arXiv subjects

Chui-Fan Kong

Publications and source records attributed to Chui-Fan Kong.

10 recordsLinked to original sources

arXiv2026

RG Running of Multiple Neutrino Mixing Parameters at Oscillation Experiments

If the new physics scale is within the energy scale of neutrino oscillation experiments, it may lead to a renormalization group (RG) running effect between the production and detection processes as well as between different experiments. It is then possible to use multiple neutrino oscillation experiments to disentangle the multiple RG running parameters. We investigate this effect in a general model-independent sense for a variety of flavor structures in the context of upcoming experiments DUNE-ND, JUNO-TAO, and FASER$\nu$2 that span a large range in neutrino energies and many different flavor combinations. We find strong sensitivity to the running effects of new physics with combination of these experiments, especially the possibility of addressing the non-trivial degeneracies.

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arXiv2026

Circumstellar Medium of Supernovae as New Probes for Feebly-interacting Particles

We propose a novel strategy to probe feebly-interacting particles (FIPs) by exploiting the dense, confined circumstellar medium (CSM) surrounding core-collapse supernovae (CCSNe). FIPs produced in the proto-neutron star can deposit substantial visible energy into the CSM via decay prior to the shock breakout from the progenitor star. This energy injection heats and ionizes the CSM, establishing a FIP-induced photosphere that generates distinctive precursor blackbody emission. Using early-time observations of SN 2023ixf, we translate the non-detection of excessive precursor luminosity into stringent new constraints on MeV-scale dark photons as an exemplary model. Our results significantly extend existing CCSN bounds and exclude previously unexplored regions of parameter space. We further demonstrate that the FIP-induced dust sublimation offers robust diagnostics for future Galactic SNe, opening a new avenue to explore the dark sector.

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arXiv2025

Neutrinoless Double Beta Decay in Light of JUNO First Data

The first results from the JUNO reactor neutrino oscillation experiment improve our knowledge of neutrino masses and mixing parameters, especially the solar angle $\theta_s \equiv \theta_{12}$ and the solar mass squared difference $\Delta m^2_s \equiv \Delta m^2_{21}$. We discuss the implications of these results on neutrinoless double beta decay by itself and in combination with the global fit of neutrino oscillation experiments, the JUNO first data, and cosmological constraints on the neutrino mass sum. For the effective mass $\langle m_{ee} \rangle$, the uncertainties in its lower limits for both mass orderings and upper limits for the normal ordering are largely reduced. Since the cosmological CMB and DESI BAO data put a stringent constraint on the neutrino mass scale, we also show how the probability distribution of both the real and imaginary parts of the effective mass $\langle m_{ee} \rangle$ on the complex plane is affected. Especially, the funnel region with $|\langle m_{ee} \rangle| \lesssim 1$\,meV receives larger chance to happen. Correspondingly, the chance of determining the two Majorana CP phases simultaneously in this region also increases with reduced uncertainty.

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arXiv2025

CP Prediction from Residual $\mathbb Z_2^s$ and $\overline{\mathbb Z}_2^s$ Symmetries with JUNO First Data

The JUNO first data and the recent neutrino global fit results are implemented in the sum rule from the residual $\mathbb Z^s_2$ and $\overline{\mathbb Z}^s_2$ symmetries to make prediction of the leptonic Dirac CP phase $\delta_D$. Without involving model parameters, the probability distribution of $\delta_D$ can be readily obtained from the experimental measurements of the three mixing angles. We then confront the theoretical predictions with the global fit results for the CP phase as well as the T2K and NOvA joint analysis for their CP measurement to give the data preference of the two residual symmetries with Bayes factor for both normal and inverted orderings. We further extend our analysis to a two-dimensional probability distribution to fully explore the correlation between the CP phase $\delta_D$ and the atmospheric angle $\theta_a \equiv \theta_{23}$.

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arXiv2025

High-Precision Physics Experiments at Huizhou Large-Scale Scientific Facilities

In response to the capabilities presented by the High-Intensity Heavy Ion Accelerator Facility (HIAF) and the Accelerator-Driven Subcritical System (CiADS), as well as the proposed Chinese Advanced Nuclear Physics Research Facility (CNUF), we are assembling a consortium of experts in relevant discipline--both domestically and internationally--to delineate high-precision physics experiments that leverage the state-of-the-art research environment afforded by CNUF. Our focus encompasses six primary domains of inquiry: hadron physics--including endeavors such as the super eta factory and investigations into light hadron structures; muon physics; neutrino physics; neutron physics; the testing of fundamental symmetries; and the exploration of quantum effects within nuclear physics, along with the utilization of vortex accelerators. We aim to foster a well-rounded portfolio of large, medium, and small-scale projects, thus unlocking new scientific avenues and optimizing the potential of the Huizhou large scientific facility. The aspiration for international leadership in scientific research will be a guiding principle in our strategic planning. This initiative will serve as a foundational reference for the Institute of Modern Physics in its strategic planning and goal-setting, ensuring alignment with its developmental objectives while striving to secure a competitive edge in technological advancement. Our ambition is to engage in substantive research within these realms of high-precision physics, to pursue groundbreaking discoveries, and to stimulate progress in China's nuclear physics landscape, positioning Huizhou as a preeminent global hub for advanced nuclear physics research.

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arXiv2025

Testing New Physics in Oscillations at a Neutrino Factory

A neutrino factory is a potential successor to the upcoming generation of neutrino oscillation experiments and a possible precursor to next-generation muon colliders. Such a machine would provide a well-characterized beam of $\nu_\mu$, $\bar\nu_\mu$, $\nu_e$, and $\bar\nu_e$ neutrinos with comparable statistics. Here we show the sensitivity of a neutrino factory to new oscillation physics scenarios such as vector neutrino non-standard interactions and CPT violation. We study two different potential setups for a neutrino factory with different assumptions on charge identification in the far detector. We find that 10 years of a neutrino factory combined with 10 years of DUNE can improve over most of the current constraints on these scenarios and even over forecasted constraints by 20 years of DUNE. Additionally, we find that a neutrino factory can break degeneracies between the standard oscillation parameters and neutrino non-standard interaction parameters present at DUNE.

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arXiv2024

Testing the RG Running of the Leptonic Dirac CP Phase with Reactor Neutrinos

We propose the possibility of using the near detector at reactor neutrino experiments to probe the renormalization group (RG) running effect on the leptonic Dirac CP phase $\delta_D$. Although the reactor neutrino oscillation cannot directly measure $\delta_D$, it can probe the deviation $\Delta \delta \equiv \delta_D(Q^2_d) - \delta_D(Q^2_p)$ caused by the RG running. Being a key element, the mismatched momentum transfers at neutrino production ($Q^2_p$) and detection ($Q^2_d$) processes can differ by two orders. We illustrate this concept with the upcoming Taishan Antineutrino Observatory (TAO, also known as JUNO-TAO) experiment and obtain the projected sensitivity to the CP RG running beta function $\beta_\delta$.

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arXiv2024

Testing the Origins of Neutrino Mass with Supernova Neutrino Time Delay

The origin of neutrino masses remains unknown. Both the vacuum mass and the dark mass generated by the neutrino interaction with dark matter (DM) particles or fields can fit the current oscillation data. The dark mass squared is proportional to the DM number density and therefore varies on the galactic scale with much larger values around the Galactic Center. This affects the group velocity and the arrival time delay of core-collapse supernovae (SN) neutrinos. This time delay, especially for the $\nu_e$ neutronization peak with a sharp time structure, can be used to distinguish the vacuum and dark neutrino masses. For illustration, we explore the potential of DUNE which is sensitive to $\nu_e$. Our simulations show that DUNE can distinguish the two neutrino mass origins at more than $5\sigma\,$C.L., depending on the observed local value of neutrino mass, the neutrino mass ordering, the DM density profile, and the SN location.

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arXiv2023

Neutrino CP Measurement in the Presence of RG Running with Mismatched Momentum Transfers

The neutrino mixing parameters are expected to have RG running effect in the presence of new physics. If the momentum transfers at production and detection mismatch with each other, the oscillation probabilities are generally modified and become dependent on not just the neutrino energy but also the momentum transfer. Even in the limit of vanishing baseline, the transition probability for the appearance channel is interestingly not zero. This would significantly affect the sensitivity of the genuine leptonic Dirac CP phase. We further explore the possibility of combing the long- and short-baseline neutrino experiments to constrain such RG running effect for the purpose of guaranteeing the CP measurement. To simulate the double dependence on the neutrino energy and momentum transfer, we extend the usual GLoBES simulation of fixed baseline experiments and use a two-dimensional $\chi^2$ analysis to obtain sensitivities.

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arXiv2022

Improving CP Measurement with THEIA and Muon Decay at Rest

We explore the possibility of using the recently proposed THEIA detector to measure the $\bar ν_μ\rightarrow \bar ν_e$ oscillation with neutrinos from a muon decay at rest ($μ$DAR) source to improve the leptonic CP phase measurement. Due to its intrinsic low-energy beam, this $μ$THEIA configuration ($μ$DAR neutrinos at THEIA) is only sensitive to the genuine leptonic CP phase $δ_D$ and not contaminated by the matter effect. With detailed study of neutrino energy reconstruction and backgrounds at the THEIA detector, we find that the combination with the high-energy DUNE can significantly reduce the CP uncertainty, especially around the maximal CP violation cases $δ_D = \pm 90^\circ$. Both the $μ$THEIA-25 with 17kt and $μ$THEIA-100 with 70kt fiducial volumes are considered. For DUNE + $μ$THEIA-100, the CP uncertainty can be better than $8^\circ$.

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