arXiv subjects

Yu-Feng Zhou

Publications and source records attributed to Yu-Feng Zhou.

At least 19 recordsLinked to original sources

arXiv2026

Neutrino Constraints on memory-burdened Primordial Black Holes from Dwarf Spheroidal Galaxies

Dwarf spheroidal galaxies (dSphs) represent prime targets for indirect dark matter (DM) searches due to their substantial DM content and low astrophysical backgrounds. In this work, we conduct a comprehensive search for neutrino signals originating from memory-burdened primordial black holes (PBHs) as DM candidates, utilizing 10 years of publicly available muon-track data from the IceCube Neutrino Observatory. We systematically compile $\mathcal{D}$-factor measurements from four independent literature sources, resulting in a robust sample of 14 dSphs with well-characterized DM distributions. For each dSph, we perform an unbinned maximum-likelihood analysis to evaluate the significance of potential PBH neutrino emission, incorporating $\mathcal{D}$-factor uncertainties through a profile likelihood framework. No significant excess over the background-only hypothesis is detected. Building upon these null results, we derive upper limits on the PBH abundance fraction, assuming a monochromatic mass distribution. Our analysis demonstrates that constraints obtained in the $k=1$ case exhibit significant improvement compared to previous studies, while the $k=2$ case yields less restrictive limits due to limited sensitivity of IceCube in the relevant energy range. Furthermore, our combined analysis of 14 dSphs achieves substantially enhanced sensitivity, as the independent error treatment effectively reduces statistical uncertainties.

astro-ph.CO↗

arXiv2026

Constraints on Primordial Black Holes from Galactic Diffuse Synchrotron Emissions

We investigate the possibility of constraining primordial black holes (PBHs) with masses $M_\mathrm{PBH}\gtrsim 10^{15}\,\mathrm{g}$ through Galactic diffuse synchrotron emissions. Due to Hawking radiation, these types of PBHs are expected to be stable sources of cosmic-ray (CR) electrons and positrons with energies below $\mathcal{O}(10\,\mathrm{MeV})$. In many CR propagation models with diffusive re-acceleration characterized by a significant Alfvén velocity $V_a\sim \mathcal{O}(10)\,\mathrm{km/s}$, the energies of the evaporated electrons/positrons can be further enhanced to $\mathcal{O}(100)\,\mathrm{MeV}$ through their scattering with the Galactic random magnetic fields. Consequently, the observation of Galactic synchrotron emissions at frequencies above $\sim 20\,\mathrm{MHz}$ can provide useful constraints on the abundance of PBHs. Using the AMS-02 and Voyager-1 data on the boron-to-carbon nuclei flux ratio, we confirm that a significant Alfvén velocity $V_a \sim 20\,\mathrm{km/s}$ is favored in several benchmark diffusive re-acceleration models. We show that, in this scenario, the observed low-frequency synchrotron emissions (from 22 MHz to 1.4 GHz) can provide stringent constraints on PBH abundance. The obtained conservative constraints are stronger than those derived from the Voyager-1 all-electron (electron plus positron) data by more than one order of magnitude for $M_\mathrm{PBH}\gtrsim 1\times 10^{16}\,\mathrm{g}$, and also stronger than our previous constraints derived from the AMS-02 positron data for $M_\mathrm{PBH}\gtrsim 2\times 10^{16}\,\mathrm{g}$.

hep-ph↗

arXiv2026

Completing Axion Double Level Crossings

In this work, we present the refinement of axion double level crossings within the context of multi-axion mass mixing, specifically focusing on cases where the number of axions exceeds two. Our investigation reveals that double level crossings are a common phenomenon in the mass mixing of the $Z_{\mathcal N}$ axion and axion-like particles. Physically, these double level crossings involve a first level crossing at high temperatures followed by a second level crossing induced by the $Z_{\mathcal N}$ axion mass transition at $T_{\rm QCD}$. We introduce the general model for double level crossings, along with several toy examples, and redefine the light and heavy axion scenarios. In the light axion scenario, double level crossings can occur multiple times in the large ${\mathcal N}$ limit. However, excessively large values of ${\mathcal N}$ may also prevent the occurrence of double level crossings. Conversely, in the heavy axion scenario, excessively small ${\mathcal N}$ may similarly prevent their occurrence. Our findings also have some intriguing implications for axion cosmology.

hep-ph↗

arXiv2025

Novel Light Dark Matter Detection with Quantum Parity Detector Using Qubit Arrays

We present the design and the sensitivity reach of the Qubit-based Light Dark Matter detection experiment. We propose the novel two-chip design to reduce signal dissipation, with quantum parity measurement to enhance single-phonon detection sensitivity. We demonstrate the performance of the detector with full phonon and quasiparticle simulations. The experiment is projected to detect $\gtrsim 30$ meV energy deposition with nearly $100\%$ efficiency and high energy resolution. The sensitivity to $m_χ\gtrsim 0.01$ MeV dark matter scattering cross section is expected to be advanced by orders of magnitude for both light and heavy mediators, and similar improvements will be achieved for axion and dark photon absorption in the $0.04$-$0.2$ eV mass range.

hep-ph↗

arXiv2025

Identifying Monochromatic Signals in LISA and Taiji via Spectral Split: Gravitational Waves versus Ultralight Dark Matter

The detection of gravitational waves (GWs) has opened a new window to explore the dark Universe. Ultralight dark matter (ULDM), an attractive candidate for dark matter, might induce monochromatic signals in gravitational-wave (GW) laser interferometers. However it is not clear how such signals are disentangled from the GWs emitted by galactic compact binaries. Here we initiate the investigation on the spectral split of monochromatic signals caused by detector's heliocentric motion in space and show the annual modulation can induce distinct structures in the spectral harmonics for GWs and ULDM, which would enable to clearly identify the nature of the signal. We show the physical parameters can be inferred with high precision using the Fisher matrix formalism. Our results provide a practical algorithm for probing ULDM and broaden the scientific objectives of future GW detectors in space, such as LISA and Taiji.

hep-ph↗

arXiv2025

Mass Mixing between QCD Axions

We introduce a novel level crossing phenomenon in the mass mixing between the QCD axions, one canonical QCD axion and one $Z_{\mathcal N}$ axion. The level crossing can take place at or slightly before the QCD phase transition critical temperature, depending on the ratio of the axion decay constants $\sim1.69$. The cosmological evolution of the mass eigenvalues in these two scenarios is similar; however, the transition of axion energy density differs significantly. Finally, we estimate the relic density of the QCD axion dark matter in this context. Additionally, this level crossing may have some interesting cosmological implications.

hep-ph↗

arXiv2025

Axion Mixing in the String Axiverse

String axiverse provides a fascinating and complex landscape for axion physics. The requirement in type IIB string axiverse models necessitates at least two axions to ensure the presence of both a QCD axion candidate and an additional axion-like particle (ALP). In this work, we study axion mass mixing and adopt a bottom-up perspective to investigate what conditions an axion model must satisfy in order to exhibit maximal mixing -- the scenario where the degree of effective mixing is maximized. We find that maximal mixing occurs when the masses of all ALPs are smaller than the zero-temperature mass of the QCD axion, with no two ALP masses being equal, and when the decay constants of all ALPs are uniformly either smaller or larger than the decay constant of the QCD axion. Additionally, the transfer of axion energy density ultimately takes place only between the two axions with the closest masses. These findings provide critical insights into axion dynamics not only within type IIB string axiverse models but also in broader multi-axion mixing frameworks. The potential cosmological implications of axion mass mixing are also addressed at the end.

hep-th↗

arXiv2025

Constraints on evaporating primordial black holes from the AMS-02 positron data

Cosmic-ray (CR) positrons are relatively rare due to their secondary origin and thus sensitive to exotic contributions. Primordial black holes (PBHs) with masses above $\sim 5\times10^{14}\,\mathrm{g}$ can be stable sources of CR positrons due to Hawking radiation. The energies of the evaporated positrons can increase significantly through scattering with the Galactic random magnetic fields during the propagation in the Galaxy, which is a generic feature in diffusive re-acceleration CR propagation models. We show that in well-constrained diffusive re-acceleration models, a significant portion of CR positron flux can enter the energy region of $\mathcal{O}(\text{GeV})$, and can be constrained by the current AMS-02 data. As an example, we show that in the Galprop+Helmod model for CR propagation in the Galaxy and heliosphere, an upper limit of $f_{\text{PBH}}\lesssim2.15\times 10^{-4}$ at PBH mass $2\times 10^{16}$~g can be obtained, which improve the previous constraints from the Voyager CR all-electron data by around an order of magnitude.

hep-ph↗

arXiv2025

Axion effects on gamma-ray spectral irregularities. II: Implications of EBL absorption

The extragalactic background light (EBL) plays a crucial role in the propagation of high-energy particles throughout the Universe. In this work, we explore the impact of the EBL absorption effect on photon to axionlike particle (ALP) conversions from the very-high-energy gamma-ray spectral irregularities. For our purpose, we select four BL Lac blazars: Markarian 501, 1ES 0229+200, PKS 0301-243, and PKS 0447-439 for analysis. Their redshifts range from approximately 0.03 to 0.34. We first discuss the EBL absorption effect on the gamma-ray spectral energy distributions (SEDs) using three common EBL spectral models: Finke-10, Franceschini-17, and Saldana-Lopez-21. Then we consider the photon-ALP conversions in astrophysical magnetic fields. The best-fit chi-square distributions of these EBL models under the ALP assumption in the ALP parameter $\{m_a, g_{aγ}\}$ plane are provided, showing similar distributions. For comparison, we define a new delta chi-square, $χ_d^2$, to quantify the difference in chi-square values. The distributions of $χ_d^2$ and the gamma-ray SEDs corresponding to the maximum delta chi-square, $χ^2_{d, \rm max}$, are also presented for comparison. Our results indicate that the influence of these different EBL models is non-dominant at the low-redshift gamma-ray axionscope. In these cases, choosing the latest model, Saldana-Lopez-21, is sufficient. However, as the redshift of the sources increases, this influence becomes more significant.

hep-ph↗

arXiv2025

Gravitational waves and primordial black holes from axion domain walls in level crossing

In this paper, we investigate the nano-Hertz gravitational waves (GWs) emission and the massive primordial black holes (PBHs) formation from the light QCD axion scenario. We consider the axion domain walls formation from the level crossing induced by the mass mixing between the light $Z_{\mathcal N}$ QCD axion and axion-like particle. A general mixing case is considered that the heavy and light mass eigenvalues do not necessarily have to coincide with the axion masses. In order to form the domain walls, the axions should start to oscillate slightly before the level crossing. The domain walls must annihilate before dominating the Universe to avoid the cosmological catastrophe. Then we focus our attention on the GWs emission from the domain walls annihilation and the PBHs formation from the domain walls collapse. We show the predicted GWs spectra with the peak frequency $\sim 0.2\, \rm nHz$ and the peak amplitude $\sim 5\times 10^{-9}$, which can be tested by the future pulsar timing array projects. In addition, during the domain walls annihilation, the closed walls could shrink to the Schwarzschild radius and collapse into the PBHs. We find that the PBHs in the mass range of $\mathcal{O}(10^5-10^8) M_\odot$ could potentially form in this scenario and account for a small fraction $\sim 10^{-5}$ of the cold dark matter.

hep-ph↗

arXiv2024

Upper limit on the axion-photon coupling from Markarian 421

Markarian 421 is a well-known nearby BL Lac blazar at the redshift $z=0.031$. Many previous works were investigated to constrain the axion-photon coupling from its TeV gamma-ray observations, showing the upper limit on the coupling constant $g_{aγ} \lesssim 2.0\times 10^{-11} \rm \, GeV^{-1}$ for the axion mass $[5.0\times10^{-10} \, {\rm eV} \lesssim m_a \lesssim 5.0\times10^{-7} \, {\rm eV}]$. While in this work, we obtain a more stringent upper limit on the axion-photon coupling from the 1038 days gamma-ray observations of the blazar Markarian 421. The long-term gamma-ray spectra are measured by the collaborations Large Area Telescope on board NASA's Fermi Gamma-ray Space Telescope (Fermi-LAT) and High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory from 2015 June to 2018 July. We show the best-fit spectral energy distributions (SEDs) of Markarian 421 under the null and axion hypotheses. Then we set the axion-photon limit in the $\{m_a, \, g_{aγ}\}$ plane. The 99% $\rm C.L.$ upper limit set by Markarian 421 is $g_{aγ} \lesssim 4.0\times 10^{-12} \rm \, GeV^{-1}$ for the axion mass $[1.0\times10^{-9} \, {\rm eV} \lesssim m_a \lesssim 1.0\times10^{-8} \, {\rm eV}]$. It is the most stringent upper limit in this axion mass region.

hep-ph↗

arXiv2024

Supermassive black holes triggered by QCD axion bubbles

The supermassive black holes (SMBHs) are ubiquitous in the center of galaxies, although the origin of their massive seeds is still unknown. In this paper, we investigate the SMBHs formation from the QCD axion bubbles. In this case, the primordial black holes (PBHs) are considered as the seeds of SMBHs, which are generated from the QCD axion bubbles due to an explicit Peccei-Quinn (PQ) symmetry breaking after inflation. The QCD axion bubbles are formed when the QCD axion starts to oscillate during the QCD phase transition. We consider a general case in which the axion bubbles are formed with the bubble effective angle $θ_{\rm eff}\in(0, \, π]$, leading to the minimum PBH mass $\sim\mathcal{O}(10^4-10^7)M_\odot$ for the axion decay constant $f_a\sim\mathcal{O}(10^{16})\, \rm GeV$. The PBHs at this mass region may account for the seeds of SMBHs.

hep-ph↗

arXiv2024

Linear dynamics and classical tests of the gravitational quantum field theory

We explore the new physics phenomena of gravidynamics governed by the inhomogeneous spin gauge symmetry based on the gravitational quantum field theory. Such a gravidynamics enables us to derive the generalized Einstein equation and an equation beyond it. To simplify the analyses, we linearize the dynamic equations of gravitational interaction by keeping terms up to the leading order in the dual gravigauge field. We then apply the linearized dynamic equations into two particular gravitational phenomena. First, we consider the linearized equations in the absence of source fields, which is shown to have five physical propagating polarizations as gravitational waves, i.e., two tensor modes, two vector modes, and one scalar, instead of two tensor polarizations in the general relativity. Second, we examine the Newtonian limit in which the gravitational fields and the matter source distribution are weak and static. By deriving the associated Poisson equation, we obtain the exact relation of the fundamental interaction coupling in the gravidynamics with the experimentally measured Newtonian constant. We also make use of nonrelativistic objects and relativistic photons to probe the Newtonian field configurations. In particular, the experiments from the gravitational deflection of light rays and the Shapiro time delay can place stringent constraints on the linearized gravidynamics in the gravitational quantum field theory.

gr-qc↗

arXiv2024

Axion limits from the 10-year gamma-ray emission 1ES 1215+303

We present the limits on photon to axionlike particle (ALP) coupling from the 10-year period observations of the TeV BL Lacertae blazar 1ES 1215+303 (with redshift $z=0.130$). The contemporaneous gamma-ray spectra are measured by the collaborations Fermi-LAT and VERITAS with five flux phases from 2008 to 2017, including four low states and one flare. Using these flux phases, we show the spectral energy distributions (SEDs) under the null/ALP hypotheses and set the combined limit on ALP. The 95% $\rm C.L.$ combined limit set by 1ES 1215+303 with the 10-year gamma-ray data is roughly at the photon-ALP coupling constant $g_{aγ} \gtrsim 1.5\times 10^{-11} \rm \, GeV^{-1}$ for the ALP mass $5.0\times10^{-10} \, {\rm eV} \lesssim m_a \lesssim 1.0\times10^{-7} \, {\rm eV}$.

astro-ph.HE↗

arXiv2024

Light QCD Axion Dark Matter from Double Level Crossings

The even light QCD axion called the $Z_{\mathcal N}$ axion can both solve the strong CP problem and account for the dark matter (DM). We point out that the single and double level crossings can naturally take place in the mass mixing between the $Z_{\mathcal N}$ axion and axionlike particle (ALP). The first level crossing occurs much earlier than the QCD phase transition, while the second level crossing occurs exactly during the QCD phase transition if it exists. We also find that the single level crossing can transform into the double level crossings, depending on the ALP mass $m_A$ versus the zero-temperature $Z_{\mathcal N}$ axion mass $m_{a,0}$. Compared with the no level crossing case, the $Z_{\mathcal N}$ axion relic density can be suppressed in the single level crossing, and enhanced or suppressed in the double level crossings.

hep-ph↗

arXiv2023

Diurnal modulation of electron recoils from DM-nucleon scattering through the Migdal effect

Halo dark matter (DM) particles could lose energy due to the scattering off nuclei within the Earth before reaching the underground detectors of DM direct detection experiments. This Earth shielding effect can result in diurnal modulation of the DM-induced recoil event rates observed underground due to the self-rotation of the Earth. For electron recoil signals from DM-electron scatterings, the current experimental constraints are very stringent such that the diurnal modulation cannot be observed for halo DM. We propose a novel type of diurnal modulation effect: diurnal modulation in electron recoil signals induced by DM-nucleon scattering via the Migdal effect. We set so far the most stringent constraints on DM-nucleon scattering cross section via the Migdal effect for sub-GeV DM using the S2-only data of PandaX-II and PandaX-4T with improved simulations of the Earth shielding effect. Based on the updated constraints, we show that the Migdal effect induced diurnal modulation of electron events can still be significant in the low energy region, and can be probed by experiments such as PandaX-4T in the near future.

hep-ph↗

arXiv2023

Azimuthal asymmetry in cosmic-ray boosted dark matter flux

Light halo dark matter (DM) particles up-scattered by high-energy cosmic rays (referred to as CRDM) can be energetic and become detectable at conventional DM and neutrino experiments. We show that the CRDM flux has a novel and detectable morphological feature. Unlike most of the recently proposed boosted DM (BDM) models which predict azimuthally symmetric DM fluxes around the Galactic Center, the CRDM flux breaks the azimuthal symmetry significantly. Using cosmic-ray electron distribution in the whole Galaxy and optimized search region in the sky according to the morphology of the CRDM flux, we derive so far the most stringent constraints on the DM-electron scattering cross section from the Super-Kamiokande (SK) IV data, which improves the previous constraints from the SK-IV full-sky data by more than an order of magnitude. Based on the improved constraints, we predict that the azimuthal symmetry-breaking effect can be observed in the future Hyper-Kamiokande experiment at $\sim 3σ$ level.

hep-ph↗

arXiv2022

Enhanced cosmic-ray antihelium production from dark matter annihilation through light mediators

Cosmic-ray (CR) antihelium is an important probe for the indirect search of dark matter (DM) annihilation in the Galaxy. However, due to stringent constraints from the measurements of CR antiprotons and $γ$-rays, the flux of CR antihelium from the conventional DM direct annihilation into Standard Model final states is expected to be far below the sensitivity of the current experiments. We show that the production of antihelium can be significantly enhanced if the DM particles annihilate through light mediator particles with a mass $m_ϕ\approx 8$ GeV close to the antihelium production threshold. After taking into account the constraints from the AMS-02 antiproton data and the Fermi-LAT $γ$-ray data on the spheroidal dwarf galaxies, we find that in this scenario the CR antihelium flux can be enhanced by three orders of magnitude, which makes it within the sensitivity of the ongoing AMS-02 experiment.

hep-ph↗