A5079973099- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- Particle Detector Development and Performance
- Dark Matter and Cosmic Phenomena
- High-Energy Particle Collisions Research
- Quasicrystal Structures and Properties
- Advanced Chemical Physics Studies
- Graphene research and applications
- Fullerene Chemistry and Applications
- X-ray Diffraction in Crystallography
- Superconducting Materials and Applications
- Computational Physics and Python Applications
- Surface and Thin Film Phenomena
- Particle Accelerators and Free-Electron Lasers
- Quantum Computing Algorithms and Architecture
- Neutrino Physics Research
- Crystal Structures and Properties
- Intermetallics and Advanced Alloy Properties
- Particle accelerators and beam dynamics
- Atomic and Subatomic Physics Research
- Boron and Carbon Nanomaterials Research
- Magnetic confinement fusion research
- Noncommutative and Quantum Gravity Theories
- Mineralogy and Gemology Studies
University of Michigan
2014-2021
Japan Proton Accelerator Research Complex
2020
High Energy Accelerator Research Organization
2020
Pennsylvania State University
2012-2015
A search for the rare decay K_{L}→π^{0}νν[over ¯] was performed. With data collected in 2015, corresponding to 2.2×10^{19} protons on target, a single event sensitivity of (1.30±0.01_{stat}±0.14_{syst})×10^{-9} achieved and no candidate events were observed. We set an upper limit 3.0×10^{-9} branching fraction at 90% confidence level (C.L.), which improved previous by almost order magnitude. An K_{L}→π^{0}X^{0} also as 2.4×10^{-9} C.L., where X^{0} is invisible boson with mass 135 MeV/c^{2}.
The KOTO collaboration has now carefully analyzed widely discussed preliminary data containing four signal events for a rare kaon decay---an excess suggesting physics beyond the Standard Model---and found that Model background are large enough to explain signal.
We have used scanning tunneling microscopy (STM), low-energy electron diffraction (LEED), and density functional theory (DFT) to elucidate the structure thermodynamics of (2$\sqrt{3}$ \ifmmode\times\else\texttimes\fi{} 2$\sqrt{3}$)$R$30\ifmmode^\circ\else\textdegree\fi{} phase C${}_{60}$ on Ag(111), which consists a mixture molecules in two different site/orientation states. The analysis identifies types as (1) sitting vacancy with hexagon face down (2) top site C-C bond down. flip between...
C${}_{60}$ monolayers grown on Ag(111) at room temperature form incommensurate lattices that convert into a commensurate (2$\sqrt{3}$ \ifmmode\times\else\texttimes\fi{} 2$\sqrt{3}$)R30\ifmmode^\circ\else\textdegree\fi{} phase upon annealing. The molecules in the have been observed to exist three different states Ag(111), namely bright, dim, and superbright (SB). All species are dynamical equilibrium 280 $T$ 440 K. bright dim were subject of an earlier low-energy electron diffraction study...
We searched for the $CP$-violating rare decay of neutral kaon, $K_{L} \to π^0 ν\overlineν$, in data from first 100 hours physics running 2013 J-PARC KOTO experiment. One candidate event was observed while $0.34\pm0.16$ background events were expected. set an upper limit $5.1\times10^{-8}$ branching fraction at 90\% confidence level (C.L.). An $3.7\times10^{-8}$ C.L. π^{0} X^{0}$decay also time, where $X^{0}$ is invisible particle with a mass 135 MeV/$c^{2}$.
The quantitative structure determination of adsorbed species on quasicrystal surfaces has so far appeared to present insurmountable problems. normal incidence standing x-ray wave field technique offers a simple solution, without extensive data sets or large computations. Its application quasicrystals raises several conceptual difficulties that are related the phase problem in diffraction. We demonstrate their solution for case Si atoms decagonal Co-rich modification Al-Co-Ni determine local...
The KOTO experiment at J-PARC, Japan, aims to observe the rare neutral kaon decay mode K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> → π <sup xmlns:xlink="http://www.w3.org/1999/xlink">0</sup> νν̅. After first experimental run in May 2013 a 24-kW beam power, data acquisition (DAQ) system was upgraded 2015 provide efficient and reliable collection higher intensities. Lossless compression analog-to-digital converter modules implemented...
We report the first search for $K_L \to \pi^0 \gamma$ decay, which is forbidden by Lorentz invariance, using data from 2016 to 2018 at J-PARC KOTO experiment. With a single event sensitivity of $(7.1\pm 0.3_{\rm stat.} \pm 1.6_{\rm syst.})\times 10^{-8}$, no candidate was observed in signal region. The upper limit on branching fraction set be $1.7\times 10^{-7}$ 90\% confidence level.
Quantitative adsorption structure determinations on quasicrystals are scarce because most techniques for measuring surface structures not well suited to the complex and infinite unit cells of quasicrystals. The normal incidence standing x-ray wave field technique presents a solution these problems it can be made inherently sensitive does involve extensive computational effort. We describe method applying this adsorbates quasicrystals, with specific application submonolayer Si atoms decagonal...
The KOTO experiment at J-PARC in Tokai, Ibaraki, Japan, aims to observe rare neutral kaon decay mode K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</sub> → π <sup xmlns:xlink="http://www.w3.org/1999/xlink">0</sup> νν. Followed by the first physics run May 2013 with 24 kW beam power, we upgraded data acquisition system 2015 accommodate efficient and reliable collection higher intensities. Lossless compression inside ADC modules was...
The goal of KOTO experiment at J-PARC is to discover and measure the rate rare decay K L → π 0 ν ν, for which Standard Model predicts a branching ratio (2.4 ± 0.4)×10 -11 .The
The KOTO data acquisition system (DAQ) collects detector PMT waveform signals and saves digitized events to permanent storage using frontend ADC modules, two levels of hardware triggers, a computing farm. DAQ ran stably in 2013 with 24 kW beam power. To maintain high livetime increasing power, we implemented lossless compression inside the modules developed new L3 upgraded was able above 80% 42 power during 2015 2016 runs. sustain for taking 50 above, an upgrade our trigger is proposed.
The KOTO experiment is a particle physics located in J-PARC, Japan, aiming to explore beyond the Standard Model by measuring branching ratio of $K_L\rightarrowπ^{0}ν\barν$ decay. This decay has not yet been observed. predicted $(3.0\pm0.3)\times10^{-11}$ and current experimental upper limit established KEK E391a $2.6\times10^{-8}$. signal signature two photons on calorimeter with no veto detectors. It also large transverse momentum due missing neutrinos. Kaons that outside beam line final...