SearcharxivSearch

arXiv subjects

Yong Ban

Publications and source records attributed to Yong Ban.

13 recordsLinked to original sources

Agentic Hybrid RAG for Evidence-Grounded Muon Collider Analysis

Muon collider research spans accelerator physics, detector instrumentation, and high-energy phenomenology, with relevant evidence scattered across a rapidly expanding and heterogeneous body of scientific literature. As high-energy physics (HEP) increasingly explores agent-assisted analysis workflows, efficiently locating, integrating, and verifying scientific evidence becomes an essential capability. While retrieval-augmented generation (RAG) offers a promising framework for scientific question answering, integrating agentic reasoning without compromising retrieval precision remains a key challenge. In this work, we present agentic hybrid RAG, an evidence-grounded RAG framework for muon collider research. The framework combines a hybrid retriever, integrating sparse lexical and dense semantic retrieval, with an agentic reasoning module for query decomposition, evidence expansion, and grounded answer generation. To enable systematic evaluation, we construct the first benchmark for retrieval-augmented scientific question answering in the muon collider domain, comprising a curated literature corpus together with dedicated retrieval and answer-generation benchmarks covering major detector and physics research topics. Extensive evaluation shows that hybrid retrieval provides the strongest retrieval backbone, while agentic reasoning is most effective for controlled evidence expansion and answer synthesis. Built on this principle, agentic hybrid RAG consistently outperforms representative retrieval and RAG baselines in retrieval effectiveness, answer quality, evidence coverage, and factual grounding. Together, the benchmark and framework provide a foundation for evidence-grounded scientific question answering and future HEP analysis agents operating over large-scale scientific literature.

hep-ex

Probing Cosmic Ray Composition and Muon-philic Dark Matter via Muon Tomography

This work presents a novel cosmic-ray scattering experiment employing a Resistive Plate Chambers (RPC) muon tomography system. By introducing the scattering angle between incident and outgoing cosmic-ray tracks as a key observable, this approach enables simultaneous studies of secondary cosmic-ray composition and searching for new physics. During a 63-day campaign, 1.18 million cosmic ray scattering events were recorded and analyzed. By performing combined template fits to the observed angular distribution, particle abundances are measured -- for example, resolving the electron component at $\sim 2\%$ precision. Furthermore, constraints are established on elastic muon dark matter (DM) scattering cross-sections for muon-philic dark matter. At the $95\%$ confidence level, the limit reaches 1.61 $\times$ $10^{-17}$ $\rm{cm}^{2}$ for 1 GeV slow DM, demonstrating sensitivity limit to light muon-coupled slow DM, in scenarios where a strongly interacting dark matter component is captured and thermalized within the Earth, leading to large surface densities.

hep-ex

Revealing Secondary Particle Signatures in Muography Based on the Point of Closest Approach Algorithm

This work reinterprets so-called 'noise' in cosmic ray imaging, indicating that the data of reconstructed Points of Closest Approach (PoCA points) outside the volume of interest defined by traditional tomography methods contain valuable physical information that has been traditionally disregarded. Through analysis of data from the detection system of four resistive plate chambers (RPCs) and Monte Carlo simulations employing energy deposition weighting for coordinate determination, we confirm that these points physically originate from the interaction between muons and the material above the detection system, particularly the roof, resulting in the production of secondary particles. The research yields two principal findings: first, in the four-layer compliance measurement system, the position recording of the first layer can be from secondary particles generated by cosmic rays, while the records from the three layers below represent the actual trajectories of cosmic rays; second, the roof structure significantly impacts the distribution of PoCA points at detector positions, where quantitative analysis demonstrates a strong correlation between roof thickness and the number of reconstructed PoCA points -- a relationship that can be precisely measured through $z$-coordinate distribution analysis in specific intervals. Due to the varying performances of different roofing materials in this analytical method, this approach holds significant potential for development into a new tomography technique.

hep-ex

Probing triple Higgs production via $4\tau 2b$ decay channel at a 100 TeV hadron collider

A comprehensive study of triple Higgs boson production in the $4\tau 2b$ decay final state is performed for the first time at a future 100 TeV hadron collider. The analysis incorporates modified Higgs self-couplings via trilinear Higgs self-coupling $c_3$ and quartic Higgs self-coupling $d_4$, enabling for a model-independent investigation of potential new physics effects. Higgs bosons are reconstructed using both resolved and boosted techniques. To optimize sensitivity across different kinematic regions, we introduce a novel event categorization strategy based on the triple Higgs invariant mass spectrum and the multiplicity of boosted Higgs bosons. In addition to a traditional cut-based analysis, a Boosted Decision Tree (BDT) approach is employed to exploit multivariate correlations among kinematic observables, leading to a significant improvement in sensitivity. Our result demonstrates that the $4\tau 2b$ channel provides a viable pathway for probing the Higgs quartic coupling, complementing the existing multi-Higgs production studies, and could reach 5 $\sigma$ in significance for $c_3 \lesssim -1$ and $d_4 \gtrsim 10$ in the scanned range.

hep-ph

Testing Bell inequalities and probing quantum entanglement at CEPC

We study quantum entanglement and test violation of Bell-type inequality at the Circular Electron Positron Collider (CEPC), which is one of the most attractive future colliders. It's a promising particle collider designed to search new physics, make Standard Model (SM) precision measurements, and serving as a Higgs factory. Our study is based on a fast simulation of the $Z$ boson pair production from Higgs boson decay at $\sqrt{s} = 250$ GeV. The detector effects are also included in the simulation. The spin density matrix of the joint $ZZ$ system is parametrized using irreducible tensor operators and reconstructed from the spherical coordinates of the decay leptons. To test Bell inequalities, we construct observable quantities for the $H \to ZZ*$ process in CEPC by using the (Collins-Gisin-Linden-Massar-Popescu) CGLMP inequality, whose value is determined from the density matrix of the Z boson pairs. The sensitivity of the Bell inequality violation is observed with more than 1$\sigma$ and the presence of the quantum entanglement is probed with more than 2$\sigma$ confidence level.

hep-ph

Searches for multi-Z boson productions and anomalous gauge boson couplings at a muon collider

Multi-boson productions can be exploited as novel probes either for standard model precision tests or new physics searches, and have become one of those popular topics in the ongoing LHC experiments, and in future collider studies, including those for electron-positron and muon-muon colliders. Here we focus on two examples, i.e., ZZZ direct productions through $\mu^{+}\mu^{-}$ annihilation at a 1 TeV muon collider, and ZZ productions through vector boson scattering at a 10 TeV muon collider, with an integrated luminosity of $10 \, \text{ab}^{-1}$. Various channels are considered, including, such as $ZZZ \rightarrow 4l2\nu$ and $ZZZ \rightarrow 4l + 2 \text{ jets}$, etc. Expected significance on these multi-Z boson production processes are provided based on a detailed Monte Carlo study and signal background analysis. Sensitives on anomalous gauge boson couplings are also presented.

hep-ex

A proposed PKU-Muon experiment for muon tomography and dark matter search

We propose here a set of new methods to directly detect light mass dark matter through its scattering with abundant atmospheric muons or accelerator beams. Firstly, we plan to use the free cosmic-ray muons interacting with dark matter in a volume surrounded by tracking detectors, to trace possible interaction between dark matter and muons. Secondly, we will interface our device with domestic or international muon beams. Due to much larger muon intensity and focused beam, we anticipate the detector can be made further compact and the resulting sensitivity on dark matter searches will be improved. Furthermore, we will measure precisely directional distributions of cosmic-ray muons, either at mountain or sea level, and the differences may reveal possible information of dark matter distributed near the earth. Specifically, our methods can have advantages over `exotic' dark matters which are either muon-philic or slowed down due to some mechanism, and sensitivity on dark matter and muon scattering cross section can reach as low as microbarn level.

hep-ex

Probing darK Matter Using free leptONs: PKMUON

We propose a new method to detect sub-GeV dark matter, through their scatterings from free leptons and the resulting kinematic shifts. Specially, such an experiment can detect dark matter interacting solely with muons. The experiment proposed here is to directly probe muon-philic dark matter, in a model-independent way. Its complementarity with the muon on target proposal, is similar to, e.g. XENON/PandaX and ATLAS/CMS on dark matter searches. Moreover, our proposal can work better for relatively heavy dark matter such as in the sub-GeV region. We start with a small device of a size around 0.1 to 1 meter, using atmospheric muons to set up a prototype. Within only one year of operation, the sensitivity on cross section of dark matter scattering with muons can already reach $σ_D\sim 10^{-19 (-20,\,-18)}\rm{cm}^{2}$ for a dark mater $\rm{M_D}=100\, (10,\,1000)$ MeV. We can then interface the device with a high intensity muon beam of $10^{12}$/bunch. Within one year, the sensitivity can reach $σ_D\sim 10^{-27 (-28,\,-26)}\rm{cm}^{2}$ for $\rm{M_D}=100\, (10,\,1000)$ MeV.

hep-ph

Searching for Majorana Neutrinos at a Same-Sign Muon Collider

Majorana properties of neutrinos have long been a focus in the pursuit of possible new physics beyond the standard model, which has motivated lots of dedicated theoretical and experimental studies. A future same-sign muon collider is an ideal platform to search for Majorana neutrinos through the Lepton Number Violation process. Specifically, this t-channel kind of process is less kinematically suppressed and has a good advantage in probing Majorana neutrinos at high mass regions up to 10 TeV. In this paper, we perform a detailed fast Monte Carlo simulation study through examining three different final states: 1) pure-leptonic state with electrons or muons, 2) semi-leptonic state, and 3) pure-hadronic state in the resolved or merged categories. Furthermore, we perform a full simulation study on the pure-leptonic final state to validate our fast simulation results.

hep-ph

Search for the Higgs boson pair production in the $b\bar{b}μ^+μ^-$ final state at the LHC

The Higgs boson pair production via gluon-gluon fusion and vector boson fusion in the $b\bar{b}μ^+μ^-$ final state at the LHC is studied to probe the Higgs self-coupling $κ_λ$ and the four-boson HHVV coupling $κ_{\rm{2V}}$ for the first time. A cut-based analysis and a machine learning analysis using boosted decision trees are performed with categorizations and optimizations depending on the variations of these couplings. The expected sensitivities are extracted with different integrated luminosities assumed up to the full HL-LHC runs. The expected upper limit at 95\% confidence level on the HH production is calculated as 47 (28) times the Standard Model cross-section using the cut-based method (boosted decision trees) for the gluon-gluon fusion production, and 928 for the vector boson fusion production, assuming an integrated luminosity of 3000 fb$^{-1}$. The expected constraints on the couplings at 95\% confidence level are calculated to be $-13.8< κ_λ< 19.1$ ($-10.0< κ_λ< 15.5$) and $-3.4< κ_{\rm{2V}}< 5.5$ using the cut-based method (boosted decision trees), respectively, assuming an integrated luminosity of 3000 fb$^{-1}$.

hep-ph

Cross Section and Higgs Mass Measurement with Higgsstrahlung at the CEPC

The Circular Electron Positron Collider (CEPC) is a future Higgs factory proposed by the Chinese high energy physics community. It will operate at a center-of-mass energy of 240-250 GeV. The CEPC will accumulate an integrated luminosity of 5 ab$^{\rm{-1}}$ in ten years' operation, producing one million Higgs bosons via the Higgsstrahlung and vector boson fusion processes. This sample allows a percent or even sub-percent level determination of the Higgs boson couplings. With GEANT4-based full simulation and dedicated fast simulation tool, we evaluated the statistical precisions of the Higgstrahlung cross section $σ_{ZH}$ and the Higgs mass $m_{H}$ measurement at the CEPC in the $Z\rightarrowμ^+μ^-$ channel. The statistical precision of $σ_{ZH}$ ($m_{H}$) measurement could reach 0.97\% (6.9 MeV) in the model-independent analysis which uses only the information of Z boson decay. For the standard model Higgs boson, the $m_{H}$ precision could be improved to 5.4 MeV by including the information of Higgs decays. Impact of the TPC size to these measurements is investigated. In addition, we studied the prospect of measuring the Higgs boson decaying into invisible final states at the CEPC. With the standard model $ZH$ production rate, the upper limit of ${\cal B}(H\rightarrow \rm{inv.})$ could reach 1.2\% at 95\% confidence level.

hep-ex

$ρ- ω$ Mixing in $J/ψ\to VP$ Decays

The study on $ρ-ω$ mixing is mainly focused on vector mesons decay with isospin I=1, namely $ρ(ω)\toπ^+π^-$ process. In this paper, we present the study of $ρ-ω$ mixing in $ρ(ω)\toπ^+π^-π^0$ (I=0) using a flavor parameterization model for $J/ψ\to VP$ process. By fitting theoretical frame to PDG data, we obtain the SU(3)-breaking effect parameters $s_V=0.03\pm 0.12,\ s_P=0.17\pm 0.17$ and the $ρ-ω$ mixing polarization operator $Π_{ρω}=0.006\pm 0.011\text{\text{GeV}}^2$. The branching ratios are also renewed when mixing effect is incorporated: $Br(J/ψ\to ωπ^0) = (3.64 \pm 0.37)\times 10^{-4}$, $Br(J/ψ\to ωη) = (1.48 \pm 0.17)\times 10^{-3}$, $Br(J/ψ\to ωη^{\prime}) = (1.55\pm 0.56)\times 10^{-4}$; they are different from the corresponding PDG2012 values by 19%, 15% and 15%, respectively.

hep-ph

Probing New Physics via pp-> W+W- -> lvjj at the CERN LHC

TeV scale new Physics, e.g., Large Extra Dimensions or Models with anomalous triple vector boson couplings, can lead to excesses in various kinematic regions on the semi-leptonic productions of pp -> WW -> lvjj at the CERN LHC, which, although suffers from large QCD background compared with the pure leptonic channel, can benefit from larger production rates and the reconstructable 4-body mass Mlvjj. We study the search sensitivity through the lvjj channel at the 7TeV LHC on relevant new physics, via probing the hard tails on the reconstructed Mlvjj and the transverse momentum of W-boson (PTW), taking into account main backgrounds and including the parton shower and detector simulation effects. Our results show that with integrated luminosity of 5fb-1, the LHC can already discovery or exclude a large parameter region of the new physics, e.g., 95% CL. limit can be set on the Large Extra Dimensions with a cut-off scale up to 1.5 TeV, and the WWZ anomalous coupling down to, e.g. |λ_Z|~0.1. Brief results are also given for the 8TeV LHC.

hep-ph