arXiv subjects

Shun Zhou

Publications and source records attributed to Shun Zhou.

At least 19 recordsLinked to original sources

arXiv2026

Deciphering Matter Invariants via Renormalization Group Equations for Neutrino Oscillations

We utilize renormalization group equations (RGEs) for neutrino oscillations in matter to decipher the structure of exact matter invariants. By combining the RGEs with the $S^{}_3$ permutation covariance under relabeling of the neutrino mass eigenstates, we recast all five algebraically independent matter invariants in the three-flavor framework as exact first integrals. Treating the matter potential as a matter spurion and imposing the cancellation conditions for the $1/\widetilde\Delta_{ij}^{}$ poles in the RGEs, we further prove that the three-flavor framework contains only two independent monomial invariants, which can be related to the Naumov and Toshev relations. We then extend the analysis to the four-flavor framework, where we uncover a complete set of eleven algebraically independent matter invariants and prove that the rank-two electron--sterile spurion obstructs the common pole cancellation required for any nontrivial multiplicative monomial invariant.

hep-ph↗

arXiv2026

Revealing precision bounds on neutrino oscillation parameters with quantum estimation theory

Quantum estimation theory provides ultimate precision bounds on parameter estimation, independent of experimental setups. In this article, we apply this theoretical framework to neutrino oscillations, aiming to clarify some subtle issues and reveal the maximum achievable precision of oscillation parameters. First, taking the example of two-flavor oscillations, we clarify how the quantum Fisher information (QFI) depends on the choice of bases when the basis transformation itself involves the parameters in question. Then, for three-flavor oscillations, we compute the QFI matrix for electron and muon neutrino states in the flavor basis and derive analytical expressions and numerical results for both diagonal and off-diagonal elements. The implications of off-diagonal correlations for multiparameter estimation are discussed, and the quantum Cram\'{e}r-Rao bounds on the precision of oscillation parameters for typical reactor and long-baseline accelerator neutrino experiments are obtained. Our results establish a theoretical benchmark for the ultimate precision achievable in future neutrino oscillation experiments.

hep-ph↗

arXiv2025

Precision Higgs Boson Probe of Type-II Seesaw Models

Despite direct searches at the LHC excluding tripletlike Higgs bosons up to several hundred GeV over much of the type-II seesaw model parameter space, parts of it -- most notably those featuring ``cascade decays'' of the charged Higgs bosons into their neutral partners and off-shell $W$ bosons -- still remain unconstrained. Meanwhile, measurements of the diphoton signal strength of the Standard Model (SM) Higgs boson -- potentially modified by loop contributions from tripletlike Higgs states -- are in good agreement with the SM expectation, with combined experimental uncertainties currently at approximately 8%. Given the trend in previous measurements, it is expected that future precision Higgs measurements at the HL-LHC and a future lepton collider such as the Circular Electron Positron Collider, Future Circular Collider, or Muon Collider will be consistent the standard diphoton signal strength, albeit with significantly reduced uncertainties, down to about 0.7%. Presuming this and considering all relevant constraints, we explore whether such increasingly precise diphoton measurements can indirectly probe the parameter space that currently evades direct searches. We find that subpercent-level determinations of the diphoton rate will decisively probe a substantial fraction of this otherwise elusive region.

hep-ph↗

arXiv2025

Probing unitarity violation of lepton flavor mixing matrix with reactor antineutrinos at JUNO and TAO

Motivated by the precise measurements of neutrino oscillation parameters at Jiangmen Underground Neutrino Observatory (JUNO), we investigate the possibility of probing the unitarity violation of lepton flavor mixing matrix solely with reactor antineutrinos. First, we stress that it is necessary to reconsider the production and detection of neutrinos in a self-consistent way, apart from neutrino propagation, when analyzing experimental sensitivities to unitarity violation. Then, concentrating on JUNO and its satellite experiment Taishan Antineutrino Observatory (TAO), we demonstrate how the event rates of inverse beta decays (i.e., $\overline{\nu}^{}_e + p \to e^+ + n$) for observing $\overline{\nu}^{}_e \to \overline{\nu}^{}_e$ oscillations, and those of elastic antineutrino-electron scattering (i.e., $\overline{\nu}^{}_\alpha + e^- \to \overline{\nu}^{}_\alpha + e^-$ with $\alpha = e, \mu, \tau$) for $\overline{\nu}^{}_e \to \overline{\nu}^{}_\mu$ and $\overline{\nu}^{}_e \to \overline{\nu}^{}_\tau$ oscillations, depend on the parameters characterizing unitarity violation. Our investigation will be useful for JUNO and TAO to place independent constraints with more data in the near future.

hep-ph↗

arXiv2025

The detection of cosmic neutrino background with helicity-changing decays

In this talk, we present the investigation of the invisible decays of a heavy massive neutrino into a lighter neutrino and a massless Nambu-Goldstone boson, i.e., $\nu_i^{} \to \nu_j^{} + \phi$. The total decay rates are calculated in the most general case, where the individual helicities of both parent and daughter neutrinos are specified. We then examine the evolution of the number densities of cosmological relic neutrinos throughout the expansion of the Universe, and explore the consequent impacts on the capture rates in PTOLEMY-like experiments. The total event rates can be significantly modified compared to those in the scenario of stable neutrinos, with helicity-changing decays playing an especially important role in the Dirac neutrino case.

hep-ph↗

arXiv2025

One-Loop Effects in the Neutrino Matter Potential and Implications for Non-Standard Interactions

In this work, we emphasize that it is necessary to take into account one-loop corrections of $2.0\%$ to the neutrino matter potential in the precision measurements of neutrino oscillation parameters and in the experimental searches for new physics beyond the Standard Model. With the numerical simulation of the DUNE experiment, we study how radiative corrections to the matter potential affect neutrino oscillation probabilities, and thus, the event rates in the presence of neutrino non-standard interactions (NSIs). We find that neglecting one-loop corrections may lead to wrong conclusions for the discovery of NSIs. The implications for the determination of neutrino mass ordering and constraints on the NSI parameters in future long-baseline accelerator neutrino experiments are explored in a quantitative way.

hep-ph↗

arXiv2025

One-loop Renormalization of the Type-I Seesaw Model in the On-shell Scheme

In this paper, we continue to carry out the one-loop renormalization of the type-I seesaw model in the on-shell scheme. Different from the modified minimal-subtraction ($\overline{\rm MS}$) scheme, such an investigation is mainly motivated by the fact that the on-shell scheme has been widely adopted in the renormalization of the standard electroweak theory and implemented for its precision tests. We first specify the physical parameters in the on-shell scheme, and then fix the corresponding counterterms through on-shell renormalization conditions. In the presence of massive Majorana neutrinos, we propose a practical method to determine gauge-independent counterterms for the lepton flavor mixing matrix. With the explicit counterterms in both the $\overline{\rm MS}$ and on-shell schemes, we establish the matching relations of the electric charge, physical masses and flavor mixing matrix elements between these two schemes. Our results in the present and previous papers lay the foundation for precision calculations in the type-I seesaw model.

hep-ph↗

arXiv2025

Towards a detection of reactor $\overline{\nu}^{}_e \to \overline{\nu}^{}_\mu$ and $\overline{\nu}^{}_e \to \overline{\nu}^{}_\tau$ oscillations with possible CP violation

We propose an unprecedented detection of reactor $\overline{\nu}^{}_e \to \overline{\nu}^{}_\mu$ and $\overline{\nu}^{}_e \to \overline{\nu}^{}_\tau$ oscillations by using elastic antineutrino-electron scattering processes $\overline{\nu}^{}_\alpha + e^- \to \overline{\nu}^{}_\alpha + e^-$ (for $\alpha = e, \mu, \tau$), among which the $\overline{\nu}^{}_e$ events can be singled out by accurately measuring the $\overline{\nu}^{}_e$ flux via the inverse beta decay $\overline{\nu}^{}_e + p \to e^+ + n$. A proof-of-concept study shows that such measurements will not only be able to test the conservation of probability for reactor antineutrino oscillations, but also offer a new possibility to probe leptonic CP violation at the one-loop level.

hep-ph↗

arXiv2025

A Mutual-Structure Weighted Sub-Pixel Multimodal Optical Remote Sensing Image Matching Method

Sub-pixel matching of multimodal optical images is a critical step in combined application of multiple sensors. However structural noise and inconsistencies arising from variations in multimodal image responses usually limit the accuracy of matching. Phase congruency mutual-structure weighted least absolute deviation (PCWLAD) is developed as a coarse-to-fine framework. In the coarse matching stage, we preserve the complete structure and use an enhanced cross-modal similarity criterion to mitigate structural information loss by PC noise filtering. In the fine matching stage, a mutual-structure filtering and weighted least absolute deviation-based is introduced to enhance inter-modal structural consistency and accurately estimate sub-pixel displacements adaptively. Experiments on three multimodal datasets-Landsat visible-infrared, short-range visible-near-infrared, and UAV optical image pairs demonstrate that PCWLAD consistently outperforms eight state-of-the-art methods, achieving an average matching accuracy of approximately 0.4 pixels. The software and datasets are publicly available at https://github.com/huangtaocsu/PCWLAD.

cs.CV↗

arXiv2025

One-loop Renormalization of the Type-I Seesaw Model in the Modified Minimal-subtraction Scheme

Extending the Standard Model (SM) with three right-handed neutrinos, the type-I seesaw model serves as the simplest and most natural scenario to successfully explain both tiny neutrino masses and the baryon number asymmetry in the Universe. In this paper, we perform a complete one-loop renormalization of the type-I seesaw model in the modified minimal-subtraction ($\overline{\rm MS}$) scheme. The one-loop self-energy corrections of charged leptons and Majorana neutrinos are calculated in the $R_\xi^{}$ gauge, and the explicit expressions of all the counterterms for wave functions, fermion masses and the leptonic flavor mixing matrix are given. Furthermore, adopting the Euler-like parametrization of the $6\times 6$ unitary leptonic flavor mixing matrix, we derive one-loop renormalization-group equations for all the physical parameters in the $\overline{\rm MS}$ scheme, including neutrino masses, mixing angles and CP-violating phases. The modification of the one-loop renormalization of the original SM parameters due to the presence of heavy Majorana neutrinos is investigated as well. In this way, we provide a self-consistent theoretical framework to thoroughly test the type-I seesaw model at the one-loop level with future precision data.

hep-ph↗

arXiv2025

Probing Cosmic Neutrino Background through Parametric Fluorescence

We point out that relic neutrinos from the Big Bang may induce the parametric fluorescence in atomic or molecular systems, which offers a novel way to discover cosmic neutrino background. By coherently scattering with molecular energy levels, a massive neutrino can spontaneously ``decay" into a lighter neutrino and an infrared signal photon, i.e., $\nu^{}_{i} + M \to \nu^{}_{j} + \gamma^{}_{\rm S} + M$, where the molecular state $M$ remains unchanged after the scattering. Because the amplitudes of different radiants are matched in phase, the rate is coherently enhanced and proportional to the squared density of ambient dipoles. When the energy transfer from neutrinos coincides with the energy-level difference, the fluorescence will be on resonance. Near the resonance, the rate is proportional to the square of the coherence time $T^{}_{\rm c}$ of the ensemble. For a nominal target volume of $5~{\rm m^3}$ (or $5~{\rm cm^3}$), the signal rate can reach $1~{\rm yr}^{-1}$ for $T^{}_{\rm c} = 10~{\rm ns}$ (or $T^{}_{\rm c} = 10~{\rm \mu s}$). This event rate appears to be very promising in consideration of an even longer coherence time that is achievable in solid systems.

hep-ph↗

arXiv2025

Fourier ptychographic microscopy aided with transport of intensity equation for robust full phase spectrum reconstruction

Fourier ptychographic microscopy (FPM) is a pivotal computational imaging technique that achieves phase and amplitude reconstruction with high resolution and wide field of view, using low numerical aperture objectives and LED array illumination. Despite its unique strengths, FPM remains fundamentally limited in retrieving low spatial frequency phase information due to the absence of phase encoding in all brightfield illumination angles. To overcome this, we present a novel hybrid approach that combines FPM with the transport of intensity equation (TIE), enabling accurate, full-spectrum phase retrieval without compromising system simplicity. Our method extends standard FPM acquisitions with a single additional on-axis defocused image, from which low-frequency phase components are reconstructed via TIE method, employing large defocus distance to suppress low-frequency artifacts and enhance robustness to intensity noise. To additionally compensate for defocus-induced magnification variations caused by spherical wavefront illumination, we employ an affine transform-based correction scheme upon image registration. Notably, by restoring the missing low-frequency content, our hybrid method appears capable of recovering phase values beyond the conventional 0-2{\pi} range - an area where conventional FPM techniques often struggle when dealing with optically thick samples. We validated our method using a quantitative phase test target for benchmarking accuracy and biological cheek cells, mouse neurons, and mouse brain tissue slice samples to demonstrate applicability for in vitro bioimaging. Experimental results confirm substantial improvements in phase reconstruction fidelity across spatial frequencies, establishing this hybrid FPM+TIE framework as a practical and high-performance solution for quantitative phase imaging in biomedical and optical metrology applications.

physics.optics↗

arXiv2025

Effects of the Matter Potential at One-Loop Level on Neutrino Oscillations in Long-Baseline Experiments

In this work, we investigate in a quantitative way how much radiative corrections to the matter potential for neutrino oscillations can impact the sensitivity to neutrino mass ordering in long-baseline accelerator experiments. Using numerical simulations for the future experiment DUNE, we find that the statistical significance for excluding the incorrect mass ordering can be enhanced by about $0.4\sigma$ if a one-loop correction of $2.0\%$ -- based on the Fermi coupling constant $G^{}_\mu$ derived from measurements of muon lifetime -- is included. The radiative corrections at one-loop level lead to resolving the neutrino mass ordering at $5\sigma$ confidence level 4-9 days earlier than at tree level. In contrast, the sensitivity to leptonic CP violation in DUNE is essentially unchanged. Finally, we emphasize that one-loop corrections should be incorporated into analyses of future neutrino oscillation data in a consistent and systematic manner.

hep-ph↗

arXiv2025

Neutrino Theory in the Precision Era

This document summarises discussions on future directions in theoretical neutrino physics, which are the outcome of a neutrino theory workshop held at CERN in February 2025. The starting point is the realisation that neutrino physics offers unique opportunities to address some of the most fundamental questions in physics. This motivates a vigorous experimental programme which the theory community fully supports. \textbf{A strong effort in theoretical neutrino physics is paramount to optimally take advantage of upcoming neutrino experiments and to explore the synergies with other areas of particle, astroparticle, and nuclear physics, as well as cosmology.} Progress on the theory side has the potential to significantly boost the physics reach of experiments, as well as go well beyond their original scope. Strong collaboration between theory and experiment is essential in the precision era. To foster such collaboration, \textbf{we propose to establish a CERN Neutrino Physics Centre.} Taking inspiration from the highly successful LHC Physics Center at Fermilab, the CERN Neutrino Physics Centre would be the European hub of the neutrino community, covering experimental and theoretical activities.

hep-ph↗

arXiv2025

Wigner-like Parametrization of Canonical Seesaw Models

In this paper, we introduce the Wigner parametrization of unitary matrices and then apply it to the full description of canonical seesaw models, which extend the Standard Model with three right-handed neutrino singlets and account simultaneously for tiny Majorana neutrino masses and the baryon number asymmetry in the Universe. In the Wigner parametrization, the strong hierarchy between the electroweak scale $\Lambda^{}_{\rm EW} \approx 10^2~{\rm GeV}$ and the seesaw scale $\Lambda^{}_{\rm SS} \approx 10^{14}~{\rm GeV}$ is generally captured by three small rotation angles $\{\vartheta^{}_1, \vartheta^{}_2, \vartheta^{}_3\} \approx {\cal O}(\Lambda^{}_{\rm EW}/\Lambda^{}_{\rm SS})$, and all the remaining parameters reside in four $3\times 3$ unitary matrices. The connection between the Wigner parametrization and those in the literature is also established.

hep-ph↗

arXiv2024

Elastic Neutrino-electron Scattering at the One-loop Level in the Standard Model

In this paper, we perform a complete calculation of the differential cross section for elastic neutrino-electron scattering at the one-loop level in the Standard Model (SM), by using up-to-date values of relevant input parameters in the on-shell renormalization scheme. A careful comparison with the calculation done by Sarantakos, Sirlin and Marciano more than forty years ago in the same scheme is carried out, and an excellent agreement is found if the same values of input parameters are taken. Then we apply our results to compute the event rates for the detection of reactor antineutrinos in both JUNO and TAO experiments, which are now under construction and will soon be in operation. It should be emphasized that one-loop radiative corrections in the SM must be taken into account in the first place when searching for possible new-physics effects in the coming era of precision neutrino physics.

hep-ph↗

arXiv2024

Cascade of phase transitions and large magnetic anisotropy in a triangle-kagome-triangle trilayer antiferromagnet

Spins in strongly frustrated systems are of intense interest due to the emergence of intriguing quantum states including superconductivity and quantum spin liquid. Herein we report the discovery of cascade of phase transitions and large magnetic anisotropy in the averievite CsClCu5P2O10 single crystals. Under zero field, CsClCu5P2O10 undergoes a first-order structural transition at around 225 K from high temperature centrosymmetric P-3m1 to low temperature noncentrosymmetric P321, followed by an AFM transition at 13.6 K, another structural transition centering at ~3 K, and another AFM transition at ~2.18 K. Based upon magnetic susceptibility and magnetization data with magnetic fields perpendicular to the ab plane, a phase diagram, consisting of a paramagnetic state, two AFM states and four field-induced states including two magnetization plateaus, has been constructed. Our findings demonstrate that the quasi-2D CsClCu5P2O10 exhibits rich structural and metamagnetic transitions and the averievite family is a fertile platform for exploring novel quantum states.

cond-mat.str-el↗

arXiv2024

Helicity-changing Decays of Cosmological Relic Neutrinos

In this paper, we examine the possibility that massive neutrinos are unstable due to their invisible decays $\nu^{}_i \to \nu^{}_j + \phi$, where $\nu^{}_i$ and $\nu^{}_j$ (for $i, j = 1, 2, 3$) are any two of neutrino mass eigenstates with masses $m^{}_i > m^{}_j$ and $\phi$ is a massless Nambu-Goldstone boson, and explore the implications for the detection of cosmological relic neutrinos in the present Universe. First, we carry out a complete calculation of neutrino decay rates in the general case where the individual helicities of parent and daughter neutrinos are specified. Then, the invisible decays of cosmological relic neutrinos are studied and their impact on the capture rates on the beta-decaying nuclei (e.g., $\nu^{}_e + {^3{\rm H}} \to {^3{\rm He}} + e^-$) is analyzed. The invisible decays of massive neutrinos could substantially change the capture rates in the PTOLEMY-like experiments when compared to the case of stable neutrinos. In particular, we find that the helicity-changing decays of Dirac neutrinos play an important role whereas those of Majorana neutrinos have no practical effects. However, if a substantial fraction of heavier neutrinos decay into the lightest one, the detection of relic neutrinos will require a much higher energy resolution and thus be even more challenging.

hep-ph↗