arXiv subjects

Zhengyun You

Publications and source records attributed to Zhengyun You.

At least 19 recordsLinked to original sources

arXiv2026

Feasibility Study of $e^+e^-\to η_cJ/ψ$ Production and Fully-Charmed Tetraquark Searches at STCF

The proposed high-luminosity Super Tau-Charm Facility (STCF) offers a clean experimental environment for threshold studies of exotic hadrons. In this Letter, we evaluate the expected significance for the fully-charmed vector tetraquark candidate $T_{4c}$ in the $e^+e^- \to η_c J/ψ$ channel at the STCF. Using Monte Carlo simulations of an energy scan from $\sqrt{s}=6.71$ to $6.79~\mathrm{GeV}$ with $100~\mathrm{fb}^{-1}$ per point, we adopt a high-efficiency single-tag (ST) reconstruction of $J/ψ$ leptonic decays as the primary strategy, with a double-tag (DT) reconstruction of $η_c \to K^+K^-π^0$ retained as an independent cross-check. Because the signal cross section is governed by the still-uncertain dielectron width $Γ_{ee}$, we consider three benchmark hypotheses, $Γ_{ee}=0.25, 0.5, 1~\mathrm{eV}$. The corresponding expected ST significances are $5.1\,σ$, $10.6\,σ$, and $20.5\,σ$, respectively. These results indicate that the STCF can provide meaningful sensitivity to fully-charmed tetraquark states near threshold.

hep-ex↗

arXiv2026

The muon Moonshot: Moon subsurface tomography with upward-going muons

We propose a novel muon Moonshot concept for lunar subsurface tomography based on upward-going muons originated from the lunar regolith. Unlike the Earth, the Moon lacks an atmosphere, leaving a dense regolith below and a near-vacuum environment above. Consequently, while most downward-going hadrons are absorbed before decaying, upward-going hadrons escaping the regolith can decay in flight, producing a significant source of lunar muons. These muons are detectable by instruments on the lunar surface or in near-lunar orbit. We perform Monte Carlo simulations to investigate their energy spectra, angular distributions, and integrated fluxes under various theoretical and detector configurations. The results indicate that the lunar muon flux is sensitive to detector altitude under a flat-terrain assumption, demonstrating its potential as a novel non-invasive probe of shallow subsurface voids. We also present case studies on the detection of underground cavities and water resources, with cavity-induced flux variations observable in less than two minutes and weaker water signals distinguishable after about 36 minutes of data collection with a $1~\mathrm{m^2}$ detector, and discuss potential implementations in future lunar missions.

astro-ph.EP↗

arXiv2026

Mini-review of charmonium weak decays at BESIII

The weak decays of charmonium states such as $J/ψ$ and $ψ(2S)$ are instrumental in probing both nonperturbative QCD dynamics and the flavor structure of the Standard Model (SM). The extreme rarity of charmonium weak decays renders them highly sensitive to physics beyond the SM, particularly in channels that are heavily suppressed in the SM, such as flavor-changing neutral-current (FCNC) decays. This review highlights the critical role of the BESIII experiment, which leverages an unprecedented data sample of over $10^{10}$ $J/ψ$ and $2.7\times10^{9}$ $ψ(2S)$ events to achieve leading sensitivity in searches for charmonium weak decays. We present the latest and most stringent upper limits established by BESIII on various semileptonic, nonleptonic, and FCNC charmonium weak decay channels.

hep-ex↗

arXiv2026

Dark photon search status in $τ-c$ energy region

The dark photon plays an important role as a portal to dark matter and has been extensively studied on both experimental and theoretical frontiers. However, as no signals have been observed, the whereabouts of the dark photon remain a long-standing open question. With the proposal of a future $τ-c$ facility, this proceeding reviews and summarizes the current experimental status of the dark photon in the $τ-c$ energy region, which is expected to provide a reference for future searches. The experimental status indicates that the dark photon in the $τ-c$ energy region remains highly promising, highlighting the requirement for larger data samples or new methods to further investigate the benchmarks related to the observed cosmic dark matter.

hep-ph↗

arXiv2026

A method for converting high energy physics detector description into a Unity visualization

Detector visualization plays a vital role in high energy physics (HEP) experiments, yet existing detector descriptions, such as GDML, lack compatibility with industrial 3D tools. We present an automated conversion framework that transforms four major HEP detector descriptions, including GDML, Geant4, ROOT and DD4hep, into standardized FBX models compatible with a industrial 3D platform called Unity. This solution enables HEP detectors to be directly visualized in the professional 3D ecosystem, which is of great help for detector design verification, event display development, and public participation.

hep-ex↗

arXiv2026

Search for charm rare decays at BESIII

The BESIII experiment has collected 2.6 billion $ψ(3686)$ events, 10 billion events, 20 $fb^{-1}$ of $D$ meson pairs at 3.773 GeV, and 7.33 $fb^{-1}$ of $D_sD_s^*$ events from 4.128 to 4.226 GeV. These huge data samples allow us to search for rare or forbidden processes in charm hadron decays. We summarize the recent research of charm rare decays at BESIII in this paper.

hep-ex↗

arXiv2025

Search for dark sector at BESIII

BESIII experiment has collected a large data sample of charmonium, charm mesons, hyperons, and other light mesons. These data provide a unique opportunity to explore the dark sector beyond the Standard Model, particularly for dark sectors that couple to charm quarks or other light quarks, and for dark sectors with masses in the $τ-c$ energy region. We present recent dark sector search results from the BESIII experiment, including the search for massless dark photons in $D^0\toωγ'$ and $D^0\toγγ'$, the search for invisible decays of $K^0_S$, the search for dark baryon particles in $Ξ^-\toπ^-χ$, the search for massless particles in $Σ^+\to p + \rm{invisible}$, and the search for axion-like particles in $J/ψ\toγa$ with $a\toγγ$.

hep-ex↗

arXiv2025

Observation of the decay $η_c\toγγ$ at BESIII

In the decays of $η_c\toγγ$ and $J/ψ\toγη_c$, there are discrepancies between the theoretical calculations and the PDG experimental values, referred to as the charmonium QCD puzzle. We observe the decay $η_c\toγγ$ in $J/ψ\toγη_c$ using $(2712.4\pm14.3)\times10^{6}$ $ψ(3686)$ events collected with the BESIII detector, and determine the product branching fraction $\mathcal{B}(J/ψ\toγη_c)\times\mathcal{B}(η_c\toγγ)=(5.23\pm0.26_{\rm{stat.}}\pm0.30_{\rm{syst.}})\times10^{-6}$. This measurement is consistent with the two most recent lattice QCD calculations, providing significant input toward resolving the charmonium QCD puzzle.

hep-ex↗

arXiv2025

Experimental dataset from BESIII detector at Beijing electron positron collider

In the BESIII detector at Beijing electron positron collider, billions of events from $e^+e^-$ collisions were recorded. These events passing through the trigger system were saved in raw data format files. They play an important role in the study of physics in tau-charm energy region. Here, we published an $e^+e^-$ collision dataset containing both Monte Carlo simulation samples and real data collected by the BESIII detector. The data pass through the detector trigger system, file format conversion, and physics information extraction and finally save the physics information and detector response in text format files. This dataset is publicly available and is intended to provide interested scientists and those outside of the BESIII collaboration with event information from BESIII, which can be used to understand physics research in $e^+e^-$-collisions, developing visualization projects for physics education, public outreach, and science advocacy.

hep-ex↗

arXiv2025

Dark sector search at BESIII

The Standard Model has achieved significant success in particle physics; however, there are still some unresolved puzzles beyond it. This motivates the exploration of the dark sector. We present the recent dark sector search results from BESIII experiment, which include the search for axion-like particles in the $J/ψ$ data set, the search for muon-philic particles in muon radiation, the search for massless dark photons in $D^0\toωγ'$ and $D^0\toγγ'$, and the search for invisible decays of $K^0_S$.

hep-ex↗

arXiv2025

A ROOT based detector geometry and event visualization system for JUNO-TAO

The Taishan Antineutrino Observatory (TAO or JUNO-TAO) is a satellite experiment of Jiangmen Underground Neutrino Observatory (JUNO) and located near the Taishan nuclear power plant (NPP). TAO will measure the energy spectrum of reactor antineutrinos with unprecedented precision, which will benefit both reactor neutrino physics and the nuclear database. A detector geometry and event visualization system has been developed for TAO. The software is based on ROOT packages and embedded in the TAO offline software framework. It provides an intuitive tool to visualize the detector geometry, tune the reconstruction algorithm, understand the neutrino physics, and monitor the operation of reactors at NPP. The further applications of the visualization system in the experimental operation of TAO and its future development are also discussed.

physics.ins-det↗

arXiv2024

Study of charged Lepton Flavor Violation in electron muon interactions

With the improvement of muon acceleration technology, it has received great interest to exploit high-energy muon beams for collision or target experiments. We investigate possible charged Lepton Flavor Violation (cLFV) processes mediated by an extra massive neutral gauge boson Zprime in electron muon interactions, either at a proposed electron muon collider or in a fixed target experiment with high-energy muon beam hitting electrons in the target. Based on Monte Carlo calculations and fast detector simulations, we study in detail our signal and possible backgrounds, giving the sensitivity results of cLFV signals at the 90% confidence level. Compared with current and prospective limits set by other experiments, electron muon interactions demonstrate significant advantages in the cLFV coupling strength sensitivity with tau in the final states. In addition, a special cLFV coupling combination, lambda_emu * lambda_mumu, can also be probed in our proposal.

hep-ex↗

arXiv2024

Method for detector description conversion from DD4hep to Filmbox

DD4hep serves as a generic detector description toolkit recommended for offline software development in next-generation high-energy physics~(HEP) experiments. Conversely, Filmbox~(FBX) stands out as a widely used 3D modeling file format within the 3D software industry. In this paper, we introduce a novel method that can automatically convert complex HEP detector geometries from DD4hep description into 3D models in the FBX format. The feasibility of this method was demonstrated by its application to the DD4hep description of the Compact Linear Collider detector and several sub-detectors of the super Tau-Charm facility and circular electron-positron collider experiments. The automatic DD4hep--FBX detector conversion interface provides convenience for further development of applications, such as detector design, simulation, visualization, data monitoring, and outreach, in HEP experiments.

physics.ins-det↗

arXiv2024

Search for R-Parity-Violation-Induced Charged Lepton Flavor Violation at Future Lepton Colliders

Interest in searches for Charged Lepton Flavor Violation (CLFV) has continued in the past few decades since the observation of CLFV will indicate new physics beyond the Standard Model (BSM). As several future lepton colliders with high luminosity have been proposed, the search for CLFV will reach an unprecedented level of precision. Many BSM models allow CLFV processes at the tree level, such as the R-parity-violating (RPV) Minimal Supersymmetric Standard Model (MSSM), which is a good choice for benchmark. In this paper, we perform a detailed fast Monte Carlo simulation study on RPV-induced CLFV processes at future lepton colliders, including a 240 GeV circular electron positron collider (CEPC) and a 6 or 14 TeV muon collider. As a result, we found that the upper limits on the $τ$ related RPV couplings will be significantly improved, while several new limits on RPV couplings can be set, which are inaccessible by low-energy experiments.

hep-ph↗

arXiv2024

Search for exotic physics at BESIII

Exotic physics typically encompasses two categories of exotic particles: ``dark" particles beyond the standard model and exotic hadrons within the extended standard model. We present a summary of the recent results on exotic particles at BESIII, which could play a crucial role in the study of exotic physics.

hep-ex↗

arXiv2024

Rare Charm Decays at BESIII

The rare and forbidden processes within the Standard Model offer an opportunity to explore potential new physics beyond the SM. We summarize the research method and the recent results of rare charm decays at BESIII based on the extensive data samples in the $τ-c$ energy region, many of which impose stringent constraints on the new physics.

hep-ex↗

arXiv2023

The physics case for neutrino-neutrino collisions

Addressing the mass origin and properties of neutrinos is of strong interest to particle physics, baryogenesis and cosmology. Popular explanations involve physics beyond the standard model, for example, the dimension-5 Weinberg operator or heavy Majorana neutrinos arising from ``seesaw'' models. The current best direct limits on the electron neutrino mass, derived from nuclei beta decay or neutrinoless double beta decay processes, are at the sub-electronvolt level. Here we propose a novel neutrino neutrino collider where the neutrino beam is generated from TeV scale muon decays. Such collisions can happen between either neutrinos and anti-neutrinos, or neutrinos and neutrinos. We find that with a tiny integrated luminosity of about $10^{-5}$/fb we can already expect to observe direct neutrino anti-neutrino annihilation, $ν\barν\rightarrow {\rm Z}$, which also opens the door to explore neutrino related resonances $ν\barν\rightarrow {\rm X}$. The low luminosity requirement can accommodate a relatively large emittance muon beam. Such a device would also allow for probing heavy Majorana neutrino and effective Majorana neutrino mass through $νν\rightarrow {\rm H H}$ to a competitive level, for both electron and muon types.

hep-ph↗

arXiv2023

Search for Charged Lepton Flavor Violation in $J/ψ$ decays at BESIII

The observation of any charged lepton flavor violation (CLFV) process would be a clear signal of new physics beyond the Standard Model. Various decay modes, including lepton ($μ, τ$) decays, pseudoscalar meson ($K,π$) decays, vector meson ($ϕ, J/ψ, Υ$) decays, and Higgs decays, have been explored to detect CLFV. Focusing on the search for CLFV at the $τ$-charm region, the results of the search for $J/ψ\to eτ/ eμ$ using the 10 billion $J/ψ$ events collected by the BESIII experiment are presented. The upper limits (ULs) at the 90$\%$ confidence level are $\mathcal{B}(J/ψ\to e^\pmτ^\mp)<7.5\times10^{-8}$ and $\mathcal{B}(J/ψ\to e^\pmμ^\mp)<4.5\times10^{-9}$, respectively. Improving the previously published limits by two orders of magnitudes, the results are the most stringent CLFV searches in heavy quarkonium system.

hep-ex↗