arXiv subjects

Yu-Chen Guo

Publications and source records attributed to Yu-Chen Guo.

At least 19 recordsLinked to original sources

arXiv2026

SMEFT-Pheno-Agent: a natural-language-driven AI agent for machine-learning-assisted Standard Model Effective Field Theory phenomenology

We present SMEFT-Pheno-Agent, a Python workflow guided by a natural-language AI agent to perform machine-learning-assisted Standard Model Effective Field Theory (SMEFT) phenomenology at high-energy colliders. The software coordinates twelve automated execution phases spanning configuration intake, environment validation, event generation, machine-learning selection, statistical inference, and final audit. At each phase boundary, the agent interprets natural-language intent to generate runnable parameter files and adapter invocations required for subsequent execution. Once the detector-level events are written, the agent automatically proposes key kinematic observables alongside candidate machine-learning algorithms suited to the specific data structure and analysis objectives. All numerical calculations are delegated strictly to validated domain tools, with MadGraph5_aMC@NLO, Pythia, Delphes generating collider simulations, and MLAnalysis extracting features. The agent cannot modify physical parameters outside the locked configuration, and all LLM-produced artifacts, including parameter files, observable choices, algorithm selections, and prose drafts, are documented in machine-readable phase manifests prior to execution. These manifests establish complete reproducibility and audit traceability for SMEFT phenomenology studies.

hep-ph↗

arXiv2026

LHC Mono-$W/Z$ Signatures as a Probe for Dark Matter Explanations of Astrophysical Excesses

The inert two-Higgs doublet model (IDM) is a compelling framework for weakly interacting massive particles (WIMPs) linked to electroweak symmetry breaking. It can account for both the Galactic Center gamma-ray excess (GCE) and the AMS-02 antiproton anomaly while also satisfying relic density and direct detection constraints for dark matter (DM) masses in the $55-75$ GeV range. Three specific DM annihilation channels can be identified: Higgs resonance, $SA$ co-annihilation, and $SS\to WW^{\ast}$ annihilation. Among these, the DM mass range of $70-75$ GeV with dominant $SS\to WW^{\ast}$ annihilation has received less attention in collider searches. To validate this parameter space, we combine LHC searches for mono-$W/Z$ signatures. In particular, we develop a channel-separation strategy to disentangle the contributions of charged mass splitting ($\Delta^{\pm}$) and neutral mass splitting ($\Delta^0$) in the inert scalar sector at the LHC. Our results indicate that most of the parameter space consistent with these astrophysical anomalies in the $SS\to WW^{\ast}$ annihilation regime will be testable at the High-Luminosity LHC. Specifically, from the leptonic channel we obtain a $2\sigma$ exclusion limit of $80 \lesssim \Delta^0 \lesssim 260$ GeV, while the hadronic channel yields $30 \lesssim \Delta^0 \lesssim 150$ GeV and $70 \lesssim \Delta^{\pm} \lesssim 230$ GeV for $m_S = 70$ GeV.

hep-ph↗

arXiv2026

A Low-Cost Teapot Effect Experiment for Introductory Physics

The teapot effect refers to the tendency of a poured liquid to cling to the lip of a container and run down the outside. It is a familiar but physically rich example of flow separation. We present a low-cost experiment for introductory physics laboratories that uses 3D-printed cups, a simple flow regulator, and basic surface treatments to explore this phenomenon in a classroom setting. Students measure the run-off length along the outer wall as an accessible indicator of sticking versus separation and use it to compare the effects of flow velocity and surface wettability. Rather than attempting a full quantitative test of research-level models, the activity is designed to illustrate the inertial-capillary picture of the teapot effect in a form that is experimentally straightforward and pedagogically effective. The experiment connects a familiar everyday observation to fluid inertia, wetting, and interfacial forces in a form that is well suited to introductory instruction.

physics.ed-ph↗

arXiv2026

Quantum Tomography of Fermion Pairs in $e^+e^-$ Collisions: Longitudinal Beam Polarization Effects

We present a quantum tomography study of fermion pair production at future $e^+e^-$ colliders, emphasizing how longitudinal beam polarization controls the two-qubit spin density matrix. We study the processes $e^+ e^- \to t\bar{t},\ e^+e^-\to \mu^+\mu^-$ and Bhabha scattering $e^+e^-\to e^+e^-$, representing the mass threshold behavior, the $Z$ pole resonance and the $s/t$-channel interplay. We choose to focus on three key concepts: quantum entanglement via the concurrence $\mathcal{C}$, Bell nonlocality via the optimal Clauser Horne Shimony Holt (CHSH) parameter $\mathcal{B}$, and non-stabilizerness (``magic'') via the second stabilizer R\'enyi entropy $\mathcal{M}_2$. For the $s$-channel-dominated channels, longitudinal polarization mainly reshapes single-spin polarizations while leaving the spin-correlation matrix largely unchanged, rendering $\mathcal{C}$ and $\mathcal{B}$ comparatively robust, but inducing a pronounced variation of $\mathcal{M}_2$. In contrast, in Bhabha scattering, polarization modifies the relative contributions of the $s$-channel and $t$-channel and can strongly affect all three observables. The observability of entanglement, Bell nonlocality, and magic exceeds the $5\sigma$ level when both statistical and systematic uncertainties are included, establishing the fermion pair systems as ideal laboratories for quantum-information studies in high energy leptonic collisions. With optimized beam polarization, future $e^+e^-$ colliders will provide a unique opportunity to experimentally explore and influence quantum resources in particle interactions.

hep-ph↗

arXiv2025

Muon collider probes of the gluonic quartic gauge couplings

We investigate the dimension-8 gluonic quartic gauge couplings (gQGCs) at future high-energy muon colliders through the process $\mu^{+}\mu^{-}\!\to gg\gamma$. Using detailed event simulation and optimized kinematic selections, we derive projected sensitivities to the Wilson coefficients and their associated new-physics scales, showing that muon colliders can probe deep into the multi-TeV regime and significantly surpass current LHC bounds. We further present the positivity bounds on those Wilson coefficients, as theoretical constraints from the fundamental principles of quantum field theory. Our results establish $\mu^{+}\mu^{-}\!\to gg\gamma$ as one of the most sensitive probes of dimension-8 new physics at future muon colliders.

hep-ph↗

arXiv2025

New Physics Search at the CEPC: a General Perspective

The Circular Electron-Positron Collider (CEPC), a proposed next-generation Higgs factory, provides new opportunities to explore physics beyond the Standard Model (SM). With its clean electron-positron collision environment and the ability to collect large samples of Higgs, W, and Z bosons, the CEPC enables precision measurements and searches for new physics. This white paper outlines the CEPC's discovery potential, including studies of exotic decays of the Higgs, Z, and top quarks, dark matter and dark sector phenomena, long-lived particles, supersymmetry, and neutrino-related signatures. Advanced detector technologies and reconstruction techniques, such as one-to-one correspondence reconstruction and jet origin identification, significantly improve sensitivity to rare and weakly interacting processes. The CEPC is particularly well suited to probe the electroweak phase transition and test models of electroweak baryogenesis and dark sector interactions. In addition, global fit analyses highlight the CEPC's complementary role in constraining a wide range of new physics scenarios. These features position the CEPC as a powerful tool for exploring the next frontier in fundamental particle physics in the post-Higgs discovery era.

hep-ex↗

arXiv2025

Search for anomalous quartic gauge couplings in the process $\mu^+\mu^-\to \bar{\nu}\nu\gamma\gamma$ with a nested local outlier factor

In recent years, with the increasing luminosities of colliders, handling the growing amount of data has become a major challenge for future new physics~(NP) phenomenological research. To improve efficiency, machine learning algorithms have been introduced into the field of high-energy physics. As a machine learning algorithm, the local outlier factor~(LOF), and the nested LOF~(NLOF) are potential tools for NP phenomenological studies. In this work, the possibility of searching for the signals of anomalous quartic gauge couplings~(aQGCs) at muon colliders using the NLOF is investigated. Taking the process $\mu^+\mu^-\to \nu\bar{\nu}\gamma\gamma$ as an example, the signals of dimension-8 aQGCs are studied, expected coefficient constraints are presented. The event selection strategy uses unsupervised anomaly scores, with supervised optimization for EFT sensitivity. The NLOF algorithm is shown to outperform the k-means based anomaly detection methods, and a traditional counterpart.

hep-ph↗

arXiv2024

Search for Neutral Triple Gauge Couplings with $ZZ$ Production at Future Electron Positron Colliders

This study investigates Neutral Triple Gauge Couplings (nTGCs) through $ZZ$ production at future electron-positron colliders. The impact of beam polarization on cross section is analyzed. We compare the signals and backgrounds for five different $ZZ$ decay channels and present our event selection strategies for future $e^+e^-$ colliders. The expected coefficient constraints for each decay channels are provided, and final expected constraints are derived by combining results from the different decay patterns. Our analysis indicates that future electron-positron colliders will have significantly enhanced detection capabilities for nTGCs compared to the current LHC experiments, with expected improvements in constraints by one to two orders of magnitude.

hep-ph↗

arXiv2024

Using k-means assistant event selection strategy to study anomalous quartic gauge couplings at muon colliders

The search for new physics beyond the Standard Model is one of the central problems of current high energy physics interest. As the luminosities of current and near-future colliders continue to increase, the search for new physics has increased the requirements for processing large amounts of data. Meanwhile, quantum computing which is rapidly evolving, has great potential to become a powerful tool to help search for new physics signals. Since the k-means algorithm is known to be able to be accelerated with the help of quantum computing, we investigate and propose an event selection strategy based on k-means algorithm to search for new physics signals. Taking the case of tri-photon processes at the muon colliders as an example, the event selection strategy is shown to be effective in helping to search for the signals of dimension-8 operators contributing to anomalous quartic gauge couplings. Compared with traditional event selection strategy, the expected constraints are generally tighter.

hep-ph↗

arXiv2023

Optimize the event selection strategy to study the anomalous quartic gauge couplings at muon colliders using the support vector machine and quantum support vector machine

The search of the new physics~(NP) beyond the Standard Model is one of the most important topics in current high energy physics. With the increasing luminosities at the colliders, the search for NP signals requires the analysis of more and more data, and the efficiency in data processing becomes particularly important. As a machine learning algorithm, support vector machine~(SVM) is expected to to be useful in the search of NP. Meanwhile, the quantum computing has the potential to offer huge advantages when dealing with large amounts of data, which suggests that quantum SVM~(QSVM) is a potential tool in future phenomenological studies of the NP. How to use SVM and QSVM to optimize event selection strategies to search for NP signals are studied in this paper. Taking the tri-photon process at a muon collider as an example, it can be shown that the event selection strategies optimized by the SVM and QSVM are effective in the search of the dimension-8 operators contributing to the anomalous quartic gauge couplings.

hep-ph↗

arXiv2023

Study of the gluonic quartic gauge couplings at muon colliders

The potential of the muon colliders open up new possibilities for the exploration of new physics beyond the Standard Model. It is worthwhile to investigate whether muon colliders are suitable for studying gluonic quartic gauge couplings~(gQGCs), which can be contributed by dimension-8 operators in the framework of the Standard Model effective field theory, and are intensively studied recently. In this paper, we study the sensitivity of the process $μ^+μ^-\to j j ν\barν$ to gQGCs. Our result indicate that the muon colliders with c.m. energies larger than $4\;{\rm TeV}$ can be more sensitive to gQGCs than the Large Hadron Collider.

hep-ph↗

arXiv2023

Tri-photon at muon collider: a new process to probe the anomalous quartic gauge couplings

The muon collider has recently received a great deal of attention because of its ability to achieve both high energy and high luminosity. It plays as a gauge boson collider because the vector boson scattering (VBS) becomes the dominant production topology for Standard Model processes starting from a few TeV of collision energy. In this paper, we propose that the process of $μ^+μ^-$ annihilation into tri-photon is also very sensitive to the search of anomalous quartic gauge couplings (aQGCs). We investigate the projected constraints on the transverse operators contributing to aQGCs through $μ^+μ^-\to Z^\ast/γ^\ast\to γγγ$ at muon colliders. For the muon collider with $\sqrt{s}=3$ TeV and $\mathcal{L}=1\;{\rm ab}^{-1}$, the expected constraints are about two orders of magnitude stronger than those at the 13 TeV LHC.

hep-ph↗

arXiv2023

Extract the energy scale of anomalous $γγ\to W^+W^-$ scattering in the vector boson scattering process using artificial neural networks

As a model independent approach to search for the signals of new physics~(NP) beyond the Standard Model~(SM), the SM effective field theory~(SMEFT) draws a lot of attention recently. The energy scale of a process is an important parameter in the study of an EFT such as the SMEFT. However, for the processes at a hadron collider with neutrinos in the final states, the energy scales are difficult to reconstruct. In this paper, we study the energy scale of anomalous $γγ\to W^+W^-$ scattering in the vector boson scattering~(VBS) process $pp\to j j \ell^+\ell^-ν\barν$ at the large hadron collider~(LHC) using artificial neural networks~(ANNs). We find that the ANN is a powerful tool to reconstruct the energy scale of $γγ\to W^+W^-$ scattering. The factors affecting the effects of ANNs are also studied. In addition, we make an attempt to interpret the ANN and arrive at an approximate formula which has only five fitting parameters and works much better than the approximation derived from kinematic analysis. With the help of ANN approach, the unitarity bound is applied as a cut on the energy scale of $γγ\to W^+W^-$ scattering, which is found to has a significant suppressive effect on signal events. The sensitivity of the process $pp\to j j \ell^+\ell^-ν\barν$ to anomalous $γγWW$ couplings and the expected constraints on the coefficients at current and possible future LHC are also studied.

hep-ph↗

arXiv2023

Measuring the anomalous quartic gauge couplings in the $W^+W^-\to W^+W^-$ process at muon collider using artificial neural networks

The muon collider provides a unique opportunity to study the vector boson scattering processes and dimension-8 operators contributing to anomalous quartic gauge couplings~(aQGCs). Because of the cleaner final state, it is easier to decode subprocess and certain operator couplings at a muon collider. We attempt to identify the anomalous $WWWW$ coupling in the exclusive $WW\to WW$ scattering in this paper. Since one aQGC can be induced by multiple dimension-8 operators, the study of one coupling can help to confine different operators. Meanwhile, singling out the $WW\to WW$ process can help to study the unitarity bounds. The vector boson scattering process corresponding to the anomalous $WWWW$ coupling is $μ^+μ^-\to νν\barν\barν\ell^+\ell^-$, with four (anti-)neutrinos in the final state, which brings troubles in phenomenological studies. In this paper, the machine learning method is used to tackle this problem. We find that, using the artificial neural network can extract the $W^+W^-\to W^+W^-$ contribution, and is helpful to reconstruct the center of mass energy of the subprocess which is important in the study of the Standard Model effective field theory. The sensitivities and the expected constraints on the dimension-8 operators at the muon collider with $\sqrt{s}=30$ TeV are presented. We demonstrate that the artificial neural networks exhibit great potential in the phenomenological study of processes with multiple neutrinos in the final state.

hep-ph↗

arXiv2023

Constraints on anomalous quartic gauge couplings by $γγ\to W^+W^-$ scattering

The vector boson scattering (VBS) processes in Large Hadron Collider (LHC) experiments offer a unique opportunity to probe the anomalous quartic gauge couplings (aQGCs). We study the dimension-8 operators contributing to the anomalous $γγWW$ coupling and the corresponding unitarity bounds via the exclusive $γγ\to W^+W^-$ production in $pp$ collisions at LHC for a center of mass energy of $\sqrt{s}=13$ TeV. By analysing the kinematical features of the signal, we propose an event selection strategy to highlight the aQGC contributions. Based on the event selection strategy, the statistical significance of the signals are analyzed in detail, and the constraints on the coefficients of the anomalous quartic gauge operators are obtained.

hep-ph↗

arXiv2023

The study of neutral triple gauge couplings in the process $e^+e^-\to Zγ$ including unitarity bounds

The neutral triple gauge couplings~(nTGCs) provide a unique opportunity to probe new physics beyond the Standard Model. The nTGCs can be described by an effective field theory~(EFT), which is valid only under a certain energy scale. One of the signatures that an EFT is no longer valid is the violation of unitarity. We study the partial wave unitarity bounds on the coefficients of nTGCs in the process $e^+e^-\to Zγ$. In the experiments, the constraints obtained should be tighter than the unitarity bounds, otherwise the results are meaningless, therefore there exists a minimal luminosity for a $e^+e^-$ collider such as the CEPC to study the nTGCs. To derive the minimal luminosity, the kinematic features and event selection strategy are studied by Monte-Carlo simulation. Both the processes $e^+e^-\to \ell^+\ell^-γ$ and $e^+e^-\to jjγ$ are studied, event selection strategies are discussed. Based on the statistical significance, the expected constraints in experiments are estimated. The required luminosities for the experiments to reach the unitarity bounds are presented.

hep-ph↗

arXiv2023

Using a nested anomaly detection machine learning algorithm to study the neutral triple gauge couplings at an \texorpdfstring{$e^+e^-$}{e+e-} collider

Anomaly detection algorithms have been proved to be useful in the search of new physics beyond the Standard Model. However, a prerequisite for using an anomaly detection algorithm is that the signal to be sought is indeed anomalous. This does not always hold true, for example when interference between new physics and the Standard Model becomes important. In this case, the search of new physics is no longer an anomaly detection. To overcome this difficulty, we propose a nested anomaly detection algorithm, which appears to be useful in the study of neutral triple gauge couplings at the CEPC, the ILC and the FCC-ee. Our approach inherits the advantages of the anomaly detection algorithm been nested, while at the same time, it is no longer an anomaly detection algorithm. As a complement to anomaly detection algorithms, it can achieve better results on problems that are no longer anomaly detection.

hep-ph↗

arXiv2023

Shining light on magnetic monopoles through high-energy muon colliders

The search for magnetic monopoles has been a longstanding concern of the physics community for nearly a century. However, up to now, the existence of elementary magnetic monopoles remains an open question. The electroweak 't Hooft-Polyakov monopoles have been predicted with mass at the order of 10 TeV. This mass scale is unreachable at current colliders. Recently, the muon colliders have gained much attention in the community due to technological developments. The advantages of the muon beam encourage us to raise the high-energy option and consider the high-energy muon collider as a unique opportunity to search for magnetic monopoles. This letter discusses the production of magnetic monopoles via the annihilation process and proposes the search for magnetic monopoles at future high-energy muon colliders.

hep-ph↗