Chinese Physics C

Quasinormal modes of massless scalar and electromagnetic perturbations for Euler–Heisenberg black holes surrounded by perfect fluid dark matter

Cheng-Fu Feng, Sheng-Yuan Li, Xufen Zhang, Ming Zhang, De-Cheng Zou, Rui-Hong Yue

Published: , doi: 10.1088/1674-1137/aeb2b5

Abstract:
We investigate the quasinormal modes of massless scalar and electromagnetic perturbations in charged Euler--Heisenberg black holes surrounded by perfect fluid dark matter. The quasinormal frequencies are calculated using the asymptotic iteration method and the sixth-order WKB approximation, and the relative deviations between the two methods are quantitatively analyzed to verify the reliability of the results. The greybody factors for both perturbations are also evaluated within the sixth-order WKB framework. We systematically examine the effects of the black hole charge Q, the nonlinear electrodynamic parameter a, the dark matter parameter λ, and the angular quantum number l on the quasinormal frequencies and greybody factors. We find that these parameters significantly modify the structure of the effective potential barriers and consequently affect the oscillation frequencies, damping rates, and wave transmission and reflection properties of the perturbed fields.

Relativistic Proton-Neutron Quasiparticle-Vibration Coupling Theory with Localized Exchange Terms and Tensor Couplings for Gamow-Teller Resonances and β Decay

L. Guo, Y. F. Niu

Published: , doi: 10.1088/1674-1137/aeb253

Abstract:
We develop a relativistic proton-neutron quasiparticle random-phase approximation (pnQRPA) plus proton-neutron quasiparticle-vibration coupling (pnQPVC) model, based on localized relativistic Hartree-Fock-Bogoliubov theory with the PCF-PK1 density functional. This model incorporates localized exchange terms and tensor couplings. The localized exchange terms enable the residual interaction, particularly the isovector-pseudovector (tPV) channel, to be determined fully self-consistently without any phenomenological adjustment of the tPV coupling strength. We apply the newly developed relativistic pnQPVC model to the Gamow-Teller (GT) strength distributions in

\begin{document}$^{116-134}$\end{document}

Sn and the

\begin{document}$\beta^-$\end{document}

-decay half-lives of neutron-rich Ni and Sn nuclei, as well as the

\begin{document}$N=50$\end{document}

and

\begin{document}$N=82$\end{document}

isotonic chains. Channel analysis at the pnQRPA and pnQPVC levels demonstrates that the isovector-tensor and tPV channels play crucial roles in both the GT response and β-decay half-lives. Beyond pnQRPA, QPVC correlations broaden and redistribute the GT strength, bringing the calculated resonance widths and peak energies into better agreement with experiment. QPVC correlations also substantially reduce the calculated β-decay half-lives, enhancing agreement with the experimental data.

Optimization of the factorization scale in QED Drell-Yan-like processes

Andrej Arbuzov, Uliana Voznaya, Aliaksandr Sadouski

Published: , doi: 10.1088/1674-1137/aead6f

Abstract:
We investigate the dependence of corrections from initial-state radiation in

\begin{document}$ e^+ e^- $\end{document}

-annihilation processes on the choice of factorization scale. Different prescriptions for choosing the factorization scale are analyzed at leading- and next-to-leading-logarithmic accuracy. Comparisons with known complete one- and two-loop results are used to optimize this choice.

Production of superheavy nuclei in collisions of ⁴⁸Ca, ⁵⁰Ti, ⁵¹V and ⁵⁴Cr on actinide nuclei with the Skyrme energy-density functional

Xiao-Jun Chen, Zi-Han Wang, Niu Wan, Ming-Hui Huang, Zhao-Qing Feng

Published: , doi: 10.1088/1674-1137/aeac00

Abstract:
Within the framework of the dinuclear system (DNS) model, the synthesis of superheavy nuclei in ⁴⁸Ca-, ⁵⁰Ti-, ⁵¹V-, and ⁵⁴Cr-induced fusion reactions on actinide nuclei has been systematically investigated. The nucleus–nucleus potential and the potential energy surface in the DNS model are calculated using the well-established Skyrme energy-density functional with the parameter sets SKM, SKM*, Ska, Z, and SLy4, respectively. The available experimental data from Dubna, GSI, RIKEN, and Berkeley are well reproduced by the model. It is found that the fusion-evaporation residue excitation functions and production cross sections of superheavy nuclei are correlated with nuclear matter properties. The ⁴⁸Ca-induced reaction, i.e., ⁴⁸Ca + ²⁴⁸Cm, has a larger production cross section for synthesizing the superheavy nucleus livermorium than the non-magic systems ⁵⁰Ti + ²⁴⁴Pu and ⁵⁴Cr + ²³⁸U. The production cross sections of new superheavy elements with atomic numbers

\begin{document}$ Z=119 $\end{document}

and 120 in the reactions ⁵¹V+²⁴⁸Cm and ⁵⁴Cr+²⁴³Am/²⁴⁸Cm are thoroughly investigated. The fusion-evaporation excitation functions strongly depend on the Skyrme parameters, particularly at excitation energies below 40 MeV.

The Extended Ultrahigh-energy Gamma-Ray Emission in the Vicinity of PSR J2238+5903

Zhen Cao, F. Aharonian, Y.X. Bai, Y.W. Bao, D. Bastieri, X.J. Bi, Y.J. Bi, W. Bian, J. Blunier, A.V. Bukevich, C.M. Cai, W.Y. Cao, Zhe Cao, J. Chang, J.F. Chang, E.S. Chen, G.H. Chen, H.K. Chen, L.F. Chen, Liang Chen, Long Chen, M.J. Chen, M.L. Chen, Q.H. Chen, S. Chen, S.H. Chen, S.Z. Chen, T.L. Chen, X.B. Chen, X.J. Chen, X.P. Chen, Y. Chen, N. Cheng, Q.Y. Cheng, Y.D. Cheng, M.Y. Cui, S.W. Cui, X.H. Cui, Y.D. Cui, B.Z. Dai, H.L. Dai, L.X. Dai, Z.G. Dai, , Y.X. Diao, A.J. Dong, X.D. Duan, J.H. Fan, Y.Z. Fan, J. Fang, J.H. Fang, K. Fang, C.F. Feng, H. Feng, L. Feng, S.H. Feng, X.T. Feng, Y. Feng, Y.L. Feng, S. Gabici, B. Gao, Q. Gao, W. Gao, C. Ge, M.M. Ge, T.T. Ge, L.S. Geng, G. Giacinti, G.H. Gong, Q.B. Gou, M.H. Gu, W.M. Gu, F.L. Guo, J. Guo, K.J. Guo, X.L. Guo, Y.Q. Guo, R.P. Han, O.A. Hannuksela, M. Hasan, H.H. He, H.N. He, J.Y. He, X.Y. He, Y. He, S. Hernández-Cadena, C. Hou, X. Hou, H.B. Hu, S.C. Hu, D.H. Huang, F. Huang, J.J. Huang, X.L. Huang, X.T. Huang, X.Y. Huang, Y. Huang, Z.J. Huang, A. Inventa

Published:

Abstract:
We present a comprehensive analysis of the recently discovered TeV gamma-ray source LHAASO J2238+5900. Based on data collected by LHAASO, our fitting results indicate that the source is significantly extended, with an angular extension of

\begin{document}$0.54^{\circ}\pm0.01^{\circ}$\end{document}

, and is spatially coincident with the pulsar PSR J2238+5903. Its spectrum is characterized by a power law with an index of

\begin{document}$\Gamma=1.97\pm0.06$\end{document}

and an exponential cutoff at

\begin{document}$41.0\pm3.5$\end{document}

TeV. In addition, the source exhibits a significant signal of 7.9σ above 100 TeV, implying that it is a PeVatron candidate. Although the gamma-ray emission is consistent with a pulsar wind nebula (PWN) scenario, the relatively large extension also permits a halo interpretation, potentially caused by electron-positron pairs escaping from the PWN.

Decoherence Effects on Primordial Black Holes and Scalar-Induced Gravitational Waves

Waqas Ahmed

Published: , doi: 10.1088/1674-1137/aeabfb

Abstract:
Primordial black holes (PBHs) form when large primordial curvature perturbations re-enter the Hubble radius and exceed the classical collapse threshold. These perturbations originate as quantum fluctuations of the inflationary vacuum, which motivates a quantum-information description of the scalar sector responsible for PBH production. We develop a conservative extension of the standard PBH and scalar-induced gravitational-wave (SIGW) framework, in which Gaussian quantum discord is used as a diagnostic of residual quantum correlations rather than as a new PBH formation criterion. We describe each

\begin{document}$ ({\boldsymbol{k}}, -{\boldsymbol{k}}) $\end{document}

pair as a two-mode Gaussian state and show that, in the pure squeezed limit, discord grows rapidly with the squeezing parameter; consequently, low discord thresholds are automatically satisfied for strongly squeezed modes. The nontrivial regime is the mixed state produced by decoherence. Using a Lindblad open-system description, we motivate a Gaussian loss channel for the scalar covariance matrix and distinguish discord from a covariance-survival factor

\begin{document}$ Q_{{\rm{dec}}}(k) $\end{document}

. If the decoherence channel suppresses the scalar two-point covariance, the PBH abundance can be affected through the classical collapse variance, while the SIGW spectrum is modified more directly by the factors

\begin{document}$ Q_{{\rm{dec}}}(ku)Q_{{\rm{dec}}}(kv) $\end{document}

within the radiation-era convolution. For a narrow scalar peak and slowly varying

\begin{document}$ Q_{{\rm{dec}}} $\end{document}

, this yields the benchmark scaling

\begin{document}$ \Omega_{{\rm{GW}}}^{{\rm{eff}}}\simeq Q_{{\rm{dec}}}^2\Omega_{{\rm{GW}}}^{{\rm{class}}} $\end{document}

. Thus, quantum discord and decoherence provide a controlled way to characterize the quantum-to-classical transition of PBH-producing perturbations, with the clearest imprint appearing in scalar-induced gravitational waves.

Calculation for Electric Dipole Moments of Lepton and Neutron in the N-B-LSSM via the Mass Insertion Approximation

Shuang Di, Wei-Hang Zhang, Rong-Zhi Sun, Xing-Xing Dong, Guo-Zhu Ning, Shu-Min Zhao

Published: , doi: 10.1088/1674-1137/aea8f3

Abstract:
In the N-B-LSSM, we calculate the electric dipole moments (EDMs) of leptons and the neutron at the one-loop level using the Mass Insertion Approximation (MIA). In the Standard Model (SM), charge-parity (CP) violation originates solely from the single phase of the Cabibbo–Kobayashi–Maskawa (CKM) matrix, and the predicted EDMs of leptons and the neutron are well below the current experimental upper limits. Thus, EDMs serve as sensitive probes of CP-violating phases in new physics. The N-B-LSSM extends the Minimal Supersymmetric Standard Model (MSSM) by introducing right-handed neutrino superfields and additional singlet Higgs superfields, thereby enriching the particle spectrum and the sources of CP violation. We derive one-loop analytical expressions for lepton and quark EDMs and show their dependence on model parameters such as

\begin{document}$ g_{YB} $\end{document}

,

\begin{document}$ \theta_{\mu_H} $\end{document}

,

\begin{document}$ \theta_{1'} $\end{document}

,

\begin{document}$ \theta_{BB'} $\end{document}

, and

\begin{document}$ \tan\beta $\end{document}

. Numerical analyses demonstrate that EDM measurements strongly constrain the CP-violating parameter space of the N-B-LSSM and reveal the sensitivity of lepton and neutron EDMs to the extended gauge interactions and supersymmetric parameters. This study provides a systematic theoretical tool and numerical reference for exploring CP violation and new physics within the N-B-LSSM.

Two-loop QCD corrections to CP-even Higgs boson decays into Vγ in the Type-I Two-Higgs-Doublet Model

Lin-Qiao Qu, Zhong-Yuan Liu, Peng-Fei Duan, Yu Zhang, Wei-Long Duan

Published: , doi: 10.1088/1674-1137/aea286

Abstract:
We investigate the QCD corrections to the loop-induced decays of the heavy

\begin{document}$CP$\end{document}

-even Higgs boson,

\begin{document}$H \to V\gamma$\end{document}

(

\begin{document}$V = Z, \gamma$\end{document}

), within the framework of the Type-I Two-Higgs-Doublet Model (THDM). Owing to the similarity of the underlying loop topologies, the two decay channels exhibit closely correlated behavior. After imposing the relevant phenomenological constraints, we evaluate the decay widths for 5000 viable parameter points at next-to-leading order (NLO) in QCD under the alignment limit. The

\begin{document}$H\to\gamma\gamma$\end{document}

width exceeds that of

\begin{document}$H\to Z\gamma$\end{document}

by roughly a factor of four. Both are dominated by the top-quark loop: the W contribution vanishes in the alignment limit, and the charged-Higgs loop is suppressed throughout most of the viable parameter space. The corrections exhibit a pronounced dependence on the heavy Higgs boson mass

\begin{document}$m_H$\end{document}

, reaching a maximum in the vicinity of the

\begin{document}$t\bar{t}$\end{document}

production threshold. To elucidate the individual parameter dependences, dedicated benchmark scenarios are analyzed, revealing that the decay widths decrease monotonically with increasing

\begin{document}$\tan\beta$\end{document}

while increasing with

\begin{document}$m_H$\end{document}

. The QCD corrections for both decay modes typically range from approximately

\begin{document}$-20$\end{document}

% to

\begin{document}$+20$\end{document}

%, with larger corrections in the non-alignment scenario: in the

\begin{document}$H\to\gamma\gamma$\end{document}

channel, they reach up to

\begin{document}$+38$\end{document}

% at large

\begin{document}$\tan\beta$\end{document}

, and in the

\begin{document}$H\to Z\gamma$\end{document}

channel, they cross zero and become positive. The

\begin{document}$CP$\end{document}

selection rule forces the

\begin{document}$t\bar{t}$\end{document}

pair into a P-wave configuration at threshold, which strongly suppresses the Coulomb corrections and ensures the perturbative stability of the fixed-order prediction. A comparison with ATLAS limits shows that current data do not yet constrain the parameter space, whereas the

\begin{document}${\cal{O}}$\end{document}

(15%) NLO corrections may become relevant for interpreting exclusion bounds at the HL-LHC.

Reconstructability and directed flow of short-lived resonances in Au+Au collisions at 19.6 and 200 GeV

Junyi Han, Xialei Jiang, Hongcan Li, Yaping Wang

Published: , doi: 10.1088/1674-1137/aea831

Abstract:
We present a systematic study of the reconstructability and directed flow of short-lived hadronic resonances in Au+Au collisions at

\begin{document}$\sqrt{s_{NN}}=19.6$\end{document}

and

\begin{document}$200$\end{document}

GeV using the UrQMD transport model. The reconstructable fractions of

\begin{document}$\rho^0$\end{document}

,

\begin{document}$K^{*0}$\end{document}

, and

\begin{document}$\Lambda(1520)$\end{document}

are examined as functions of charged-particle multiplicity and resonance lifetime. The results show a clear lifetime-dependent ordering, with shorter-lived resonances exhibiting stronger suppression of reconstructability. The directed-flow analysis reveals clear differences between resonances and their corresponding stable hadrons in mid-central collisions; however, these differences are substantially reduced in peripheral collisions. These results demonstrate that hadronic evolution significantly affects both resonance reconstructability and final-state directed flow, thereby providing complementary probes of the hadronic stage in relativistic heavy-ion collisions.

The new spin-statistics theorem arising from pseudo-Hermiticity

Yao Bai, Cheng-Yang Lee, Ruifeng Leng, Siyi Zhou

Published: , doi: 10.1088/1674-1137/aea547

Abstract:
We prove a new spin–statistics theorem for a class of quantum field theories with pseudo-Hermitian Hamiltonians. Quantum fields with integer spin exhibit fermionic statistics, whereas those with half-integer spin exhibit bosonic statistics, in contrast to the conventional case. This reversal arises from defining canonical field operators using pseudo-Hermitian conjugation rather than Hermitian conjugation, thereby circumventing the conventional spin–statistics theorem. The free fields retain locality, Lorentz covariance, and unitary evolution. However, interactions can violate unitarity because of the intrinsically non-Hermitian nature of pseudo-Hermitian Hamiltonians. We discuss unitarity issues in this quantum field theory and its potential applications to the dS₄/CFT₃ correspondence.

A high performance partial wave analysis framework for hadron spectroscopy

Benhou Xiang, Shuangshi Fang, Beijiang Liu

Published: , doi: 10.1088/1674-1137/aeb254

Abstract:
Partial wave analysis (PWA) is a key method in hadron physics for extracting the properties of hadronic resonances. As experimental statistics increase, conventional implementations face substantial challenges in memory usage and computational speed. We present

\begin{document}$\mathrm{CTPWA} $\end{document}

, a high-performance PWA framework based on the covariant tensor formalism. This framework incorporates extensive precomputation and caching mechanisms, together with fully GPU-based likelihood computation and minimization. These optimizations accelerate fitting by two orders of magnitude relative to autograd-based GPU PWA programs, making high-statistics partial wave analyses feasible in high-precision experiments such as BESIII.

Measurement of $ \Xi^-/\bar{\Xi}^{+} $ production in jets from Z boson decays using DELPHI open data

Zhouyue Fan, Yuzhi Che, Xinchou Lou, 照茹张, Jinfei Wu, Gengyuan Zhang, Gang Li, Yanping Huang, Manqi Ruan

Published: , doi: 10.1088/1674-1137/aea82b

Abstract:
The production rates of

\begin{document}$ \Xi^{-}/\bar{\Xi}^{+} $\end{document}

baryons in energy-ranked jets produced from

\begin{document}$ Z\to{\rm{hadrons}} $\end{document}

decays are measured using

\begin{document}$ 3.2 $\end{document}

million hadronic Z decay events recorded by the DELPHI experiment. Jets are reconstructed using the Durham algorithm with

\begin{document}$ y_{{\rm{cut}}}=0.005 $\end{document}

. Quark- and gluon-enriched jet samples are obtained by ranking the jet energies in three-jet events. The softest jet is found to produce fewer

\begin{document}$ \Xi^{-}/\bar{\Xi}^{+} $\end{document}

and less energetic baryons than the other jets. The ratio of

\begin{document}$ \Xi^{-}/\bar{\Xi}^{+} $\end{document}

production rates in gluon and quark jets, each normalized to the corresponding mean charged-particle multiplicity, is measured to be

\begin{document}$ 1.21 \pm 0.18\; {\rm{(stat.)}} \pm 0.26\; {\rm{(syst.)}} $\end{document}

. This result is consistent with the JETSET expectation and the OPAL measurements of

\begin{document}$ K_S^0 $\end{document}

and Λ productions in Z decays. This study presents the first measurement of the gluon-to-quark production ratio for baryons containing two s quarks, providing new insights into strange-quark production and hadronization. Future

\begin{document}$ e^{+}e^{-} $\end{document}

colliders such as CEPC and FCCee will provide much larger Z-boson samples and enable far more precise studies of the subject.

An algorithm for the symbolic reduction of multi-loop Feynman integrals via generating functions

Bo Feng, Xiang Li, Yuanche Liu, Yanqing Ma, Yang Zhang

Published: , doi: 10.1088/1674-1137/ae8f25

Abstract:
We develop a generating-function formulation for the symbolic reduction of multi-loop Feynman integrals. In this framework, integration-by-parts identities are recast as differential equations for sector-wise generating functions, allowing the reduction problem to be studied within a non-commutative algebra of differential operators rather than solely through relations among individual integrals. This perspective yields an iterative algorithm that generates candidate equations, extracts symbolic reduction rules, updates the active rule set, and verifies completeness on the lattice of integral indices. We illustrate the method using the sunset topology, planar and non-planar massless double-box topologies, representative subsectors, and a degenerate example in which the top sector contains no master integral. Collectively, these examples demonstrate how symbolic reduction rules, descendant equations, and completeness criteria can be organized within a single algebraic framework.

Joint factorization and resummation of the EEC and thrust in e⁺e⁻ collisions

Ming-Jun Liu, Zuo Luan, Ding Yu Shao, Yu-Hang Zhao

Published: , doi: 10.1088/1674-1137/ae9927

Abstract:
We present a joint factorization and resummation study of the energy-energy correlator (EEC) and thrust in

\begin{document}$ e^+e^- $\end{document}

collisions. An analysis of the joint kinematic distribution reveals five relevant regimes that govern how the global event shape constrains local energy correlations. In the collinear limit (

\begin{document}$ z \to 0 $\end{document}

), we show that the global thrust boundary strongly constrains the jet substructure, necessitating a sub-jet refactorization. In the back-to-back limit (

\begin{document}$ z \to 1 $\end{document}

), the coexistence of

\begin{document}$ {\rm{SCET}}_{{\rm{I}}} $\end{document}

and

\begin{document}$ {\rm{SCET}}_{{\rm{II}}} $\end{document}

soft scales requires the

\begin{document}$ {\rm{SCET}}_{+} $\end{document}

framework. We derive the factorization theorems for all five regimes and calculate the corresponding differential jet functions at one-loop order. By cleanly separating the overlapping soft and collinear modes, our framework provides a systematic factorization description of the EEC under global thrust constraints in the singular limits.

Searching for vectorlike T quarks in the T→tZ channel at a future muon-proton collider

Yin-Hao Gao, Yao-Bei Liu

Published: , doi: 10.1088/1674-1137/aea285

Abstract:
We investigate the discovery potential for a singly produced vector-like top quark T in the

\begin{document}$T\to tZ$\end{document}

decay channel at future muon-proton (

\begin{document}$\mu p$\end{document}

) colliders, considering three benchmark center-of-mass energies:

\begin{document}$\sqrt{s}=5.29$\end{document}

,

\begin{document}$6.48$\end{document}

, and

\begin{document}$9.16$\end{document}

TeV. The baseline signal final state consists of a semileptonic top decay

\begin{document}$t\to bW\to b\ell\nu$\end{document}

and a hadronic

\begin{document}$Z\to q\bar{q}$\end{document}

decay, in which the collimated quark pair from the Z boson is reconstructed as a single large-radius fat jet J. Full detector-level Monte Carlo simulations are performed for both the signal process and the dominant Standard Model backgrounds. We derive the

\begin{document}$5\sigma$\end{document}

discovery contours and the

\begin{document}$95\%$\end{document}

confidence-level exclusion limits in the two-dimensional parameter space spanned by the VLQ mass

\begin{document}$m_T$\end{document}

and the effective coupling

\begin{document}$g^*$\end{document}

. A comparison with the

\begin{document}$T\to Wb$\end{document}

channel and with searches at other collider facilities shows that the

\begin{document}$T\to tZ$\end{document}

decay mode provides complementary sensitivity and offers unique advantages for probing high-mass vector-like T quarks in the boosted-jet topology.

Doubly charged Higgs production within the Higgs triplet model at future lepton colliders

Shu-Xiang Li, Ren-You Zhang, Ming-Hui Liu, Xiao-Feng Wang, Zhong-Yuan Liu, Yi Jiang, Liang Han, Qing-hai Wang

Published: , doi: 10.1088/1674-1137/ae9f38

Abstract:
We investigate in detail the discovery potential of the doubly charged Higgs boson at the Compact Linear Collider in

\begin{document}$ e^-e^- $\end{document}

,

\begin{document}$ e^-\gamma $\end{document}

,

\begin{document}$ \gamma\gamma $\end{document}

, and

\begin{document}$ e^+e^- $\end{document}

collision modes within the Higgs triplet model, using two extreme benchmark points as representatives of the Yukawa-like and gauge-like regions. In the Yukawa-like region, the most promising production mechanism is single production in

\begin{document}$ e^-e^- $\end{document}

and

\begin{document}$ e^-\gamma $\end{document}

collisions. Given the subsequent decay of the doubly charged Higgs boson into a same-sign lepton pair, CLIC can achieve a statistical significance well beyond the discovery threshold within the parameter space allowed by experimental constraints. In the gauge-like region, using the

\begin{document}$ \ell^{\pm}\ell^{\pm} + \geq 3j $\end{document}

final state, CLIC exhibits robust discovery potential for the doubly charged Higgs boson up to a mass of approximately

\begin{document}$ 1.2\; \mathrm{TeV} $\end{document}

. We also investigate the search for doubly charged Higgs bosons at the HL-LHC. Our results demonstrate that CLIC offers greater advantages and superior discovery potential for the doubly charged Higgs boson compared with the HL-LHC.

The resonance effect for the CP asymmetry associated with the process ${\boldsymbol\omega{\bf\to}{\boldsymbol\pi}^+{\boldsymbol\pi}^-{\boldsymbol\pi}^{\bf 0} }$

Xi-Liang Yuan, Gang Lü, Na Wang, Chao Wang

Published: , doi: 10.1088/1674-1137/ad8ec2

Abstract:
The direct CP asymmetry in the weak decay process of hadrons is commonly attributed to the weak phase of the CKM matrix and the indeterminate strong phase. We propose a method to generate a significant phase difference through the interference between ρ and ω mesons, taking into account the G-parity allowed decay process of

\begin{document}$\omega \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document}

and the G-parity-suppressed decay process of

\begin{document}$\rho^{0} \rightarrow \pi^{+}\pi^{-}\pi^{0}$\end{document}

in B meson decays. This interference can lead to notable changes in the CP asymmetry within the interference region. Additionally, we calculate the integral results for different phase space regions of the four-body decay process. We hope that our work provides valuable theoretical guidance for future experimental investigations on CP asymmetry in these decays.

Discriminating baryonium and final-state-interaction interpretations of X(2356)

Bing-Dong Wan, Sheng-Qi Zhang

Published: , doi: 10.1088/1674-1137/aeb2b2

Abstract:
We revisit the X(2356) enhancement observed by BESIII in

\begin{document}$ e^+e^-\to\Lambda\bar\Lambda\eta $\end{document}

from the perspective of near-threshold dynamics. Motivated by the possible existence of light

\begin{document}$ \Lambda\bar\Lambda $\end{document}

baryonium, we compare this interpretation with final-state interaction (FSI) explanations within a minimal FSI-dressed pole framework. Fits of pure-FSI, baryonium-like-pole, and mixed pole–continuum scenarios to the digitized BESIII spectrum indicate that the energy-dependent FSI description achieves the best balance between fit quality and model complexity. The extracted pole positions depend strongly on the amplitude parametrization, highlighting the sensitivity of the baryonium interpretation to the treatment of the continuum. We discuss how decay channels, spin observables, and searches for partner states can provide complementary constraints on the dynamics underlying the enhancement.

Unbounded radius of innermost stable circular orbit in higher-dimensional black holes

Hocheol Lee, Bogeun Gwak

Published: , doi: 10.1088/1674-1137/aea8f4

Abstract:
The innermost stable circular orbit (ISCO) provides a fundamental test of spacetime structure. However, the influence of anisotropic energy–momentum tensors on its properties in higher-dimensional black hole spacetimes remains incompletely understood. In this work, we investigate the upper bound on the ISCO radius in higher-dimensional, static, spherically symmetric, and asymptotically flat black hole spacetimes in the presence of an anisotropic energy–momentum tensor. We assume that the energy–momentum tensor satisfies the weak energy condition, has a nonpositive trace, and obeys constraints on the radial and tangential pressures, which are collectively equivalent to the dominant energy condition with additional restrictions. By analyzing the effective potential for timelike geodesics and imposing the ISCO conditions, we demonstrate that, in general, no upper bound exists on the ISCO radius in higher-dimensional spacetimes. The results show that the allowed equations of state of matter at the ISCO depend explicitly on the spacetime dimension. In the large-D limit, both the radial and tangential equations of state vanish, corresponding to pressureless dust behavior. These findings advance our understanding of orbital stability in higher-dimensional gravitational systems and highlight fundamental differences from four-dimensional black hole dynamics.

Quantum correlations of neutrinos in the Kerr-Newman space-time

Ze-Wen Li, Shu-Jun Rong

Published: , doi: 10.1088/1674-1137/aeaa12

Abstract:
Quantum phases establish a connection between gravitation and quantum information, offering a novel avenue for exploring the properties of space-time. In this paper, we investigate the quantum correlations (QCs) of neutrinos in the Kerr-Newman space-time for both zero- and nonzero-angular-momentum propagation. The results show that, for zero-angular-momentum propagation, the oscillation periods of the survival probability and QCs progressively decrease with propagation distance in the inward direction. In the outward direction, increasing M lengthens the oscillation periods of

\begin{document}$P_{\nu_e\rightarrow\nu_e}$\end{document}

, entanglement, and the monogamy of nonlocality, whereas increasing the angular momentum a or charge Q shortens them. For nonzero-angular-momentum propagation, the metric parameters also generate local profile modulations through additional two-path interference terms, rather than merely rescaling the oscillation period. Furthermore, we find that, despite differences in their ranges of variation, entanglement and coherence exhibit highly consistent oscillatory behavior in both propagation cases. These findings provide a comprehensive understanding of neutrino-based relativistic quantum information.

Hawking radiation from non-minimal Einstein–Yang–Mills black holes

Bekir Can Lütfüoğlu, Abubakir Shermatov, Sardor Murodov, Javlon Rayimbaev, Maksud Umaraliyev

Published: , doi: 10.1088/1674-1137/aeaa11

Abstract:
We study Hawking emission from the regular magnetic black hole in non-minimal Einstein–Yang–Mills theory. The geometry is supported by a Wu–Yang charge, whose Yang–Mills field couples directly to curvature through the non-minimal susceptibility tensor. This coupling removes the central singularity. In the quasi-stationary approximation, in which the temperature is fixed during the emission of individual quanta, we compute greybody factors for a real massless scalar, an electromagnetic field, and a neutral massless Dirac test field by direct integration of the corresponding one-dimensional scattering equations. We compare these results with those obtained using the higher-order WKB approach and integrate the resulting Hawking spectra. For a representative fixed charge, increasing the non-minimal coupling changes the greybody thresholds only moderately, whereas the Hawking temperature and particle luminosity are strongly suppressed near extremality. A direct separation of temperature and greybody-factor effects shows that cooling accounts for most of the orders-of-magnitude suppression, although modified low-frequency transmission provides an additional reduction near the endpoint. The photon-plus-light-fermion luminosity decreases by many orders of magnitude near the endpoint, and the residual massless flux becomes increasingly fermion dominated.

Just Accepted