Myung-Jae Lee

We present the first results of the Fermilab National Accelerator Laboratory (FNAL) Muon g -2 Experiment for the positive muon magnetic anomaly a g -2=2. The anomaly is determined from the precision measurements of two angular frequencies. Intensity variation of high-energy positrons from muon decays directly encodes the difference frequency a between the spin-precession and cyclotron frequencies for polarized muons in a magnetic storage ring. The storage ring magnetic field is measured using nu

A distinct peak is observed in the pi +/- psi' invariant mass distribution near 4.43 GeV in B-->K pi +/- psi' decays. A fit using a Breit-Wigner resonance shape yields a peak mass and width of M=4433+/-4(stat)+/-2(syst) MeV and Gamma=45-13+18(stat)-13+30(syst) MeV. The product branching fraction is determined to be B(B 0-->K -/+Z+/-(4430)) x B(Z+/-(4430)-->pi+/-psi')=(4.1+/-1.0(stat)+/-1.4(syst)) x 10(-5), where Z+/-(4430) is used to denote the observed structure. The statistical significance of

Dark sectors charged under a new Abelian interaction have recently received much attention in the context of dark matter models. These models introduce a light new mediator, the so-called dark photon (A^{'}), connecting the dark sector to the standard model. We present a search for a dark photon in the reaction e^{+}e^{-}→γA^{'}, A^{'}→e^{+}e^{-}, μ^{+}μ^{-} using 514 fb^{-1} of data collected with the BABAR detector. We observe no statistically significant deviations from the standard model pre

Abstract The Technical Design for the COMET Phase-I experiment is presented in this paper. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus ($\mu$–$e$ conversion, $\mu^{-}N \rightarrow e^{-}N$); a lepton flavor-violating process. The experimental sensitivity goal for this process in the Phase-I experiment is $3.1\times10^{-15}$, or 90% upper limit of a branching ratio of $7\times 10^{-15}$, which is

We present a study of tau(-)->pi(-)pi(+)pi(-)nu(tau), tau(-) -> K-pi(+)pi(-)nu(tau), tau(-) -> K-K+ pi(-)nu(tau), and tau(-) -> K-K+K-nu(tau) decays using a 666 fb(-1) data sample collected with the Belle detector at the KEKB asymmetric- energy e(+)e(-) collider at and near a center- of- mass energy of 10.58 GeV. The branching fractions are measured to be B(tau(-)->pi(-)pi(+)pi(-)nu(tau)) = (8.42 +/- 0.00(-0.25)(+0.26)) x 10(-2), B(tau(-)-> K-pi(+)pi(-)nu(tau)) = 3.30 +/- 0.01(

COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of a nucleus (μ− + N → e− + N); a lepton flavor violating process. The experimental sensitivity goal for this process is order of 10^−15 for Phase-I and 10^-17 for Phase-II experiment, which is a factor of 100 to 10,000 improvements correspondingly over existing limits. Recent progresses in facility and detector development are presented, along with COMET Phase-I and Phase-

The Mu2e experiment will search for neutrinoless conversion of muons into electrons in the field of an aluminum nucleus. Precise and robust measurement of the outgoing electron momentum is an essential element to the experiment. We describe the design of a low mass tracking system to meet this requirement. We have chosen to use about 20,000 thin-walled Mylar straws held under tension to avoid the need for supports within the active volume. The electronics system enables the time-division techniq

Lepton-flavor violation (LFV) has been discovered in the neutrino sector by neutrino oscillation experiments. The minimal extension of the Standard Model (SM) to include neutrino masses allows LFV in the charged sector (CLFV) at the loop level, but at rates that are too small to be experimentally observed. Lepton-number violation (LNV) is explicitly forbidden even in the minimally extended SM, so the observation of an LNV process would be unambiguous evidence of physics beyond the SM. The search

Early-detection and monitoring of toxic chemical gas cloud with chemical detector is essential for reducing the number of casualties. Conventional method for chemical detection and reconnaissance has the limitation in approaching to chemically contaminated site and prompt understanding for the situation. Stand-off detector can detect and identify the chemical gas at a long distance but it cannot know exact distance and position. Chemical detection UAV is an emerging platform for its high mobilit

COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of a nucleus $(\mu^{-} + N \to e^- + N)$; a lepton flavor violating process. The experimental sensitivity goal for this process is of order $10^{15}$ for Phase-I and $10^{17}$ for Phase-II experiment, which is a factor of 100 to 10,000 improvements correspondingly over existing limits. Recent progress in facility and detector development are presented, along with COMET Phas