Electron-phonon scatterings in solid-state systems are pivotal processes in determining many key physical quantities such as charge carrier mobilities and thermal conductivities. Here, we report on the direct probing of phonon mode specific electron-phonon scatterings in layered semiconducting transition metal dichalcogenides WSe2, MoSe2, WS2, and MoS2 through inelastic electron tunneling spectroscopy measurements, quantum transport simulations, and density functional calculation. We experimentally and theoretically characterize momentum-conserving single- and two-phonon electron-phonon scatterings involving up to as many as eight individual phonon modes in mono- and bilayer films, among which transverse, longitudinal acoustic and optical, and flexural optical phonons play significant roles in quantum charge flows. Moreover, we observe that two-phonon inelastic electron tunneling processes, which are confirmed to be generic in all four semiconducting layers, are governed by layer-number dependent symmetry, quantum interference, and geometric Berry phase.

Duk Hyun Lee Sang-Jun Choi Hakseong Kim Yong-Sung Kim Suyong Jung

The D0 collaboration has performed a study of spin correlation in tt-bar production for the process tt-bar to bb-bar W^+W^-, where the W bosons decay to e-nu or mu-nu. A sample of six events was collected during an exposure of the D0 detector to an integrated luminosity of approximately 125 pb^-1 of sqrt{s}=1.8 TeV pp-bar collisions. The standard model (SM) predicts that the short lifetime of the top quark ensures the transmission of any spin information at production to the tt-bar decay products. The degree of spin correlation is characterized by a correlation coefficient k. We find that k>-0.25 at the 68% confidence level, in agreement with the SM prediction of k=0.88.

D0 Collaboration B. Abbott

We address the problem of a search at the LHC for a neutralino whose mass is around 10 GeV, i.e. in the range of interest for present data of direct search for dark matter particles in the galactic halo. This light neutralino is here implemented in an effective Minimal Supersymmetric extension of the Standard Model at the electroweak scale without requirement of a gaugino-mass unification at a grand unification scale. Within this model we select a representative benchmark and determine its prospects of reconstructing the main features of the model at different stages of the LHC runs.

Suyong Choi S. Scopel N. Fornengo A. Bottino

We present a new observable, $\Delta \phi$, an azimuthal angle difference between $t$ and $\bar{t}$ quarks in $t\bar{t}$ pair production, at hadron colliders as an interesting probe of the radiative quantum chromodynamics process as well as a high-order correction in the high-mass regime. This variable also enables good discrimination on some new physics models that may explain the forward-backward charge asymmetry of $t\bar{t}$ production measured at the Tevatron. With a reliable estimation of the dataset obtained up to 2011 at the Tevatron and Large Hadron Collider, we present an opportunity for testing the standard model as well as searching new physics models with the $\Delta \phi$ observable.

Suyong Choi Hyun Su Lee

Neural network-based algorithms provide a promising approach to jet classification problems, such as boosted top jet tagging. To date, NN-based top taggers demonstrated excellent performance in Monte Carlo studies. In this paper, we construct a top-jet tagger based on a Convolutional Neural Network (CNN), and apply it to parton-level boosted top samples, with and without an additional gluon in the final state. We show that the jet observable defined by the CNN obeys the canonical definition of infrared safety: it is unaffected by the presence of the extra gluon, as long as it is soft or collinear with one of the quarks. Our results indicate that the CNN tagger is robust with respect to possible mis-modeling of soft and collinear final-state radiation by Monte Carlo generators.

Suyong Choi Seung J. Lee Maxim Perelstein

We report a measurement of the fraction of top quark pair events produced via gluon-gluon fusion in $p\bar{p}$ collisions at $\sqrt{s} = 1.96 ~\rm TeV$ in lepton+jets final states using the full RunII data set corresponding to $9.7 ~\rm fb^{-1}$ of integrated luminosity collected by the D\O\ experiment. We utilize a boosted decision tree to distinguish top quark pair events produced by $q\bar{q}$ annihilation and $gg$ fusion. We perform a template fit to extract the $t\bar{t}$ production fraction via $gg$ fusion and find $f_{gg} = 0.096 \pm 0.039 ~(\rm stat.) ~^{+0.077}_{-0.062} ~(\rm syst.)$.

Sungwoong Cho Suyong Choi Sehwook Lee JaeHoon Lim SungWoo Youn

We propose a new experiment sensitive to the detection of millicharged particles produced at the $30$ GeV proton fixed-target collisions at J-PARC. The potential site for the experiment is B2 of the Neutrino Monitor building, $280$ m away from the target. With $\textrm{N}_\textrm{POT}=10^{22}$, the experiment can provide sensitivity to particles with electric charge $3\times10^{-4}\,e$ for mass less than $0.2$ $\textrm{GeV}/\textrm{c}^2$ and $1.5\times10^{-3}\,e$ for mass less than $1.6$ $\textrm{GeV}/\textrm{c}^2$. This brings a substantial extension to the current constraints on the charge and the mass of such particles.

Suyong Choi Jeong Hwa Kim Eunil Won Jae Hyeok Yoo Matthew Citron David Stuart Christopher S. Hill Andy Haas Jihad Sahili Haitham Zaraket A. De Roeck Martin Gastal

We present a novel-view rendering algorithm, Mode-GS, for ground-robot trajectory datasets. Our approach is based on using anchored Gaussian splats, which are designed to overcome the limitations of existing 3D Gaussian splatting algorithms. Prior neural rendering methods suffer from severe splat drift due to scene complexity and insufficient multi-view observation, and can fail to fix splats on the true geometry in ground-robot datasets. Our method integrates pixel-aligned anchors from monocular depths and generates Gaussian splats around these anchors using residual-form Gaussian decoders. To address the inherent scale ambiguity of monocular depth, we parameterize anchors with per-view depth-scales and employ scale-consistent depth loss for online scale calibration. Our method results in improved rendering performance, based on PSNR, SSIM, and LPIPS metrics, in ground scenes with free trajectory patterns, and achieves state-of-the-art rendering performance on the R3LIVE odometry dataset and the Tanks and Temples dataset.

Yonghan Lee Jaehoon Choi Dongki Jung Jaeseong Yun Soohyun Ryu Dinesh Manocha Suyong Yeon

We introduce the first learning-based dense matching algorithm, termed Equirectangular Projection-Oriented Dense Kernelized Feature Matching (EDM), specifically designed for omnidirectional images. Equirectangular projection (ERP) images, with their large fields of view, are particularly suited for dense matching techniques that aim to establish comprehensive correspondences across images. However, ERP images are subject to significant distortions, which we address by leveraging the spherical camera model and geodesic flow refinement in the dense matching method. To further mitigate these distortions, we propose spherical positional embeddings based on 3D Cartesian coordinates of the feature grid. Additionally, our method incorporates bidirectional transformations between spherical and Cartesian coordinate systems during refinement, utilizing a unit sphere to improve matching performance. We demonstrate that our proposed method achieves notable performance enhancements, with improvements of +26.72 and +42.62 in AUC@5{\deg} on the Matterport3D and Stanford2D3D datasets.

Dongki Jung Jaehoon Choi Yonghan Lee Somi Jeong Taejae Lee Dinesh Manocha Suyong Yeon

We present a detailed description of the detector design for the SUB-Millicharge ExperimenT (SUBMET), developed to search for millicharged particles. The experiment probes a largely unexplored region of the charge-mass parameter space, focusing on particles with mass $m_\chi < 1.6~\textrm{GeV}/c^2$ and electric charge $Q < 10^{-3}e$. The detector has been optimized to achieve high sensitivity to interactions of such particles while maintaining effective discrimination against background events. We provide a comprehensive overview of the key detector components, including scintillation modules, photomultiplier tubes, and the mechanical support structure.

Claudio Campagnari Sungwoong Cho Suyong Choi Seokju Chung Matthew Citron Albert De Roeck Martin Gastal Seungkyu Ha Andy Haas Christopher Scott Hill Byeong Jin Hong Haeyun Hwang Insung Hwang Hoyong Jeong Hyunki Moon Jayashri Padmanaban Ryan Schmitz Changhyun Seo David Stuart Eunil Won Jae Hyeok Yoo Jinseok Yoo Ayman Youssef Ahmad Zaraket Haitham Zaraket