Conveners
Working Group 4: Muon Physics-1
- MyeongJae Lee (Institute for Basic Science (Korea))
Working Group 4: Muon Physics-2
- Iuri Oksuzian (UVa)
Working Group 4: Muon Physics-3
- Simon Corrodi
Working Group 4: Muon Physics-4
- Akira Sato (Osaka university)
Working Group 4: Muon Physics-5
- MyeongJae Lee (Institute for Basic Science (Korea))
Working Group 4: Muon Physics-6
- Iuri Oksuzian (UVa)
Description
Muon Physics
I will talk about the current status of the Standard Model (SM) prediction for the muon g-2. Currently, there is more than 3.5 sigma discrepancy between the experimental value of the muon g-2 and the SM prediction for it. In the SM prediction, the hadronic contribution is the largest source of the uncertainty. The leading-order (LO) hadronic contribution, which is one of the most uncertain...
The measurement of the anomalous muon magnetic moment, $a_{\mu} \equiv (g_{ \mu}-2)/2$, more than a decade ago by the Brookhaven (BNL) E821 experiment differs at a 3.7$\sigma$ level from the theoretical predictions from the Standard Model (SM). This result is among the largest observed deviations from the SM and comprises a hint of physics beyond the Standard Model.
The new Muon g-2...
The anomalous magnetic moment of muon can be calculated by the Standard Model (SM) that takes into account quantum electrodynamics (QED), electroweak, and hadronic contributions, however, the current experimental results do not agree with the theoretical expectation by more than 3$\sigma$. This may imply a presence of the New Physics, therefore, precision measurements of the muon anomaly is...
Muonium is the bound state of a positive muon and an electron. Muonium Spectroscopy Experiment Using Microwave (MuSEUM) is a new precise measurement of muonium hyperfine structure (MuHFS) at Japan Proton Accelerator Research Complex (J-PARC).
There are two major motivations for this new measurement.
- Test of the bound-state Quantum Electrodynamics (QED). Muonium is a purely leptonic...
The MUSE experiment at PSI is part of a suite of experiments that aim to resolve the proton radius puzzle that has surfaced over the past decade. MUSE is particularly interesting because it attempts to determine the proton radius through simultaneous measurements of muon-proton scattering and electron-proton scattering, in addition to performing these reactions with positive and negative...
The NA62 experiment at the CERN SPS is designed to measure the branching ratio of the K+โฯ+vv decay, very precisely predicted below 10exp[-10] by the SM. NA62 took data in 2016-2018 and collected a large sample of charged kaon decays into final states with multiple charged particles. The sensitivity to a range of lepton flavour and lepton number violating kaon decays provided by this data set...
The concept of lepton universality, where the muon and tau particles are simply heavier copies of the electron, is a key prediction in the Standard Model (SM). In models beyond the SM, lepton universality can be naturally violated with new physics particles that couple preferentially to the second and third generation leptons. Over the last few years, several hints of lepton universality...
Physics beyond the Standard Model could manifest itself through effects on lepton universality or flavour anomalies, such as the ones hinted at by flavour factories. Lepton-flavour violation (LVF) would be a striking signature of such new physics; the ATLAS experiment has multiple searches for such signal in the decay of the Higgs boson, the Z boson and of a heavy neutral gauge boson, Z'....
The Mu3e experiment will search for the charged lepton flavor violating decay $\mu^+\rightarrow e^+e^-e^+$ with a targeted branching ratio sensitivity of $10^{-16}$. The sensitivity goal drives the experimental design: To distinguish the neutrinoless signal decay from background processes, excellent momentum, vertex and time resolutions of the detector system are required. An ultra-thin...
The MEG II experiment at Paul Scherrer Institute (PSI) in Switzerland intends to achieve a sensitivity to search for muon decay to electron and gamma as good as 6x10^{-14}. The detector upgrade from the MEG experiment, which set the limit of 4.2x10^{-13} at 90% C.L., is intensively in progress toward the start of physics data acquisition in 2020. We present the status and plan of MEG II exerpiment.
The DeeMe experiment is planned to search for muon-to-electron conversion at J-PARC MLF. Our goal is to measure the process with a single event sensitivity of $1 \times 10^{-13}$ or $2 \times 10^{-14}$ for a graphite or silicon carbide target. That is one or two orders of magnitude better than the current upper limits, $7 \times 10^{-13}$ for a gold target by the SINDRUM-II experiment at PSI...
As the lepton number and lepton flavor are conserved quantities in Standard Model, observation of charged lepton flavor violation (cLFV) process will provide clues on beyond-Standard model theories. COMET is an experiment at J-PARC, Japan, which will search for neutrinoless conversion of muons into electrons in the field of a nucleus (ฮผโ + N โ eโ + N); a lepton flavor violating process. The...
The Mu2e experiment will measure the charged-lepton flavor violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of a nucleus. Mu2e will improve the previous measurement by four orders of magnitude, reaching a 90% C.L. sensitivity to CLFV conversion rates of $8\times10^{-17}$ or larger. The experiment will reach mass scales of nearly $10^4$ TeV, far beyond...
The charged lepton flavor violation (CLFV) is a good probe to search for new physics beyond the standard model. If there is a neutral boson X which is lighter than muon and has CLFV interaction, a muon can decay into an electron and an X, i.e. $\mu\to eX$. The search for this process is expected to constraint the property of X. In this talk, we focus on a search for the rare decay of muon in a...
COMET (J-PARC) and Mu2e (Fermilab) are two experiments currently under construction that aspire to discover the neutrino-less muon to electron conversion BSM process. As a cooperation between the two experiments, AlCap was created to measure low energy particle emission spectra after nuclear muon capture in target materials aluminium and titanium. These measurements are important for...
The Belle II experiment at the SuperKEKB energy-asymmetric $e^+ e^-$ collider is a substantial upgrade of the B factory facility at the Japanese KEK laboratory. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. With this data set, Belle II will be able to measure...
The Belle II experiment is a substantial upgrade of the Belle detector and will operate at the SuperKEKB energy-asymmetric $e^+ e^-$ collider. The design luminosity of the machine is $8\times 10^{35}$ cm$^{-2}$s$^{-1}$ and the Belle II experiment aims to record 50 ab$^{-1}$ of data, a factor of 50 more than its predecessor. From February to July 2018, the machine has completed a commissioning...
The J-PARC muon facility is trying to improve the sophistication of muon beam, so that we can respond to requests of material property study and particle physics study, or we can explore a brand new frontier of the usage of muon beam. I will focus on a development of slow negative muon beam in my talk.
It is an unsolved problem of prime importance whether the neutrinos are Dirac or Majorana paricles. The Majoranality of neutrinos is predicted in the presence of V+A interactions. It appeares as a time-reversal (T) symmetry breaking term in the general form of the differential decay rate of muons [1]. Positrons from muon decays are mostly polarized in the longitudinal direction. However, the...
We consider a hybrid setup consisting of neutrino data from T2HK along with antineutrinos from a muon decay-at-rest (muDAR) source. Such a setup has already been studied before in the context of standard oscillations. We now explore the ability of this setup to measure charged-current non-standard interactions (NSIs) of neutrinos that can affect the production and detection of neutrinos. We...
We investigate invisible decays of the third neutrino mass eigenstate in future accelerator neutrino experiments using muon-decay beams such as MuOn-decay MEdium baseline NeuTrino beam experiment (MOMENT). MOMENT has outstanding potential to measure the deficit or excess in the spectra caused by neutrino decays, especially in muon neutrino/antineutrino disappearance channels. Such an...
