arXiv subjects

Jonghee Yoo

Publications and source records attributed to Jonghee Yoo.

12 recordsLinked to original sources

arXiv2026

Characterization of the 20-inch Photomultiplier Tubes for RENE Detector

To address the Reactor Antineutrino Anomaly (RAA) observed in neutrino experiments, the Reactor Experiment for Neutrino and Exotics (RENE) has been initiated using a liquid scintillation detector. In this study, we investigate the characteristics of two 20-inch Hamamatsu R12860 photomultiplier tubes (PMTs) intended for installation in the RENE detector. The charge and timing responses of the PMTs were evaluated at both the nominal and target gains expected during actual operation. In particular, gain non-uniformity arising from the large-diameter photocathode with a box-and-line type dynode structure was examined, and the maximum gain variation was measured. The occurrence rate, timing, and charge distributions of late pulses and afterpulses were also investigated to characterize the specific response features of the R12860 PMT. The results reported in this study will aid in the interpretation of signals from the RENE detector and serve as a reference for estimating potential systematic uncertainties in RENE data. Furthermore, these findings are expected to provide valuable information for other experiments employing the same type of PMTs.

physics.ins-det↗

arXiv2025

RENE experiment for the sterile neutrino search using reactor neutrinos

This paper summarizes the details of the Reactor Experiment for Neutrinos and Exotics (RENE) experiment. It covers the detector construction, Monte Carlo (MC) simulation study, and physics expectations. The primary goal of the RENE project is to investigate the sterile neutrino oscillation at $\Delta{m}^{2}_{41}\sim 2\,{\rm{eV}^{2}}$. which overlap with the allowed region predicted by the Reactor Antineutrino Anomaly (RAA). On the other hand, the STEREO and PROSPECT experiments have excluded certain regions of the parameter space with 95 \% confidence level (C.L.), while the joint study conducted by RENO and NEOS suggests possible indications of sterile neutrinos at $\Delta{m}^{2}_{41}\sim2.4\,{\rm{eV}^{2}}$ and $\sim{1.7}{\,\rm{eV}^{2}}$ with sin$^{2}\theta_{41} < 0.01$. Accordingly, a more meticulous investigation of these remaining regions continues to be a scientifically valuable endeavor. This paper reports the technical details of the detector and physics objectives.

hep-ex↗

arXiv2023

Extended Axion Dark Matter Search Using the CAPP18T Haloscope

We report an extended search for the axion dark matter using the CAPP18T haloscope. The CAPP18T experiment adopts innovative technologies of a high-temperature superconducting magnet and a Josephson parametric converter. The CAPP18T detector was reconstructed after an unexpected incident of the high-temperature superconducting magnet quenching. The system reconstruction includes rebuilding the magnet, improving the impedance matching in the microwave chain, and mechanically readjusting the tuning rod to the cavity for improved thermal contact. The total system noise temperature is $\sim$0.6\,K. The coupling between the cavity and the strong antenna is maintained at $β\simeq 2$ to enhance the axion search scanning speed. The scan frequency range is from 4.8077 to 4.8181 GHz. No significant indication of the axion dark matter signature is observed. The results set the best upper bound of the axion-photon-photon coupling ($g_{aγγ}$) in the mass ranges of 19.883 to 19.926\,$μ$eV at $\sim$0.7$\times|g_{aγγ}^{\text{KSVZ}}|$ or $\sim$1.9$\times|g_{aγγ}^{\text{DFSZ}}|$ with 90\,\% confidence level. The results demonstrate that a reliable search of the high-mass dark matter axions can be achieved beyond the benchmark models using the technology adopted in CAPP18T.

hep-ex↗

arXiv2022

Axion Haloscope Using an 18 T High Temperature Superconducting Magnet

We report details on the axion dark matter search experiment that uses the innovative technologies of a High-Temperature Superconducting (HTS) magnet and a Josephson Parametric Converter (JPC). An 18 T HTS solenoid magnet is developed for this experiment. The JPC is used as the first stage amplifier to achieve a near quantum-limited low-noise condition. The first dark matter axion search was performed with the 18 T axion haloscope. The scan frequency range is from 4.7789 GHz to 4.8094 GHz (30.5 MHz range). No significant signal consistent with Galactic dark matter axion is observed. Our results set the best limit of the axion-photon-photon coupling ($g_{aγγ}$) in the axion mass range of 19.764 to 19.890 $μ$eV. Using the Bayesian method, the upper bounds of $g_{aγγ}$ are set at 0.98$\times|g_{aγγ}^{\text{KSVZ}}|$ (1.11$\times|g_{aγγ}^{\text{KSVZ}}|$) in the mass ranges of 19.764 to 19.771 $μ$eV (19.863 to 19.890 $μ$eV), and at 1.76 $\times|g_{aγγ}^{\text{KSVZ}}|$ in the mass ranges of 19.772 to 19.863 $μ$eV with 90\% confidence level, respectively. We report design, construction, operation, and data analysis of the 18 T axion haloscope experiment.

hep-ex↗

arXiv2022

Searching for Invisible Axion Dark Matter with an 18T Magnet Haloscope

We report the first search results for axion dark matter using an 18\,T high-temperature superconducting magnet haloscope. The scan frequency ranges from 4.7789 to 4.8094\,GHz. No significant signal consistent with the Galactic halo dark matter axion is observed. The results set the best upper bound of axion-photon-photon coupling ($g_{aγγ}$) in the mass ranges of 19.764 to 19.771\,$μ$eV (19.863 to 19.890\,$μ$eV) at 1.5$\times|g_{aγγ}^{\text{KSVZ}}|$ (1.7$\times|g_{aγγ}^{\text{KSVZ}}|$), and 19.772 to 19.863\,$μ$eV at 2.7 $\times|g_{aγγ}^{\text{KSVZ}}|$ with 90\% confidence level, respectively. This remarkable sensitivity in the high mass region of dark matter axion is achieved by using the strongest magnetic field among the existing haloscope experiments and realizing a low-noise amplification of microwave signals using a Josephson parametric converter.

hep-ex↗

arXiv2017

Magnetoresistance in copper at high frequency and high magnetic fields

In halo dark matter axion search experiments, cylindrical microwave cavities are typically employed to detect signals from the axion-photon conversion. To enhance the conversion power and reduce the noise level, cavities are placed in strong solenoid magnetic fields at sufficiently low temperatures. Exploring high mass regions in cavity-based axion search experiments requires high frequency microwave cavities and thus understanding cavity properties at high frequencies in extreme conditions is deemed necessary. We present a study of the magnetoresistance of copper using a cavity with a resonant frequency of 12.9 GHz at the liquid helium temperature in magnetic fields up to 15 T utilizing a second generation high temperature superconducting magnet. The observations are interpreted to be consistent with the anomalous skin effect and size effect. This is the first measurement of magnetoresistance at a high frequency (> 10 GHz) in high magnetic fields (> 10 T).

physics.ins-det↗

arXiv2015

Dark Matter Directionality Revisited with a High Pressure Xenon Gas Detector

An observation of the anisotropy of dark matter interactions in a direction-sensitive detector would provide decisive evidence for the discovery of galactic dark matter. Directional information would also provide a crucial input to understanding its distribution in the local Universe. Most of the existing directional dark matter detectors utilize particle tracking methods in a low-pressure gas time projection chamber. These low pressure detectors require excessively large volumes in order to be competitive in the search for physics beyond the current limit. In order to avoid these volume limitations, we consider a novel proposal, which exploits a columnar recombination effect in a high-pressure gas time projection chamber. The ratio of scintillation to ionization signals observed in the detector carries the angular information of the particle interactions. In this paper, we investigate the sensitivity of a future directional detector focused on the proposed high-pressure Xenon gas time projection chamber. We study the prospect of detecting an anisotropy in the dark matter velocity distribution. We find that tens of events are needed to exclude an isotropic distribution of dark matter interactions at 95% confidence level in the most optimistic case with head-to-tail information. However, one needs at least 10-20 times more events without head-to-tail information for light dark matter below 50 GeV. For an intermediate mass range, we find it challenging to observe an anisotropy of the dark matter distribution. Our results also show that the directional information significantly improves precision measurements of dark matter mass and the elastic scattering cross section for a heavy dark matter.

hep-ph↗

arXiv2013

Dark Matter in the Coming Decade: Complementary Paths to Discovery and Beyond

In this Report we discuss the four complementary searches for the identity of dark matter: direct detection experiments that look for dark matter interacting in the lab, indirect detection experiments that connect lab signals to dark matter in our own and other galaxies, collider experiments that elucidate the particle properties of dark matter, and astrophysical probes sensitive to non-gravitational interactions of dark matter. The complementarity among the different dark matter searches is discussed qualitatively and illustrated quantitatively in several theoretical scenarios. Our primary conclusion is that the diversity of possible dark matter candidates requires a balanced program based on all four of those approaches.

hep-ph↗

arXiv2013

Kaluza-Klein Dark Matter: Direct Detection vis-a-vis LHC (2013 update)

We present updated results on the complementarity between high-energy colliders and dark matter direct detection experiments in the context of Universal Extra Dimensions (UED). In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UED provide a natural framework to study such mass degeneracies. We discuss the detection prospects for the KK photon $γ_1$ and the KK $Z$-boson $Z_1$, combining the expected LHC reach with cosmological constraints from WMAP/Planck, and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, neither colliders, nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions, and the combination of the two types of constraints can be quite powerful.

hep-ph↗

arXiv2008

Kaluza-Klein Dark Matter: Direct Detection vis-a-vis LHC (IDM 2008 proceeding)

We explore the phenomenology of Kaluza-Klein (KK) dark matter in very general models with universal extra dimensions (UEDs), emphasizing the complementarity between high-energy colliders and dark matter direct detection experiments. In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UEDs provide a natural framework for such mass degeneracies. We consider both 5-dimensional and 6-dimensional non-minimal UED models, and discuss the detection prospects for various KK dark matter candidates: the KK photon γ_1 (5D) the KK Z-boson Z_1 (5D) and the spinless KK photon γ_H (6D). We combine collider limits such as electroweak precision data and expected LHC reach, with cosmological constraints from WMAP and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, we show that neither colliders, nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions and the combination of the two types of constraints can be quite powerful. For example, in the case of γ_1 in 5D UEDs the relevant parameter space will be almost completely covered by the combined LHC and direct detection sensitivities expected in the near future.

hep-ph↗

arXiv2008

Results from the CDMS 5-Tower Operation

Astrophysical observations strongly suggest that non-luminous, nonbaryonic components, so called "Dark Matter", may constitute most of the matter in the Universe. The Cryogenic Dark Matter Search (CDMS) experiment is designed to detect Dark Matter interaction events through nuclear recoils from elastic scattering. The detector is capable of reading out both phonon and ionization energy of an interaction in Ge or Si crystals. We present results from the CDMS five-tower detector arrays. The data were collected in the period between October 2006 and July 2007 (with an effective exposure of 121.3 kg-days). No WIMP signal was observed. The results, when combined with previous CDMS Soudan data, set a 90% confidence level upper bound on the WIMP-nucleon cross section of $4.6\times 10^{-44}$ cm$^2$ at 60 Gev/c$^2$ WIMP mass.

hep-ex↗

arXiv2008

Kaluza-Klein Dark Matter: Direct Detection vis-a-vis LHC

We explore the phenomenology of Kaluza-Klein (KK) dark matter in very general models with universal extra dimensions (UEDs), emphasizing the complementarity between high-energy colliders and dark matter direct detection experiments. In models with relatively small mass splittings between the dark matter candidate and the rest of the (colored) spectrum, the collider sensitivity is diminished, but direct detection rates are enhanced. UEDs provide a natural framework for such mass degeneracies. We consider both 5-dimensional and 6-dimensional non-minimal UED models, and discuss the detection prospects for various KK dark matter candidates: the KK photon $γ_1$, the KK $Z$-boson $Z_1$, the KK Higgs boson $H_1$ and the spinless KK photon $γ_H$. We combine collider limits such as electroweak precision data and expected LHC reach, with cosmological constraints from WMAP, and the sensitivity of current or planned direct detection experiments. Allowing for general mass splittings, we show that neither colliders, nor direct detection experiments by themselves can explore all of the relevant KK dark matter parameter space. Nevertheless, they probe different parameter space regions, and the combination of the two types of constraints can be quite powerful. For example, in the case of $γ_1$ in 5D UEDs the relevant parameter space will be almost completely covered by the combined LHC and direct detection sensitivities expected in the near future.

hep-ph↗