Jaehyeok Yoo

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 $1.6$ $\textr

A bstract We study the electroweak dilepton production with two forward jets at the LHC, aiming to measure the anomalous triple gauge couplings in the Effective Field Theory (EFT) approach. This process exhibits a distinctive feature, namely, the interference between Standard Model (SM) and beyond the SM is resurrected in the inclusive cross section of the full amplitude, including two forward jets. As a concrete illustration, we perform the detailed analytic and numerical study of the interfere

Abstract 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 $m_\chi < 1.6\,\rm {GeV}/c^2$ 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 agains

Recently, a search for milli-charged particles produced at the LHC has been proposed. The experiment, named milliQan, is expected to obtain sensitivity to charges of $10^{-1} - 10^{-3}e$ for masses in the 0.1 - 100 GeV range. The detector is composed of 3 stacks of 80 cm long plastic scintillator arrays read out by PMTs. It will be installed in an existing tunnel 33 m from the CMS interaction point at the LHC, with 17 m of rock shielding to suppress beam backgrounds. In the fall of 2017 a 1% sca

SUB-Millicharge ExperimenT (SUBMET) searches for millicharged particles $\chi$ that can be produced from the 30 GeV proton fixed-target collisions at J-PARC. It targets low-mass and low-charge region that has not been probed by the existing searches, more specifically, $m_\chi<1. 6$ GeV and $\epsilon = Q/e < 10^{-3}$. The detector is composed of two stacks of long plastic scintillators and is installed on the bottom floor of the Neutrino Monitor building. It was assembled and tested in Korea, be

The {$\bfνEYE$} (``new eye'', Neutrino Experiment at YEmilab, \href{https://sites.google.com/korea.ac.kr/the-nueye-telescope} {\tt nuEYE.korea.ac.kr}) neutrino project leverages the existing large pit at Yemilab located in South Korea, to reveal the existence of sterile neutrino, the up-turn of the neutrinos from the Sun, and the first minimum of the neutrino oscillation over distances on the order of tens of kilometers for the first time. This initiative is expected to facilitate a wide range o

Abstract The SUB-Millicharge ExperimenT (SUBMET) investigates an unexplored parameter space of millicharged particles with mass $m_\chi &amp;lt;$ 1.6 GeV/c$^2$ and charge $Q_\chi &amp;lt; 10^{-3}e$. The detector consists of an Eljen-200 plastic scintillator coupled to a Hamamatsu Photonics R7725 photomultiplier tube (PMT). PMT afterpulses, delayed pulses produced after an energetic pulse, have been observed in the SUBMET readout system, especially following primary pulses with a large area. We p

Low-Gain Avalanche Diode (LGAD) sensors, offering timing resolutions of the order of tens of picoseconds, are being widely adopted in particle physics experiments and related applications. As these applications scale to large numbers of sensors with varying pixel geometries, conventional manual characterization techniques become inadequate for large-scale quality control. We present a modular probe card system for automated electrical characterization of pixelated LGAD sensors, consisting of a p

International audience

In this thesis, we report the result on the search for the Standard Model(SM) Higgs boson decaying to a pair of W in the full leptonic final state using data collected by CMS detector at LHC at 7 and 8 TeV. The integrated luminosity is 4.9 /fb⁻¹ and 19.5 /fb⁻¹ at 7 and 8 TeV, respectively. The SM Higgs hypothesis is excluded at CLs=95 % in mH = 128 - 600 GeV. An excess of data is ob- served around mH = 125 GeV which corresponds to significance of 4.0[sigma] on the background-only hypothesi

In this paper, we propose an experiment, LANSCE-mQ, aiming to detect fractionally charged and millicharged particles (mCP) using an 800 MeV proton beam fixed target at the Los Alamos Neutron Science Center (LANSCE) facility. This search can shed new light on numerous fundamental questions, including charge quantization, the predictions of string theories and grand unification theories, the gauge symmetry of the Standard Model, dark sector models, and the tests of cosmic reheating. We propose to