We present an investigation on cosmological implications resulting from spontaneous dark $ S U(2)_d $ symmetry breaking in conjunction with the Witten effect. Furthermore, we examine the mass of hidden monopoles generated by phase transition as well as the impact of axion-monopole interactions on the axion mass. Following spontaneous breaking of the PQ symmetry, axions emitted by cosmic strings or domain walls as well as hidden monopoles generated during this transition may collectively contribute to the observed dark matter relic density. Additionally, the stochastic gravitational wave background generated by sub-GeV phase transitions and by the decay of axionic domain walls formed during sub-ZeV phase transitions could account for the low-frequency gravitational wave signals detected by PTA experiments.

China

Ruiyu Zhou

Ligong Bian

Gravitational waves and dark matter with Witten effect * Supported by the National Key Research and Development Program of China (2021YFC2203004). Ruiyu Zhou is supported by the National Natural Science Foundation of China (12305109, 12147102), Chongqing Natural Science Foundation project (CSTB2022NSCQ-MSX0534), and Science and Technology Research Project of Chongqing Municipal Education Commission (KJQN202300614). Ligong Bian is supported by the National Natural Science Foundation of China (12322505, 12347101). Ligong Bian also acknowledges Chongqing Natural Science Foundation (CSTB2024NSCQ-JQX0022) and Chongqing Talents: Exceptional Young Talents Project (cstc2024ycjhbgzxm0020).

The neutrino floor, a theoretical sensitivity limit for dark matter (DM) direct detection, is being redefined as the boundary of a dynamic ''neutrino fog,'' where neutrino signals become inevitable, obscuring DM detection due to statistical and systematic uncertainties. This study provides the first site-specific analysis of the neutrino floor at China Jinping Underground Laboratory (CJPL), leveraging its unique geographic and environmental characteristics. We quantify how CJPL’s suppressed atmospheric neutrino flux (approximately 30% lower than that of Laboratori Nazionali del Gran Sasso (LNGS)) reshapes the neutrino floor, thereby enabling improved sensitivity to high-mass WIMPs (mass > 10 GeV). Using a gradient-based framework, we derive the CJPL’s neutrino floor and estimate the detection prospects for the PandaX-xT experiment. Our results demonstrate that a 500 tonne-year exposure with PandaX-xT could reach the floor, probing spin independent cross-sections down to $ \sigma_{n}\sim 3\times 10^{-49}\; {\rm{cm}}^2$ at a DM mass of 70 GeV/$\textit{c}$ $^{2}$.

Yingjie Fan

Xuewen Liu

Ning Zhou

Characterizing the CJPL’s site-specific neutrino floor as the neutrino fog boundary * Xuewen Liu is supported by the Project of Shandong Province Higher Educational Science and Technology Program (2022KJ271). Ning Zhou is supported by National Science Foundation of China (12325505)

The projected multidimensionally constrained relativistic Hartree-Bogoliubov model is employed to calculate the potential energy surface of the high-spin states in 56Ni. It is pointed out for the first time that possible octupole deformations exist for the positive and negative parity superdeformed bands in 56Ni, with deformations <math altimg='si1.svg'><msub><mrow><mi>&#946;</mi></mrow><mrow><mn>30</mn></mrow></msub><mo>&#8764;</mo><mn>0.14</mn></math> and <math altimg='si2.svg'><msub><mrow><mi>&#946;</mi></mrow><mrow><mn>30</mn></mrow></msub><mo>&#8764;</mo><mn>0.24</mn></math>, respectively, along with a large prolate deformation of <math altimg='si3.svg'><msub><mrow><mi>&#946;</mi></mrow><mrow><mn>20</mn></mrow></msub><mo>&#8764;</mo><mn>0.42</mn></math>. These octupole deformations are induced by the coupling between <math altimg='si4.svg'><mn>2</mn><msub><mrow><mi>p</mi></mrow><mrow><mn>3</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow></msub></math> and <math altimg='si5.svg'><mn>1</mn><msub><mrow><mi>g</mi></mrow><mrow><mn>9</mn><mo stretchy='false'>/</mo><mn>2</mn></mrow></msub></math> orbits at the deformation <math altimg='si6.svg'><msub><mrow><mi>&#946;</mi></mrow><mrow><mn>20</mn></mrow></msub><mo>&#8764;</mo><mn>0.4</mn></math>. The calculated excitation energies of the two rotational bands are consistent with the observed superdeformed bands of 56Ni. In addition, two rotational bands are predicted, consisting of one superdeformed band with negative parity and one hyperdeformed band with positive parity.

Xiao Lu

Shivani Jain

Japan

Hiroyuki Sagawa

Shan-Gui Zhou

Octupole correlations in superdeformed bands of 56Ni

In this study, we investigate the $R^2$ corrections to the dissociation of heavy quarkonium in the Gauss-Bonnet gravitational background. We analyze the impact of the Gauss-Bonnet parameter $\lambda_{\rm GB}$ on the spectral function of charmonium and bottomonium and examine the effect of $\lambda_{\rm GB}$ on the dissociation of heavy quarkonium. Our results show that $\lambda_{\rm GB}$ reduces the peak height and increases the peak width of the spectral function, suggesting that $\lambda_{\rm GB}$ enhances the dissociation of heavy quarkonium. We also discuss the variation in the dissociation of heavy quarkonium with the ratio of shear viscosity to entropy density and observe that the dissociation is easier in more perfect plasma. Additionally, we observe that the temperature decreases the peak height and widens the peak, thereby accelerating the dissociation.

Zhou-Run Zhu

Manman Sun

Rui Zhou

Jinzhong Han

$\textit{R}$ $^{2}$ corrections to holographic heavy quarkonium dissociation * Rui Zhou supported by the Science and Technology Development Plan Project of Henan Province, China (242102230085), the National Natural Science Foundation of China (12404470), the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023017). Manman Sun supported by the National Natural Science Foundation of China (12305076). Zhou-Run Zhu supported by the High Level Talents Research and Startup Foundation Projects for Doctors of Zhoukou Normal University, China (ZKNUC2023018)

A special class of four-point correlation functions in the maximally supersymmetric Yang-Mills theory is given by the square of the Fredholm determinant of a generalized Bessel kernel. In this note, we re-express its logarithmic derivatives in terms of a two-dimensional Riemann-Hilbert problem. We solve the latter in the null limit making use of the Deift-Zhou steepest descent. We reproduce the exact octagonal anomalous dimension in 't Hooft coupling and provide its novel formulation as the convolution of a non-linear quasiclassical phase with the Fermi distribution in the limit of the infinite chemical potential.

United States

A.V. Belitsky

Null octagon from Deift-Zhou steepest descent

We study the quasi-two-body decays 
					 by employing the perturbative QCD (PQCD) factorization approach, where the charmonia 
					 represents 
					 and 
					. The corresponding decay channels are studied by constructing the kaon-pion distribution amplitude (DA) 
					, which comprises important final state interactions between the kaon and pion in the resonant region. Relativistic Breit-Wigner formulas are adopted to parameterize the time-like form factor 
					 appearing in the kaon-pion DAs. The SU(3) flavor symmetry breaking effect resulting from the mass difference between the kaon and pion is taken into account, which makes significant contributions to the longitudinal polarizations. The observed branching ratios and the polarization fractions of 
					 are accommodated by tuning hadronic parameters for the kaon-pion DAs. The PQCD predictions for 
					 modes from the same set of parameters can be tested by precise data obtained in the future from LHCb and Belle II experiments.
				

Ya Li

Zhou Rui

Zhen-Jun Xiao

P-wave contributions to B(s)→ψKπ decays in perturbative QCD approach Supported by the National Natural Science Foundation of China (11947013, 11605060, 11775117, 11547020); Ya Li is also Supported by the Natural Science Foundation of Jiangsu Province (BK20190508) and the Research Start-up Funding of Nanjing Agricultural University; Zhou Rui is Supported in part by the Natural Science Foundation of Hebei Province (A2019209449)

Pairing correlations play a very important role in atomic nuclei. Although several effective pairing interactions have been used in mean field calculations for nucleons, little is known about effective pairing interactions for hyperons. Based on the quark model, we propose a relationship between effective pairing interactions for hyperons and for nucleons; e.g., for Λs, the strength of the pairing interaction is 4/9 of that for nucleons. A separable pairing force of finite range which has been widely applied to describing pairing correlations in normal nuclei is used to investigate pairing effects in multi-Λ Ca, Sn and Pb hypernuclei.

Yu-Ting Rong

Pengwei Zhao

Strength of pairing interaction for hyperons in multistrangeness hypernuclei

We explore the interplays among the formation of a halo, deformation effects, the inversion of sd states, the shell evolution, and changes of nuclear magicities in $^{22}$C by using a deformed relativistic Hartree–Bogoliubov model in continuum. It is revealed that there is an inversion between the two spherical orbitals <math><mn>2</mn><msub><mrow><mi>s</mi></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msub></math> and <math><mn>1</mn><msub><mrow><mi>d</mi></mrow><mrow><mn>5</mn><mo>/</mo><mn>2</mn></mrow></msub></math> in $^{22}$C compared with the conventional single particle shell structure in stable nuclei. This inversion, together with deformation effects, results in a shrunk halo and a quenched shell gap at <math><mi>N</mi><mo>=</mo><mn>16</mn></math>. It is predicted that the core of $^{22}$C is oblate but the halo is prolate. Therefore several exotic nuclear phenomena, including the halo, the shape decoupling effects, the inversion of sd states, and the evolution of shell structure which results in (dis)appearance of magic numbers, coexist in one single nucleus <math><mmultiscripts><mrow><mi>C</mi></mrow><mprescripts></mprescripts><none></none><mrow><mn>22</mn></mrow></mmultiscripts></math>.

Xiang-Xiang Sun

Jie Zhao

Shrunk halo and quenched shell gap at = 16 in C: Inversion of States and Deformation Effects

We improve our recently proposed unified description for strange quark matter (SQM) objects, in the way that analytical expressions are derived and used to calculate the distribution of particles inside an SQM object. In the improved model, the computational time is greatly reduced without losing accuracy. The properties of SQM objects are then investigated by adopting perturbative quantum chromodynamics (pQCD) with running quark masses and coupling constant. Aside from the increase of masses and radii of strange stars, it is found that the perturbative interactions also make the electric field on the surface stronger and extends deeper into the core, while small SQM objects become less compact and more positively charged. These may affect the experimental searches of SQM.

Cheng-Jun Xia

Stable strange quark matter objects with running masses and coupling constant

In the present paper, the exact solutions of spherically symmetrical Einstein field equations describing wormholes supported by phantom energy that violates the null energy condition from Shan–Chen background fluid are obtained. We have considered the important case of the model parameter ψ≈1 , which corresponds to the “saturation effect”, and this regime corresponds to an effective form of “asymptotic freedom” for the fluids, but occurring at cosmological rather than subnuclear scales. Then we investigate the allowed range for the values of the model parameters g and ω when the spacetime metrics describe wormholes and discuss the possible singularities of the solutions, finding that the obtained spacetimes are geodesically complete. Furthermore, we construct two traversable wormholes through matching our obtained interior solutions to the exterior Schwarzschild solutions and analyze the traversablities of the wormholes. Finally, we consider the case of anisotropic pressure and discover that the transverse pressure also crosses the phantom divide -1 with the growth of the wormhole dimension, and it tends to be the same as the radial pressure with the growth of the wormhole radius.