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Y. Li

Publications and source records attributed to Y. Li.

At least 55 records · Page 3Linked to original sources

Scintillation light calibrations, systematic uncertainties, and triggering efficiency in the MicroBooNE detector

Scintillation light, produced alongside ionisation charge from particle interactions, plays a critical role in liquid argon time projection chamber (LArTPC) detectors. A detailed understanding of its production and detection mechanisms is essential for robust calibration, systematic uncertainty evaluation, and physics analysis. This article describes the MicroBooNE light simulation, light-based triggering schemes, photomultiplier tube gain calibration, light response stability, and light-based systematic uncertainties over the course of five years of data collection. In addition, we present a measurement of scintillation light triggering efficiency, focusing on the lowest-light regime relevant to rare-event searches and low-energy neutrino interactions. Finally, we discuss two notable observations in MicroBooNE's data, both reported here for the first time: an approximately 50% decline in MicroBooNE's light yield over time, concentrated in the first two years of running; and a higher than expected O(200 kHz) rate of single photoelectron noise. The results presented provide an important benchmark of long-term light detection performance in LArTPC neutrino detectors.

physics.ins-det↗

SPT-3G D1: Maps of the millimeter-wave sky from 2019 and 2020 observations of the SPT-3G Main field

Maps of the sky in millimeter wavelengths contain rich information on cosmology through anisotropies of the cosmic microwave background (CMB). Creating multifrequency sky maps of anisotropies in the $I$, $Q$, and $U$ Stokes parameters is one of the first steps of CMB cosmology analyses. In this work, we describe the production and validation of a set of sky maps from the South Pole Telescope's third-generation camera, SPT-3G. The maps are from data taken in frequency bands centered at 95, 150, and 220 GHz and taken during the first two years, 2019 and 2020, of the SPT-3G Main survey, which covers $4\%$ of the sky. We applied high-pass filters to time series of individual detectors and binned the filtered time series samples into map pixels. After that, we calibrated and cleaned the maps to reduce known systematic errors. In addition, we searched for other systematic errors through null tests and mitigated a significant systematic error detected therein. The white noise levels of the full-depth maps of the $I$ Stokes parameter are $5.4$, $4.4$, and $16.2$ $\mathrm{μK}$-$\mathrm{arcmin}$ in the 95, 150, and 220 GHz bands, respectively, and $8.4$, $6.6$, and $25.8$ $\mathrm{μK}$-$\mathrm{arcmin}$ for $Q/U$. These maps are the deepest to date used for measurements of mid-to-high-$\ell$ primary temperature and $E$-mode polarization CMB anisotropies, and reconstructions of the CMB gravitational lensing potential. We make these maps and supporting data products publicly accessible.

astro-ph.CO↗

Breathing and Fission of Magnetic Multi-Solitons

We report the deterministic experimental realization and controlled fission of magnetic multi-soliton states in a uniform quasi-one-dimensional immiscible two-component Bose gas. We explore the Manakov regime, where the spin dynamics is well described by the easy-axis Landau-Lifshitz equation (LLE). The gauge equivalence between the easy-axis LLE and the attractive nonlinear Schrödinger equation (NLSE) enables the direct construction of magnetic multi-solitons from the well-known NLSE solutions. We observe the two- and three- soliton states, which exhibit robust breathing in quantitative agreement with integrable theory. By introducing a weak, localized perturbation, we controllably break integrability and induce the splitting of a two-soliton into its fundamental constituents. This process reveals the composite structure of multi-soliton states and realizes an experimental analog of the inverse scattering transform.

cond-mat.quant-gas↗

Measurements of differential charged-current cross sections on argon for electron neutrinos with final-state protons in MicroBooNE

This work presents single-differential electron-neutrino charged-current cross sections on argon measured using the MicroBooNE detector at the Fermi National Accelerator Laboratory. The analysis uses data recorded when the Neutrinos at the Main Injector beam was operating in both neutrino and antineutrino modes, with exposures of $2 \times 10^{20}$ and $5 \times 10^{20}$ protons on target, respectively. A selection algorithm targeting electron-neutrino charged-current interactions with at least one proton, one electron, and no pions in the final topology is used to measure differential cross sections as a function of outgoing electron energy, total visible energy, and opening angle between the electron and the most energetic proton. The interaction rate as a function of proton multiplicity is also reported. The total cross section is measured as [4.1 $\pm$ 0.3 (stat.) $\pm$ 1.1 (syst.)]$ $$\times 10^{-39} \mathrm{cm}^{2}/ \mathrm{nucleon}$. The unfolded cross-section measurements are compared to predictions from neutrino event generators commonly employed in the field. Good agreement is seen across all variables within uncertainties.

hep-ex↗

Sustainability Assessment of Future Accelerators

The Large Particle Physics Laboratory Directors Group (LDG) established the Working Group (WG) on the Sustainability Assessment of Future Accelerators in 2024 with the mandate to develop guidelines and a list of key parameters for the assessment of the sustainability of future accelerators in particle physics. While focused on accelerator projects, much of the work will also be relevant to other present and upcoming research infrastructures. The development and continuous update of such a framework aim to enable a coherent communication amongst scientists and adequately convey the information to a broader set of stakeholders. This document outlines the key findings and recommendations of the LDG Sustainability WG and provides a summary of current best practices aimed at enabling sustainable accelerator-based research infrastructures. Not all sustainability topics are addressed at the same level. The assessment process is complex, largely under development and a homogeneous evaluation of all the aspects requires a strategy to be developed and implemented over time.

physics.acc-ph↗

Polarization-Multiplexed Chaotic LiDAR Based on a VCSEL with Delayed Orthogonal Feedback

Light detection and ranging (LiDAR) systems are pivotal for precise distance and velocity measurement, yet widespread deployment requires solutions that balance their performance, robustness, and simplicity. Here, we propose a novel chaotic LiDAR system based on a semiconductor vertical-cavity surface-emitting laser (VCSEL) with delayed orthogonal polarization feedback. By exploiting the intrinsic competition between the transverse electric (TE) and transverse magnetic (TM) modes, the system generates a polarization-multiplexed dynamics: a chaotic TM mode serves as the reference, while a feedback-modulated TE mode probes the target. This all-in-one source eliminates the need for external optical modulators or complex coherent detection. The system's dynamics is finely tunable via a half-wave ($λ$/2) plate in the feedback loop and the laser injection current, enabling real-time optimization of the cross-correlation signal-to-noise ratio. Experimental results demonstrate precise linear ranging with a resolution of approximately 1.2 cm. Furthermore, the system exhibits strong inherent resistance to external optical interference, maintaining accurate ranging even in the presence of a secondary laser source. This compact, tunable, and interference-resilient platform offers a promising pathway toward low-cost, high-performance LiDAR for applications in autonomous navigation, robotics, and industrial metrology.

physics.optics↗

SPT-3G D1: Compton-$y$ maps using data from the SPT-3G and Planck surveys

We present thermal Sunyaev-Zel'dovich (tSZ) Compton-$y$ parameter maps constructed from two years (2019-2020) of observations with the South Pole Telescope (SPT) third-generation camera, SPT-3G, combined with data from the Planck satellite. Using a linear combination (LC) pipeline, we obtain a suite of reconstructions that explore different trade-offs between statistical sensitivity and suppression of astrophysical contaminants, including minimum-variance, CMB-deprojected, and CIB-deprojected $y$-maps. We validate these maps through different statistical techniques such as auto- and cross-power spectra with large-scale structure tracers as well as stacking on cluster locations. These tests are used to understand the balance between noise and astrophysical foreground residuals (such as the CIB) in combination with the recovery of the tSZ signal for different maps. For example, results from stacking at the location of clusters confirm the robustness of the recovered tSZ signal over the $\sim 1500\: {\rm deg}^2$ SPT-3G survey field used in this analysis. The high-resolution and low-noise maps produced here provide an important cosmological tool for future studies, including measurements of the Compton-$y$ map power spectrum, cross-correlations with other tracers of the large-scale structure, detailed modeling of cluster pressure profiles, and study of the thermodynamic state of the baryons in the Universe.

astro-ph.CO↗

Measurement of single charged pion production in charged-current $ν_μ$-Ar interactions with the MicroBooNE detector

We present flux-averaged charged-current $ν_μ$ cross-section measurements on argon for final states containing exactly one $π^\pm$ and no other hadrons except nucleons. The analysis uses data from the MicroBooNE experiment in the Booster Neutrino Beam, corresponding to $1.11 \times 10^{21}$ protons on target. Total and single-differential cross-section measurements are provided within a phase space restricted to muon momenta above 150 MeV, pion momenta above 100 MeV, and muon-pion opening angles smaller than 2.65 rad. Differential cross sections are reported with respect to the scattering angles of the muon and pion relative to the beam direction, their momenta, and their combined opening angle. The differential cross section with respect to muon momentum is based on a subset of selected events with the muon track fully contained in the detector, whereas the cross section with respect to pion momentum is based on a subset of selected events rich in pions that have not hadronically scattered on the argon before coming to rest. The latter has not been measured on argon before. The total cross section is measured as $(3.75~\pm~0.07~\textrm{(stat.)}~\pm~0.80~\textrm{(syst.)}) \times 10^{-38} \, \text{cm}^2/\text{Ar}$ at a mean energy of approximately 0.8 GeV. Comparisons of the measured cross sections with predictions from multiple neutrino-nucleus interaction generators show good overall agreement, except at very forward muon angles.

hep-ex↗

Deterministic Control of Extreme Events in a semiconductor VCSEL via Polarization-Engineered Optical Feedback

Extreme events, or rogue waves, are high-amplitude, rare occurrences that emerge across diverse physical systems and often defy conventional statistical predictions. While optical systems provide a controlled setting for studying these phenomena, achieving deterministic control over their generation remains challenging. Here, we demonstrate a novel approach to induce and precisely modulate extreme events in a semiconductor VCSEL using polarization-controlled optical feedback. By integrating a $λ$/2-waveplate into a polarization-selective external cavity, we regulate the nonlinear interaction between TE and TM modes. This setup triggers high-intensity, heavy-tailed fluctuations in the TM mode, exhibiting clear signatures of extreme events. We show that these events arise from deterministic energy exchange between modes, as evidenced by strong bipolar correlations and long-range temporal memory. The waveplate angle serves as an effective external parameter, enabling non-monotonic tuning of the event rate, intensity, and temporal clustering. Our study establish a platform for exploring extreme events in dissipative systems, with implications for nonlinear photonics and optical technologies.

physics.optics↗

A sudden dramatic change and recovery of magneto-environment of a repeating fast radio burst

Fast radio bursts (FRBs) are millisecond-duration radio bursts with unidentified extra-galactic origin. Some FRBs exhibit mild magneto-ionic environmental variations, possibly attributed to plasma turbulence or binary configuration. We report an abrupt magneto-ionic variation of FRB 20220529, a repeating FRB from a disk galaxy at redshift $0.1839 \pm 0.0001$. Initially, the Faraday rotation measure (RM) had a median of $17~{\rm rad~m^{-2}}$ and a scatter of $101~{\rm rad~m^{-2}}$ over 17 months. In December 2023, it jumped to $1977 \pm 84~{\rm rad~m^{-2}}$, and returned to typical values within two weeks. This drastic RM variation suggests that a dense magnetized clump enters and exits the line of sight in week timescales. One plausible scenario invokes a coronal mass ejection from a companion star, while other scenarios invoking extreme turbulence or binary orbital motion are also possible.

astro-ph.HE↗

The ALPINE-CRISTAL-JWST Survey: JWST/IFU Optical Observations for 18 Main-Sequence Galaxies at z=4-6

To fully characterize the formation and evolution of galaxies, we need to observe their stars, gas, and dust on resolved spatial scales. We present the ALPINE-CRISTAL-JWST survey, which combines kpc-resolved imaging and spectroscopy from HST, JWST, and ALMA for 18 representative main-sequence galaxies at z=4-6 and log(M/$M_\odot$) > 9.5 to study their star formation, chemical properties, and extended gas reservoirs. The co-spatial measurements resolving the ionized gas, molecular gas, stars, and dust on 1-2 kpc scales make this a unique benchmark sample for the study of galaxy formation and evolution at $z\sim5$, connecting the Epoch of Reionization with the cosmic noon. In this paper, we outline the survey goals and sample selection, and present a summary of the available data for the 18 galaxies. In addition, we measure spatially integrated quantities (such as global gas metallicity), test different star formation rate indicators, and quantify the presence of H$α$ halos. Our targeted galaxies are relatively metal rich (10-70% solar), complementary to JWST samples at lower stellar mass, and there is broad agreement between different star formation indicators. One galaxy has the signature of an active galactic nuclei (AGN) based on its emission line ratios. Six show broad H$α$~emission suggesting type 1 AGN candidates. We conclude with an outlook on the exciting science that will be pursued with this unique sample in forthcoming papers.

astro-ph.GA↗

Electric fields induced spin and/or valley polarization in Weiss oscillations of monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$

Monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$ exhibits spin- and valley-dependent massive tilted Dirac cones with two velocity correction terms in low-energy effective Hamiltonian. We theoretically investigate the longitudinal diffusive magneto-conductivity of monolayer 1{\it T}$^{\prime}$-$\mathrm{MoS}_{2}$ by using the linear response theory. It is shown that the Weiss oscillations are polarized in spin and valley degrees of freedom, under uniform electric fields and a weak one-dimensional spatially-periodic electrostatic potential modulation. The spin polarization, the valley polarization and the spin-valley polarization can be switched by flipping the external electric fields. The polarization is found not only in the amplitudes but also in the periods of the Weiss oscillations. It is found that the period polarization in Weiss oscillations originates from the polarized effective Fermi energies or the polarized Landau level spacing scales. In Weiss oscillations, polarization in amplitude does not imply the presence of polarization in period, whereas polarization in period is accompanied by polarization in amplitude. The superposition of polarization in amplitude and polarization in period enables the appearance of considerable polarization in Weiss oscillations under relatively weak external electric fields.

cond-mat.mes-hall↗

Search for Light Sterile Neutrinos With Two Neutrino Beams at MicroBooNE

The existence of three distinct neutrino flavours, $ν_{e}$, $ν_μ$, and $ν_τ$, is a central tenet of the Standard Model of particle physics. Quantum-mechanical interference can allow a neutrino of one initial flavour to be detected some time later as a different flavour, a process called neutrino oscillation. Several anomalous observations inconsistent with this three-flavour picture have motivated the hypothesis that an additional neutrino state exists which does not interact directly with matter, termed a "sterile" neutrino, $ν_s$. This includes anomalous observations from the LSND and MiniBooNE experiments, consistent with $ν_μ\rightarrowν_{e}$ transitions at a distance inconsistent with the three-neutrino picture. Here, we use data obtained from the MicroBooNE liquid-argon time projection chamber in two accelerator neutrino beams to exclude the single light sterile neutrino interpretation of the LSND and MiniBooNE anomalies at the 95\% confidence level (CL). Additionally, we rule out a significant portion of the parameter space that could explain the gallium anomaly. This is the first measurement to use two accelerator neutrino beams to break a degeneracy between $ν_{e}$ appearance and disappearance that would otherwise weaken the sensitivity to the sterile neutrino hypothesis. We find no evidence for either $ν_μ\rightarrowν_{e}$ flavour transitions or $ν_{e}$ disappearance that would indicate non-standard flavour oscillations. Our results show that previous anomalous observations consistent with $ν_μ\rightarrowν_{e}$ transitions cannot be explained by introducing a single sterile neutrino state.

hep-ex↗

Lattice Boltzmann models for the hydrodynamic equations in multiphase flow with high density ratio

Multiphase flows with high density ratios, such as water and air flows, have recently been simulated using the lattice Boltzmann (LB) method. This approach corresponds to solving the phase field equations, such as the Cahn-Hilliard and Allen-Cahn equations, and the hydrodynamic equations, typically the Navier-Stokes and pressure equations for pseudo-incompressible fluids. Due to the high density ratio, the higher-order numerical truncation errors associated with spatial density gradients can become significant. These errors can lead to problems such as inaccuracies in shear stress, violations of Galilean invariance, and undesirable dependencies on absolute pressure for the pseudo-incompressible solutions. To overcome such problems, the moments of the distribution function and the equilibrium state must be carefully designed while ensuring robustness. In this work, we propose a new scheme based on the lattice kinetic scheme (LKS), which directly solves the velocity and pressure fields in the similar discrete space as the LB method. When mapping the LKS-based models to the LB models, the original LKS models are simplified for computational efficiency and the filter collision operator is implemented. Benchmark test cases confirm that the proposed scheme effectively addresses these issues, achieving high accuracy and robustness while eliminating the iterative steps typically required in the LKS. One of the most significant improvements is the accuracy of the airflow field induced by water motion, likely due to improved momentum transfer across the interface.

physics.flu-dyn↗

Measurement of three-dimensional inclusive muon-neutrino charged-current cross sections on argon with the MicroBooNE detector

We report the measurement of the differential cross section $d^{2}σ(E_ν)/ d\cos(θ_μ) dP_μ$ for inclusive muon-neutrino charged-current scattering on argon. This measurement utilizes data from 6.4$\times10^{20}$ protons on target of exposure collected using the MicroBooNE liquid argon time projection chamber located along the Fermilab Booster Neutrino Beam with a mean neutrino energy of approximately 0.8~GeV. The mapping from reconstructed kinematics to truth quantities, particularly from reconstructed to true neutrino energy, is validated within uncertainties by comparing the distribution of reconstructed hadronic energy in data to that of the model prediction in different muon scattering angle bins after applying a conditional constraint from the muon momentum distribution in data. The success of this validation gives confidence that the missing energy in the MicroBooNE detector is well-modeled within uncertainties in simulation, enabling the unfolding to a three-dimensional measurement over muon momentum, muon scattering angle, and neutrino energy. The unfolded measurement covers an extensive phase space, providing a wealth of information useful for future liquid argon time projection chamber experiments measuring neutrino oscillations. Comparisons against a number of commonly used model predictions are included and their performance in different parts of the available phase-space is discussed.

hep-ex↗

Enhanced search for neutral current $Δ$ radiative single-photon production in MicroBooNE

We report results from an updated search for neutral current (NC) resonant $Δ$(1232) baryon production and subsequent $Δ$ radiative decay (NC $Δ\rightarrow N γ$). We consider events with and without final state protons; events with a proton can be compared with the kinematics of a $Δ(1232)$ baryon decay, while events without a visible proton represent a more generic phase space. In order to maximize sensitivity to each topology, we simultaneously make use of two different reconstruction paradigms, Pandora and Wire-Cell, which have complementary strengths, and select mostly orthogonal sets of events. Considering an overall scaling of the NC $Δ\rightarrow N γ$ rate as an explanation of the MiniBooNE anomaly, our data exclude this hypothesis at 94.4% CL. When we decouple the expected correlations between NC $Δ\rightarrow N γ$ events with and without final state protons, and allow independent scaling of both types of events, our data exclude explanations in which excess events have associated protons, and do not exclude explanations in which excess events have no associated protons.

hep-ex↗

First Measurement of Charged Current Muon Neutrino-Induced $K^+$ Production on Argon using the MicroBooNE Detector

The MicroBooNE experiment is an 85 tonne active mass liquid argon time projection chamber neutrino detector exposed to the on-axis Booster Neutrino Beam (BNB) at Fermilab. One of MicroBooNE's physics goals is the precise measurement of neutrino interactions on argon in the 1 GeV energy regime. Building on the capabilities of the MicroBooNE detector, this analysis identifies $K^{+}$ mesons, a key signature for the study of strange particle production in neutrino interactions. This measurement is furthermore valuable for background estimation for future nucleon decay searches and for improved reconstruction and particle identification capabilities in experiments such as the Deep Underground Neutrino Experiment (DUNE). In this letter, we present the first-ever measurement of a flux-integrated cross section for charged-current muon neutrino induced $K^{+}$ production on argon nuclei, determined to be 7.93 $\pm$ 3.22 (stat.) $\pm$ 2.83 (syst.) $\times~10^{-42}\;$ cm$^2$/nucleon based on an analysis of 6.88$\times10^{20}$ protons on target. This result was found to be consistent with model predictions from different neutrino event generators within the reported uncertainties.

hep-ex↗

Policy-Guided MCTS for near Maximum-Likelihood Decoding of Short Codes

In this paper, we propose a policy-guided Monte Carlo Tree Search (MCTS) decoder that achieves near maximum-likelihood decoding (MLD) performance for short block codes. The MCTS decoder searches for test error patterns (TEPs) in the received information bits and obtains codeword candidates through re-encoding. The TEP search is executed on a tree structure, guided by a neural network policy trained via MCTS-based learning. The trained policy guides the decoder to find the correct TEPs with minimal steps from the root node (all-zero TEP). The decoder outputs the codeword with maximum likelihood when the early stopping criterion is satisfied. The proposed method requires no Gaussian elimination (GE) compared to ordered statistics decoding (OSD) and can reduce search complexity by 95\% compared to non-GE OSD. It achieves lower decoding latency than both OSD and non-GE OSD at high SNRs.

cs.IT↗