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.

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.

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.

Just Accepted