNMs) and greybody factors of dilaton–Euler–Heisenberg (dEH) de Sitter (dS) black holes in string-inspired Euler–Heisenberg gravity. Since the axial gravitational and electromagnetic perturbations decouple, we analyze them independently. By applying the asymptotic iteration method (AIM) together with a sixth-order WKB approximation, we compute the quasinormal frequencies and find excellent agreement between the two methods. We also find that the QNM spectra depend sensitively on the magnetic charge $Q_{\text{m}}$ , cosmological constant Λ, and nonlinear coupling $\epsilon$ , with a notable topological anomaly appearing in the electromagnetic frequency trajectories. Additionally, larger values of $Q_{\text{m}}$ or the multipole number $\textit{l}$ generally suppress wave transmission, while the electromagnetic sector with $\epsilon=1$ exhibits an anomalous response.

Ming Zhang

Guo-Xin Chen

China

Xufen Zhang

Cheng-Fu Feng

Sheng-Yuan Li

Rui-Hong Yue

De-Cheng Zou

Quasinormal frequencies and greybody factors for axial perturbations of dilaton–Euler–Heisenberg de Sitter black holes * This research was supported by the National Natural Science Foundation of China (NNSFC) (12365009), the Natural Science Basic Research Program of Shaanxi Province (2026JC-YBMS-0083), and the Jiangxi Provincial Natural Science Foundation (20262BAC240347)

We study the isospin-violating $J/\psi \to \Lambda\bar \Sigma^0 \eta $ reaction, recently measured by the BESIII collaboration, by considering the dominant terms involving $\bar \Sigma^0$ and pairs of pseudoscalar-baryon particles that together form an $\textit{SU}$(3) singlet and can therefore couple to the $J/\psi$ . We then allow these pairs to undergo final-state interaction to produce the final $\eta \Lambda$ . We find that the relevant original channels are $\bar K N$ and $K \Xi$ , and that the incomplete cancellation of terms involving charged and neutral particles, owing to their different masses, is responsible for the reaction. With this mechanism, we find good agreement with the three experimental mass distributions.

Spain

Lian-Rong Dai

Wen-Tao Lyu

E. Oset

Study of the $ {{\boldsymbol J}/\boldsymbol\psi\bf\to \boldsymbol\Lambda\bar{\boldsymbol\Sigma}^{\bf 0}\boldsymbol\eta}$ reaction * This work is partly supported by the National Natural Science Foundation of China (12575082). This work is partly supported by the National Key R&D Program of China (2024YFE0105200), the Natural Science Foundation of Henan (252300423951), the National Natural Science Foundation of China (12475086), and the Zhengzhou University Young Student Basic Research Projects for PhD students (ZDBJ202522). This work is also partly supported by the Spanish Ministerio de Economia y Competitividad (MINECO) and European FEDER funds (FIS2017-84038-C2-1-PB, PID2020-112777GB-I00), and Generalitat Valenciana (PROMETEO/2020/023). This project has received funding from the European Union Horizon 2020 research and innovation program (H2020-INFRAIA-2018-1, 824093 of the STRONG-2020 project)

In recent years, long-lived particles (LLPs) have attracted increasing attention in searches for physics beyond the Standard Model (SM). In this paper, we investigate the discovery prospects for light, long-lived ALPs predicted by the photophobic ALP scenario through displaced-vertex signals at the CEPC, with a center-of-mass energy of $ \sqrt{s}=91.2 $ GeV and an integrated luminosity of $ {\cal{L}}= $ 100 ab$^{−1}$. After comparing several possible single-production processes for the photophobic ALP, we focus on the dominant process $ e^+ e^- \to Z \to a \gamma $ , in which the ALP $\textit{a}$ subsequently decays into a pair of charged leptons at a displaced vertex. Dedicated Monte Carlo simulations are performed for the $ \mu^+ \mu^- \gamma $ and $ \tau_h^+ \tau_h^- \not{E}_T \gamma $ signals. For the $ \mu^+\mu^-\gamma $ signal, the CEPC is sensitive to the parameter region $ g_{aWW} \in [1.27\times10^{-3},6.80\times10^{-1}]\; {\rm{TeV}}^{-1} $ for $ m_a \in [1,4]\; {\rm{GeV}} $ . For the $ \tau_h^+\tau_h^-\not{E}_T\gamma $ signal, the accessible region is $ g_{aWW} \in [7.00\times10^{-4},9.40\times10^{-3}]\; {\rm{TeV}}^{-1} $ for $ m_a \in [4,9]\; {\rm{GeV}} $ . These results demonstrate the substantial potential of the CEPC to explore light, long-lived ALPs through displaced-vertex signals, providing complementary coverage to existing searches at LEP and the LHC, as well as to the projected reach of the HL-LHC.

Chong-Xing Yue

Xin-Yang Li

Prospects for probing light photophobic axion-like particles via displaced vertex signals at the CEPC * This work was partially supported by the National Natural Science Foundation of China (12575106) and the Cultivation Fund of Liaoning Normal University for Excellent Doctoral Dissertations (YJSYB202501)

We demonstrate that mass inequalities for hadrons containing one or more heavy quarks arise primarily from the concavity of binding energies in the quark model, reflecting short-range Coulombic interactions and long-range confinement. Empirical two-body bindings $ B_{i\bar{j}} $ are extracted from spin-averaged meson masses, ensuring model independence and direct use of experimental data. Fitting these quantities as functions of the reduced mass $ \mu_{ij} $ reveals a critical confinement scale of 1.34 fm, at which the bindings become positive. The concavity of $ B(1/\mu) $ motivates Jensen-like relations under flavor permutation, reproducing relations such as $ m_{x\bar{y}} \gt \dfrac{1}{2}(m_{x\bar{x}} + m_{y\bar{y}}) $ and the baryon analog $ m_{xyz} \gt \dfrac{1}{3}(m_{xxx} + m_{yyy} + m_{zzz}) $ . Hadron mass decomposition validates $ \Delta M_{ \rm{EXP}} \approx \Delta B + \Delta C $ with $ \sigma \sim 2.07 $ MeV for mesons and baryons. Using this decomposition, we obtain approximate mass estimates for unobserved heavy baryons (e.g., $ M(\Omega_{b}^{\ast})\approx 6076.6\, $ MeV, $ M(\Xi_{cc}^{\ast})\approx 3703.6\, $ MeV, and $ M(\Omega_{cc}^{\ast})\approx 3802.4\, $ MeV) and identify favored quark-exchange scattering channels. The present analysis is phenomenological and does not constitute a rigorous three-body derivation.

Wen-Xuan Zhang

Wen-Nian Liu

Duojie Jia

Mass relations in heavy hadrons from Jensen-like inequalities * Duojie Jia is supported by the National Natural Science Foundation of China (12165017)

We postulate that the excesses of di-dijet events observed at the LHC are attributed to the production of four fourth-generation quarks $$b'$$ with a mass $$m_{b'}\approx 2$$ TeV at few-TeV scales. The di-dijet signals around the four-jet invariant mass $$m_{4j}\approx 8$$ TeV arise from a resonant $$b'b'\bar{b}'\bar{b}'$$ tetraquark production, where the dijet resonances of masses about 2 TeV correspond to $$b'\bar{b}'$$ first excited states (color-octet scalars with the principal quantum number $$n=2$$ ) in a Yukawa potential created by Higgs boson exchanges. Those around $$m_{4j}\approx 3.6$$ TeV originate from a non-resonant $$b'b'\bar{b}'\bar{b}'$$ production, where the dijet resonances of masses 0.95 TeV correspond to $$b'\bar{b}'$$ ground states (color-octet vectors with $$n=1$$ ). It is shown that a $$b'\bar{b}'$$ system with $$m_{b'}\approx 2$$ TeV in the Yukawa potential does generate the aforementioned bound state spectrum. We then illustrate that the observed excesses can be accommodated in our setup by translating the fourth-generation model to the effective theories containing color-octet scalars and vectors available in the literature. Simply speaking, our scenario can be viewed as a TeV-scale analogue of the search for a fully charmed tetraquark via the four-muon channels $$X(6900)\rightarrow (c\bar{c})(c\bar{c})\rightarrow 4\mu $$ at a GeV scale.

Hsiang-nan Li

LHC di-dijet excesses as signals of fourth-generation tetraquarks

We compute the leading order modification to the quark–antiquark–<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>-boson vertex in the presence of a constant and uniform magnetic field, specifically for the case where the quark and antiquark are the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>u</mi></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>d</mi><mo stretchy="false">¯</mo></mover></math>, respectively. We find the selection rules for transitions where the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>u</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mover accent="true"><mi>d</mi><mo stretchy="false">¯</mo></mover></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> boson occupy arbitrary Landau levels. We show that, for the particular case where the initial particles each occupy the lowest Landau level, the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>W</mi><mo>+</mo></msup></math> is also produced in the lowest Landau level with a single polarization aligned with the magnetic field. We also illustrate the general findings by computing the case of transitions between low-lying Landau levels and show the correspondence between the polarization vectors for the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math> boson and the polarization states for the quark and the antiquark.

Mexico

Alejandro Ayala

Brazil

Alejandro López

Ana Julia Mizher

Manuel Emiliano Monreal Cancino

Argentina

Norberto Scoccola

Leading order quark–antiquark–<math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>W</mi></math>-boson vertex in the presence of a magnetic field

The concept of prominence is familiar to signal engineers, topographers and mountaineers. We introduce Prominence <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">P</mi></math> as a discriminator of gravitational wave (GW) signals. We treat black hole and neutron star binaries as astrophysical background sources, and show how <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">P</mi></math> can be used to distinguish between GW spectra produced by first-order phase transitions, domain walls and cosmic strings, and combinations thereof. Prominence can also be used to discriminate between these and off-piste sources of GWs. The uncertainty in the measured energy density in GWs at pulsar timing arrays needs to be at the subpercent to percent level for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">P</mi></math> to achieve discrimination at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mn>3</mn><mi>σ</mi></mrow></math>. LISA and ET data are expected to have sufficiently small uncertainties that Prominence can play a central role in their analysis. We define and apply a <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>χ</mi><mn>2</mn></msup></math> statistic based on an inner product in signal space to show that sources indistinguishable at <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>2</mn><mi>σ</mi></math> using the signal-to-noise ratio can be distinguished using <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">P</mi></math> with significances above and in some cases far above <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mn>3</mn><mi>σ</mi></math>.

Portugal

João Gonçalves

United States

Danny Marfatia

António P. Morais

Prominence as a discriminator of gravitational wave signals

In the present work, we study the radiative decays of the <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mo>*</mo></msup></math> molecular state <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mn>0</mn></msub></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>I</mi><mi>G</mi></msup><mo stretchy="false">(</mo><msup><mi>J</mi><mrow><mi>P</mi><mi>C</mi></mrow></msup><mo stretchy="false">)</mo><mo>=</mo><msup><mn>0</mn><mo>+</mo></msup><mo stretchy="false">(</mo><msup><mn>0</mn><mrow><mo>−</mo><mo>+</mo></mrow></msup><mo stretchy="false">)</mo></math> using a phenomenological Lagrangian approach. The molecular coupling is fixed by the compositeness condition with a Gaussian form factor. The partial widths for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>γ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msub><mi>h</mi><mi>c</mi></msub></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ρ</mi></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ω</mi></math> are evaluated. Our results show that the two-photon and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><msub><mi>h</mi><mi>c</mi></msub></math> channels are highly suppressed, while <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo></math>, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ρ</mi></math> are of the order of a few keV, and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>γ</mi><mi>ω</mi></math> reaches several tens of keV, making it the dominant radiative mode. The ratios <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>ψ</mi><mo stretchy="false">(</mo><mn>2</mn><mi>S</mi><mo stretchy="false">)</mo><mo stretchy="false">)</mo><mo>/</mo><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">)</mo></math> and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>ω</mi><mo stretchy="false">)</mo><mo>/</mo><mi mathvariant="normal">Γ</mi><mo stretchy="false">(</mo><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>ρ</mi><mo stretchy="false">)</mo></math> are predicted to be 1–2.6 and 3.4–5.4, respectively, with mild parameter dependence. We also compare with hadronic decays and find that the total radiative decay width is lower than the hadronic decay widths by about one order of magnitude. We propose searching for <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msub><mi>G</mi><mn>0</mn></msub></math> in the sequential decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>Y</mi><mo stretchy="false">(</mo><mn>4230</mn><mo stretchy="false">)</mo><mo stretchy="false">→</mo><mi>γ</mi><msub><mi>G</mi><mn>0</mn></msub><mo stretchy="false">→</mo><mi>γ</mi><mi>ω</mi><mi>J</mi><mo>/</mo><mi>ψ</mi></math>, which is accessible to further experimental measurements by the BESIII, Belle II, and LHCb Collaborations.

Qi Wu

Ming-Qi Cui

Zi-Li Yue

Dian-Yong Chen

Shi-Dong Liu

Gang Li

Radiative decays of the predicted <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>P</mi></math>-wave <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>D</mi><msup><mover accent="true"><mi>D</mi><mo stretchy="false">¯</mo></mover><mo>*</mo></msup></math> molecular state: The <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mn>0</mn><mrow><mo>−</mo><mo>+</mo></mrow></msup></math> case

Since all the Standard Model (SM) parameters have been measured to precision at the percent level or smaller, one would aim to have a framework which describes baryogenesis as precise as possible, where the measured SM parameters are used as inputs. At high temperature before the electroweak symmetry breaking, the SM contains 15 approximate <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><mi>U</mi><mo stretchy="false">(</mo><mn>1</mn><mo stretchy="false">)</mo></mrow></math> symmetries with the associated flavor charges. To describe the evolutions of these flavor charges in a flavor-basis-covariant manner such that physical observables are flavor-basis-independent, a total of five density matrices in flavor spaces are required: three for quarks and two for leptons. Taking into account the quantum chromodynamics and electroweak sphaleron interactions together with all the Yukawa interactions, we obtain the complete flavor-covariant Boltzmann equations. By imposing chemical equilibrium in the lepton sector, we further derive a new effective quark-flavor-covariant formalism which can be used when baryogenesis occurs through number asymmetry generation in the quark sector. To verify the consistency of this complete formalism, we first apply it to leptogenesis scenarios, reproducing previous results which utilize the effective lepton-flavor-covariant formalism up to small corrections due to the quark chemical equilibrium approximations used in the latter formalism. Then, for the first time, we apply the complete formalism as well as the effective quark-flavor-covariant formalism to a cloistered baryogenesis scenario where number asymmetries are generated in the quark sector, showcasing the good agreement between the results from the two formalisms. Finally, we release the first generic baryogenesis public code boleh (BaryOn and Lepton charge Evolution in the Hot big bang) where all the SM interactions are taken into account.

Chee Sheng Fong

Sergio Manuel Cubides Pérez

Cosmic evolution of the standard model flavor charges

Based on <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo stretchy="false">(</mo><mn>10.087</mn><mo>±</mo><mn>0.044</mn><mo stretchy="false">)</mo><mo>×</mo><msup><mn>10</mn><mn>9</mn></msup><mi>J</mi><mo>/</mo><mi>ψ</mi></math> events collected at the center-of-mass energy <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msqrt><mi>s</mi></msqrt><mo>=</mo><mn>3.097</mn><mtext> </mtext><mtext> </mtext><mi>GeV</mi></math> with the BESIII detector, we search for the charged lepton flavor violating decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>±</mo></msup><msup><mi>μ</mi><mo>∓</mo></msup></math> through the process <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>J</mi><mo>/</mo><mi>ψ</mi><mo stretchy="false">→</mo><mi>γ</mi><msup><mi>η</mi><mo>′</mo></msup></math> with <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><msup><mi>η</mi><mo>′</mo></msup><mo stretchy="false">→</mo><msup><mi>π</mi><mo>+</mo></msup><msup><mi>π</mi><mo>−</mo></msup><mi>η</mi></math>. No signal is observed, and an upper limit on the branching fraction is determined to be <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi mathvariant="script">B</mi><mo stretchy="false">(</mo><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>±</mo></msup><msup><mi>μ</mi><mo>∓</mo></msup><mo stretchy="false">)</mo><mo>&lt;</mo><mn>6.8</mn><mo>×</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>7</mn></mrow></msup></math> at the 90% confidence level. This result improves the previous best limit by one order of magnitude.

M. Ablikim

Russia

M.N. Achasov

Sweden

P. Adlarson

X.C. Ai

Italy

C.S. Akondi

Germany

R. Aliberti

A. Amoroso

Q. An

Y.H. An

Y. Bai

JINR

O. Bakina

H.R. Bao

X.L. Bao

M. Barbagiovanni

Poland

V. Batozskaya

Mongolia

K. Begzsuren

N. Berger

M. Berlowski

M.B. Bertani

D. Bettoni

F. Bianchi

E. Bianco

A. Bortone

I. Boyko

R.A. Briere

A. Brueggemann

D. Cabiati

H. Cai

M.H. Cai

X. Cai

A. Calcaterra

G.F. Cao

N. Cao

Türkiye

S.A. Cetin

X.Y. Chai

J.F. Chang

T.T. Chang

G.R. Che

Y.Z. Che

C.H. Chen

Chao Chen

G. Chen

H.S. Chen

H.Y. Chen

M.L. Chen

S.J. Chen

S.M. Chen

T. Chen

W. Chen

X.R. Chen

X.T. Chen

X.Y. Chen

Y.B. Chen

Y.Q. Chen

Z.K. Chen

J. Cheng

L.N. Cheng

South Korea

S.K. Choi

X. Chu

G. Cibinetto

F. Cossio

United Kingdom

J. Cottee-Meldrum

H.L. Dai

J.P. Dai

X.C. Dai

A. Dbeyssi

R.E. de Boer

D. Dedovich

C.Q. Deng

Z.Y. Deng

A. Denig

I. Denisenko

M. Destefanis

F. De Mori

E. Di Fiore

X.X. Ding

Y. Ding

Y.X. Ding

Yi. Ding

J. Dong

L.Y. Dong

M.Y. Dong

X. Dong

Z.J. Dong

M.C. Du

S.X. Du

Shaoxu Du

X.L. Du

Y.Q. Du

Y.Y. Duan

Z.H. Duan

P. Egorov

G.F. Fan

J.J. Fan

Y.H. Fan

J. Fang

Jin Fang

S.S. Fang

W.X. Fang

Y.Q. Fang

Search for the charged lepton flavor violating decay <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mi>η</mi><mo stretchy="false">→</mo><msup><mi>e</mi><mo>±</mo></msup><msup><mi>μ</mi><mo>∓</mo></msup></math>