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2023-12 Contents
2023, 47(12): 1-2.
2023- Contents
2023, (12): 1-11.
Cryogenic phonon-detector model with solid argon for detecting dark matter
Yu Liu, Lei Zhang, Yulu Yan, Shin-Ted Lin, Shukui Liu, Jinjun Zhu, Changjian Tang, Haoyang Xing
2023, 47(12): 123001. doi: 10.1088/1674-1137/acfaee
Over the past few years, phonon detectors have emerged as a prevailing technology for detecting low-mass dark matter due to their low thresholds and high resolution. These detectors, which employ either dual-phase detectors combining phonon-light or phonon-electron interactions, have significantly advanced direct dark matter detection efforts. Argon, as a low-background and high-reserve detection medium, has also played a crucial role in this field. Both liquid-argon single-phase detectors and gas-liquid two-phase time projection chambers (TPCs) have contributed substantially to the direct detection of high-mass dark matter. By integrating these distinct detector types, the upper limits of the corresponding mass cross-section in dark matter detection can be lowered. We propose a phonon detector utilizing solid argon as the absorber, which combines the advantages of both aforementioned detector types. However, due to the requirement for an ultra-low temperature environment in the tens of millikelvin (mK) range, experimental investigations of solid argon phonon detector performance are currently constrained by technical limitations. Therefore, the performance analysis of the solid argon phonon detector presented in this study is only based on sapphire phonon detectors. Although there may be discrepancies between this approximation and the actual performance, the intrinsic characteristics of phonon detectors permit a qualitative evaluation of the solid argon phonon detector's potential capabilities.
Measurement of the effective weak mixing angle at the CEPC
Zhenyu Zhao, Siqi Yang, Manqi Ruan, Minghui Liu, Liang Han
2023, 47(12): 123002. doi: 10.1088/1674-1137/acf91f
We present a study of the measurement of the effective weak mixing angle parameter (\begin{document}$ {\sin^2\theta_{\text{eff}}^{{ \ell }}} $\end{document}) at the Circular Electron Positron Collider (CEPC). As a fundamental physics parameter, \begin{document}$ {\sin^2\theta_{\text{eff}}^{{ \ell }}} $\end{document} plays a key role not only in the global test of the standard model electroweak sector, but also in constraining the potential beyond standard model new physics at the high energy frontier. CEPC proposes a two year running period around the Z boson mass pole at high instataneous luminosity, providing a large data sample with \begin{document}$ 4\times 10^{12}~ Z $\end{document} candidates generated in total. It allows a high precision measurement of \begin{document}$ \sin^2\theta^{\ell}_\text{eff} $\end{document} both in the lepton and quark final states, where the uncertainty can be one order of magnitude lower than any previous measurement at the LEP, SLC, Tevatron, and LHC. It will improve the overall precision of the \begin{document}$ \sin^2\theta^\ell_\text{eff} $\end{document} experimental determination to be comparable to the preicision of the theoretical calculation with two-loop radiative corrections, and it will also provide direct comparisons between different final states. In this paper, we also study the measurement of \begin{document}$ {\sin^2\theta_{\text{eff}}^{{ \ell }}} $\end{document} in the high mass region. Taking data for one month, the precision of \begin{document}$ {\sin^2\theta_{\text{eff}}^{{ \ell }}} $\end{document} measured at 130 GeV from b quark final state is 0.00010, which will be an important experimental observation on the energy-running effect of \begin{document}$ {\sin^2\theta_{\text{eff}}^{{ \ell }}} $\end{document}.
Molecular states in $ {\boldsymbol{D_s^{(*)+}} \boldsymbol{\Xi_c^{(',*)}}} $ systems
Nijiati Yalikun, Xiang-Kun Dong, Bing-Song Zou
2023, 47(12): 123101. doi: 10.1088/1674-1137/acf65e
The possible hadronic molecules in \begin{document}$ D_s^{(*)+}\Xi_c^{(',*)} $\end{document} systems with \begin{document}$ J^P=1/2^-,3/2^- $\end{document}, and \begin{document}$ 5/2^- $\end{document} are investigated with interactions described by light meson exchanges. By varying the cutoff in a phenomenologically reasonable range of \begin{document}$1- 2.5$\end{document} GeV, we find ten near-threshold (bound or virtual) states in the single-channel case. After introducing the coupled-channel dynamics of \begin{document}$ D_s^{+}\Xi_c $\end{document}-\begin{document}$ D_s^{+}\Xi_c^{'} $\end{document}-\begin{document}$ D_s^{*+}\Xi_c $\end{document}-\begin{document}$ D_s^{+}\Xi_c^{*} $\end{document}-\begin{document}$ D_s^{*+}\Xi_c^{'} $\end{document}-\begin{document}$ D_s^{*+}\Xi_c^{*} $\end{document} systems, these states, except those below the lowest channels in each \begin{document}$ J^{P} $\end{document} sector, move into the complex energy plane and become resonances in the mass range \begin{document}$4.43-4.76$\end{document} GeV. Their spin-parities and nearby thresholds are \begin{document}$ 1/2^-(D_s^{+}\Xi_c) $\end{document}, \begin{document}$ 1/2^-(D_s^{+}\Xi_c^{'}) $\end{document}, \begin{document}$ 1/2^-(D_s^{*+}\Xi_c) $\end{document}, \begin{document}$ 1/2^-(D_s^{*+}\Xi_c^{'}) $\end{document}, \begin{document}$ 1/2^-(D_s^{*+}\Xi_c^{*}) $\end{document}, \begin{document}$ 3/2^-(D_s^{*+}\Xi_c) $\end{document}, \begin{document}$ 3/2^-(D_s^{+}\Xi_c) $\end{document}, \begin{document}$ 3/2^-(D_s^{*+}\Xi_c^{'}) $\end{document}, \begin{document}$ 3/2^-(D_s^{*+}\Xi_c^{*}) $\end{document}, and \begin{document}$ 5/2^-(D_s^{*+}\Xi_c^{*}) $\end{document}. The impact of the \begin{document}$ \delta({{\boldsymbol{ r }}}) $\end{document}-term in the one-boson-exchange model on these states is presented. Setting \begin{document}$ \Lambda=1.5 $\end{document} GeV as an illustrative value, it is found that \begin{document}$ 1/2^-(D_s^{+}\Xi_c) $\end{document} is a stable bound state (becoming unstable if the coupling to lower channels is turned on), \begin{document}$ 1/2^-(D_s^{*+}\Xi_c) $\end{document} and \begin{document}$ 3/2^-(D_s^{*+}\Xi_c) $\end{document} are physical resonances in cases where the \begin{document}$ \delta({{\boldsymbol{ r }}}) $\end{document}-term is included or excluded, and the other seven states are physical resonances or "virtual-state-like" poles near thresholds, depending on whether the \begin{document}$ \delta({{\boldsymbol{ r }}}) $\end{document}-term is included. In addition, the partial decay widths of the physical resonances are provided. These double-charm hidden-strangeness pentaquark states, as the partners of the experimentally observed \begin{document}$ P_c $\end{document} and \begin{document}$ P_{cs} $\end{document} states, can be searched for in the \begin{document}$ D^{(*)}\Lambda_c $\end{document} final states in the future.
Light Higgs boson in the NMSSM confronted with the CMS di-photon and di-tau excesses
Weichao Li, Haoxue Qiao, Jingya Zhu
2023, 47(12): 123102. doi: 10.1088/1674-1137/acfaf1
In 2018, the CMS collaboration reported a di-photon excess at approximately 95.3 GeV with a local significance of 2.8 σ. Interestingly, the CMS collaboration also recently reported a di-tau excess at \begin{document}$95- 100$\end{document} GeV with a local significance of \begin{document}$ 2.6- 3.1 \; \sigma $\end{document}. In addition, a \begin{document}$ b\bar{b} $\end{document} excess at 98 GeV with a local significance of 2.3 σ was reported from LEP data approximately twenty years ago. In this study, we addressed the interpretation of these excesses together with a light Higgs boson in the next-to-minimal supersymmetric standard model (NMSSM). We conclude that, in the NMSSM, the \begin{document}$ 95- 100 $\end{document} GeV excesses are difficult to be satisfied simultaneously (not possible globally at the \begin{document}$ 1\sigma $\end{document} level or simultaneously at the \begin{document}$ 2\sigma $\end{document} level). We analyzed two partially-satisfied scenarios: global \begin{document}$ 2\sigma $\end{document} and small di-photon. An approximate equation of global fit to the three excesses was derived, and two representative types of surviving samples were analyzed in detail. Given that the mass regions of these excesses are near the Z boson, we also checked the light Higgs boson in the \begin{document}$ t\bar{t} $\end{document}-associated channels. The detailed results may be useful for further checking the low-mass-region excesses in the future.
(Pseudo) Scalar mesons in a self-consistent NJL model
Xiaozhu Yu, Xinyang Wang
2023, 47(12): 123103. doi: 10.1088/1674-1137/ad0111
In this study, we investigate the mass spectra of π and σ mesons at finite chemical potential using the self-consistent NJL model and the Fierz-transformed interaction Lagrangian. The model introduces an arbitrary parameter α to reflect the weights of the Fierz-transformed interaction channels. We show that, when α exceeds a certain threshold value, the chiral phase transition transforms from a first-order one to a smooth crossover, which is evident from the behaviors of the chiral condensates and meson masses. Additionally, at a high chemical potential, the smaller the value of α, the higher the masses of the π and σ mesons. Moreover, the Mott and dissociation chemical potentials increase with the increase in α. Thus, the meson mass emerges as a valuable experimental observable for determining the value of α and investigating the properties of the chiral phase transition in dense QCD matter.
Quantum calculation of axion-photon transition in electromagnetodynamics for cavity haloscope
Tong Li, Rui-Jia Zhang
2023, 47(12): 123104. doi: 10.1088/1674-1137/ad0620
The Witten effect implies the presence of electric charge of magnetic monople and the possible relationship between axion and dyon. The axion-dyon dynamics can be reliably built based on the quantum electromagnetodynamics (QEMD) which was developed by Schwinger and Zwanziger in the 1960's. A generic low-energy axion-photon effective field theory can also be realized in the language of “generalized symmetries” with higher-form symmetries and background gauge fields. In this work, we implement the quantum calculation of the axion-single photon transition rate inside a homogeneous electromagnetic field in terms of the new axion interaction Hamiltonian in QEMD. This quantum calculation can clearly imply the enhancement of conversion rate through resonant cavity in axion haloscope experiments. We also show the promising potentials on the cavity search of new axion-photon couplings.
Measurement and analysis of the neutron-induced total cross-sections of 209Bi from 0.3 eV to 20 MeV on the Back-n at CSNS
Jieming Xue, Song Feng, Yonghao Chen, Han Yi, Xinxiang Li, Min Xiao, Pinjing Cheng, Rong Liu, Yiwei Yang, Zijie Han, Dajun Zhao, Haoqiang Wang, Baoqian Li, Jirong Zhao, Zijun Liu, Chaomin Chen, Wen Luo, Bo Zheng
2023, 47(12): 124001. doi: 10.1088/1674-1137/acf920
The neutron-induced total cross-section of 209Bi is crucial for the physical design and safety assessment of lead-based fast reactors, and the quality of experimental data should be improved for evaluation and application. A recent experiment was conducted on the back-streaming white neutron beamline (Back-n) at the China Spallation Neutron Source (CSNS) using the neutron total cross-section spectrometer (NTOX). The neutron energy was determined using a fast multi-cell fission chamber and the time-of-flight technique. Two high-purity bismuth samples, 6 mm and 20 mm in thickness, were chosen for neutron transmission measurements and comparisons. The neutron total cross-sections of 209Bi, ranging from 0.3 eV to 20 MeV, were derived considering neutron flight time determination, flight path calibration, and background subtraction. A comparison of the experimental results with the data in the ENDF/B-VIII.0 library showed fair agreement, and the point-wise cross-sections were found to be consistent with existing experimental data. Special attention was given to the determination of resonance parameters, which were analyzed using the R-matrix code SAMMY and Bayesian method in the 0.5 keV to 20 keV energy range. The extracted resonance parameters were compared to previously reported results and evaluated data. This study is recognized as the first one where the neutron total cross-section of bismuth across such a broad energy spectrum is measured in a single measurement or experiment, and it provides valuable data for the assessment of related reaction information for evaluated libraries and the advancement of lead-bismuth-based nuclear systems.
Isomeric pair 95m,g Nb in the photonuclear reactions on natMo at the bremsstrahlung end-point energy of 38–93 MeV
I.S. Timchenko, O.S. Deiev, S.M. Olejnik, S.M. Potin, V.A. Kushnir, V.V. Mytrochenko, S.A. Perezhogin, V.A. Bocharov
2023, 47(12): 124002. doi: 10.1088/1674-1137/acfaed
The \begin{document}${^{\rm{nat}}{\rm{Mo}}}(\gamma,x{{{np}}})^{95{{m,g}}}{\rm{Nb}}$\end{document} photonuclear reaction was studied using the electron beam from the NSC KIPT linear accelerator LUE-40. The experiment was performed using the activation and off-line γ-ray spectrometric technique. The experimental isomeric yield ratio (IR) was determined for the reaction products \begin{document}$^{95{{m,g}}}{\rm{Nb}}$\end{document} at the bremsstrahlung end-point energy \begin{document}$ E_{\rm{\gamma max}} $\end{document} range of 38–93 MeV. The obtained values of IR are in satisfactory agreement with the results of other studies and extend the range of previously known data. The theoretical values of the yields \begin{document}$Y_{{{m,g}}}(E_{\rm{\gamma max}})$\end{document} and the IR for the isomeric pair \begin{document}$^{95{{m,g}}}{\rm{Nb}}$\end{document} from the \begin{document}${^{\rm{nat}}{\rm{Mo}}}(\gamma,x{{{np}}})$\end{document} reaction were calculated using the partial cross-sections \begin{document}$ \sigma(E) $\end{document} from the TALYS1.95 code for six different level density models. For the investigated range of \begin{document}$ E_{\rm{\gamma max}} $\end{document}, the theoretical dependence of IR on energy was confirmed – the IR smoothly increases with increasing energy. The comparison showed a noticeable difference (more than 3.85 times) in the experimental IR relative to all theoretical estimates.
Ab initio calculations of mirror energy difference in sd-shell nuclei
Hong-Hui Li, Jian-Guo Li, Meng-Ran Xie, Wei Zuo
2023, 47(12): 124101. doi: 10.1088/1674-1137/acf035
Mirror energy difference is a key observable in isospin symmetry breaking, containing rich information about nuclear structure. Understanding the mechanisms underlying mirror energy difference is important in nuclear physics. In the present work, we extensively investigated mirror energy difference using ab initio valence-space in-medium similarity renormalization group approach, focusing specifically on \begin{document}$ sd $\end{document}-shell nuclei. The low-lying spectra of Al isotopes and \begin{document}$ N=8 $\end{document} isotones, together with their mirror nuclei, were calculated, followed by a systematic analysis of the evolution of the mirror energy difference. The results suggest that the large mirror energy difference is mainly caused by the weakly-bound effects and large average occupations of the \begin{document}$ 1s_{1/2} $\end{document} orbit. Lastly, we compare the results of our ab initio calculations with shell model results, elucidating the relationship and coherence between these two models.
Bayesian evaluation of energy dependent neutron induced fission yields
Ming-Xiang Xiao, Xiao-Jun Bao, Zheng Wei, Ze-En Yao
2023, 47(12): 124102. doi: 10.1088/1674-1137/acf7b5
From both the fundamental and applied perspectives, fragment mass distributions are important observables of fission. We apply the Bayesian neural network (BNN) approach to learn the existing neutron induced fission yields and predict unknowns with uncertainty quantification. Comparing the predicted results with experimental data, the BNN evaluation results are found to be satisfactory for the distribution positions and energy dependencies of fission yields. Predictions are made for the fragment mass distributions of several actinides, which may be useful for future experiments.
Density-dependent relativistic mean field approach and its application to single-Λ hypernuclei in oxygen hyperisotopes
Shi-Yuan Ding, Wei Yang, Bao-Yuan Sun
2023, 47(12): 124103. doi: 10.1088/1674-1137/acf91e
The in-medium feature of nuclear force, which includes both nucleon-nucleon (\begin{document}$NN$\end{document}) and hyperon-nucleon (\begin{document}$\Lambda N$\end{document}) interactions, impacts the description of single-Λ hypernuclei. With the alternated mass number or isospin of hypernuclei, such effects may be unveiled by analyzing the systematic evolution of the bulk and single-particle properties. From a density-dependent meson-nucleon/hyperon coupling perspective, a new \begin{document}$\Lambda N$\end{document} effective interaction in the covariant density functional (CDF) theory, namely, DD-LZ1-\begin{document}$\Lambda 1$\end{document}, is obtained by fitting the experimental data of Λ separation energies for several single-Λ hypernuclei. It is then used to study the structure and transition properties of single-Λ hypernuclei in oxygen hyperisotopes, in comparison with those determined using several selected CDF Lagrangians. A discrepancy is explicitly observed in the isospin evolution of \begin{document}$\Lambda 1p$\end{document} spin-orbit splitting with various effective interactions, which is attributed to the divergence of the meson-hyperon coupling strengths with increasing density. In particular, the density-dependent CDFs introduce an extra contribution to reduce the value but enhance the isospin dependence of the splitting, which originates from the rearrangement terms of Λ self-energies. In addition, the characteristics of hypernuclear radii are studied along the isotopic chain. Owing to the impurity effect of the Λ hyperon, a size shrinkage is observed in the matter radii of hypernuclei compared with the cores of normal nuclei, and its magnitude is further elucidated to correlate with the incompressibility of nuclear matter. Moreover, there is a sizable model-dependent trend in which the Λ hyperon radii evolve with neutron number, which is decided partly by the in-medium \begin{document}$NN$\end{document} interactions and core polarization effects.
Systematic extraction of the strong absorption distance and Coulomb barrier from elastic scattering
Yun Yang, Pei-Wei Wen, Cheng-Jian Lin, Hui-Ming Jia, Lei Yang, Nan-Ru Ma, Feng Yang, Tian-Peng Luo, Teng-Huan Mo, Chang Chang, Hai-Rui Duan, Ming-Hao Zhang, Zhi-Jie Huang, Cheng Yin
2023, 47(12): 124104. doi: 10.1088/1674-1137/acf7b8
The reduced strong absorption distance \begin{document}$ d_\mathrm{S} $\end{document} and Coulomb barrier height \begin{document}$ V_\mathrm{B} $\end{document} are extracted from the quarter-point recipe from a series of experimental elastic scattering angle distributions. The nuclei with different binding energies are systematically studied as the projectile, including the tightly bound, weakly bound, and halo nuclei. It is found that the mean \begin{document}$ d_\mathrm{S} $\end{document} for halo nuclei is significantly larger than that of tightly and weakly bound nuclei. The complex behavior of \begin{document}$ d_\mathrm{S} $\end{document} regarding the binding energy and properties of the target is observed for halo nuclei. The linear relationship of the reduced distance with system size may be used to estimate the Coulomb barrier radius \begin{document}$ R_\mathrm{B} $\end{document}, which is difficult to obtain from fusion reactions. The rule of \begin{document}$ V_\mathrm{B} $\end{document} concerning the Coulomb parameter z is in agreement with other theoretical barrier laws extracted from the fusion reaction. Furthermore, the reason why the binding energy or deformation has little effect on the linear relationship of \begin{document}$ V_\mathrm{B} $\end{document} as a function of z is clarified.
Evaporation residue cross sections of superheavy nuclei based on optimized nuclear data
Jia-Xing Li, Hong-Fei Zhang
2023, 47(12): 124105. doi: 10.1088/1674-1137/ad021f
This study proposes an optimized method for estimating atomic nucleus masses by combining the finite-range droplet model (FRDM) with the support vector machine algorithm. The optimization process significantly improves the accuracy of the FRDM by reducing the root mean square error from 0.606 to 0.253 MeV. The optimized mass data obtained from this method are then used to calculate the evaporation residue cross-sections (ERCSs) for fusion-evaporation reactions, employing the di-nuclear system model. The experimental results for the 48Ca+238U reaction are relatively well reproduced using these optimized mass data. Additionally, the study investigates the impact of mass uncertainties on fusion and survival probabilities. By considering the mass uncertainties, the ERCSs for new elements 119 and 120 are predicted based on the obtained optimized mass data.
Consistency of Pantheon+ supernovae with a large-scale isotropic universe
Li Tang, Hai-Nan Lin, Liang Liu, Xin Li
2023, 47(12): 125101. doi: 10.1088/1674-1137/acfaf0
We investigate the possible anisotropy of the universe using data on the most up-to-date type Ia supernovae, i.e., the Pantheon+ compilation. We fit the full Pantheon+ data with the dipole-modulated ΛCDM model and find that the data are well consistent with a null dipole. We further divide the full sample into several subsamples with different high-redshift cutoffs \begin{document}$z_c$\end{document}. It is shown that the dipole appears at the \begin{document}$2\sigma$\end{document} confidence level only if \begin{document}$z_c\leq 0.1$\end{document}, and in this redshift region, the dipole is very stable, almost independent of the specific value of \begin{document}$z_c$\end{document}. For \begin{document}$z_c=0.1$\end{document}, the dipole amplitude is \begin{document}$D=1.0_{-0.4}^{+0.4}\times 10^{-3}$\end{document}, pointing toward \begin{document}$(l,b)=(334.5_{\ -21.6^{\circ}}^{\circ +25.7^{\circ}},16.0_{\ -16.8^{\circ}}^{\circ +27.1^{\circ}})$\end{document}, which is approximately \begin{document}$65^{\circ}$\end{document} away from the CMB dipole. This implies that the full Pantheon+ sample is consistent with a large-scale isotropic universe, but the low-redshift anisotropy could not be purely explained by the peculiar motion of the local universe.
Analytical approximate solutions of AdS black holes in Einstein-Weyl-scalar gravity
Ming Zhang, Sheng-Yuan Li, De-Cheng Zou, Chao-Ming Zhang
2023, 47(12): 125102. doi: 10.1088/1674-1137/acfcb0
We consider Einstein-Weyl gravity with a minimally coupled scalar field in four dimensional spacetime. Using the minimal geometric deformation (MGD) approach, we split the highly nonlinear coupled field equations into two subsystems that describe the background geometry and scalar field source, respectively. By considering the Schwarzschild-AdS metric as background geometry, we derive analytical approximate solutions of the scalar field and deformation metric functions using the homotopy analysis method (HAM), providing their analytical approximations to fourth order. Moreover, we discuss the accuracy of the analytical approximations, showing they are sufficiently accurate throughout the exterior spacetime.
Quasinormal modes of Bardeen black holes with a cloud of strings
Yunlong Liu, Xiangdong Zhang
2023, 47(12): 125103. doi: 10.1088/1674-1137/acf3d5
We investigate the quasinormal mode and greybody factor of Bardeen black holes with a cloud of strings via the WKB approximation and verify them using the Prony algorithm. We find that the imaginary part of the quasinormal mode spectra is always negative, and the perturbation does not increase with time, indicating that the system is stable under scalar field perturbation. Moreover, the string parameter a has a dramatic impact on the frequency and decay rate of the waveforms. In addition, the greybody factor increases when a and λ increase and when q and l decrease. The parameters λ and l have a significant effect on the tails. In particular, when \begin{document}$ l=0 $\end{document}, a de Sitter phase appears at the tail.
Slow-roll inflation in ${\boldsymbol f(T,\mathcal{T})} $ modified gravity
Aaqid Bhat, Sanjay Mandal, P.K. Sahoo
2023, 47(12): 125104. doi: 10.1088/1674-1137/ad010f
In this study, we explore the concept of cosmological inflation within the framework of the \begin{document}$ f (T,\mathcal{T}) $\end{document}theory of gravity, where f is a general function of the torsion scalar T and the trace \begin{document}$ \mathcal{T} $\end{document} of the energy-momentum tensor. It is assumed that the conditions of slow-roll inflation are applicable in \begin{document}$ f (T,\mathcal{T}) $\end{document} gravity. To determine different observables related to inflation, such as the tensor-to-scalar ratio r, scalar spectral index \begin{document}$ n_s $\end{document}, spectral index \begin{document}$ \alpha_s $\end{document}, and tensor spectral index \begin{document}$ n_t $\end{document}, the Hubble slow-roll parameters are utilized for a particular model of \begin{document}$ f (T,\mathcal{T}) $\end{document}. Lastly, an assessment is carried out to determine the feasibility of the models by conducting a numerical analysis of the parameters. The findings indicate that it is feasible to achieve compatibility with the observational measurements of slow-roll parameters by utilizing different values of the free parameters.
Probing light DM via the Migdal effect with spherical proportional counter
Yuchao Gu, Jie Tang, Lei Wu, Bin Zhu
2023, 47(12): 125105. doi: 10.1088/1674-1137/acfaef
Owing to its low electronic noise and flexible target materials, the Spherical Proportional Counter (SPC) with a single electron detection threshold can be utilized to search for sub-GeV dark matter (DM). In this study, we investigate the prospects for light DM direct detection via the DM-nucleus Migdal effect in the DARKSPHERE detector. We consider different DM velocity distributions and momentum-transfer effects. For Xenon and Neon targets, we find that the DM mass \begin{document}$m_{\rm DM}$\end{document} can be probed down to as low as \begin{document}$m_{\rm DM} \sim \mathcal{O}$\end{document}(10) MeV, and the derived bounds on the DM-nucleus scattering cross section \begin{document}$ \bar{\sigma}_{n} $\end{document} are sensitive to the high-velocity tails of the DM velocity distribution, which can be altered by orders of magnitude for the different DM velocity distributions in the region \begin{document}$m_{\rm DM} < 10$\end{document} MeV.
Accretion around a hairy black hole in the framework of gravitational decoupling theory
H. Rehman, G. Abbas
2023, 47(12): 125106. doi: 10.1088/1674-1137/ad010e
We investigate astrophysical accretion onto a static and spherically symmetric hairy black hole within the framework of gravitational decoupling. To achieve this goal, we examine the accretion procedure for several types of perfect fluids, including polytropic fluid and ultra-stiff, ultra-relativistic, radiation, and sub-relativistic isothermal fluids. Moreover, we determine the critical or sonic points for numerous fluid forms that are accreting onto the black hole by utilizing the Hamiltonian dynamical approach. Additionally, the closed form of the solutions are presented for a number of fluids, which are represented in phase diagram curves. We estimate the mass accretion rate of a static and spherically symmetric hairy black hole within the framework of gravitational decoupling. These findings are helpful in constraining the parameters of black holes while physical matter accretes onto the black holes.
Erratum: Corrigendum to "Effect of dark energy models on the energy content of charged and rotating black holes" [Chinese Phys. C, 46 (2022) 015101]
Asia Liaqat, Ibrar Hussain
2023, 47(12): 129001. doi: 10.1088/1674-1137/ad0377
In Liaqat and Hussain (2022) it was proved that the effect of dark energy with \begin{document}$ \omega_{n}=-\dfrac{1}{3} $\end{document}, causes a reduction in the energy content of the quintessential charged-Kerr spacetime. This result needs correction as it is observed that the contribution of dark energy first decreases the total energy of the underlying spacetime for smaller values of radial coordinate r and then increases the energy for comparatively larger values of r.