Conveners
Scientific Program: Session 1
- Shinsuke KAWASAKI (KEK)
Scientific Program: Session2
- Takatoshi Aoki (The University of Tokyo)
Scientific Program: Session 3
- Naritoshi Kawamura (KEK/J-PARC)
Scientific Program: Session 4
- Kaori Fuyuto
Scientific Program: Session 5
- Chen-yu Liu (University of Illinois Urbana-Champaign)
Scientific Program: Session 6
- Stephan Paul
Scientific Program: Session 7
- Akira Ishida (National Institute of Advanced Industrial Science and Technology (AIST))
Scientific Program: Session 8
- Matthias R. Schindler
Scientific Program: Session 9
- Kazuki Ueno (The University of Osaka)
Scientific Program: Session 10
- Takahiko Masuda (RIIS, Okayama University)
Scientific Program: Session 11
- Volodymyr Takhistov (QUP, KEK)
Scientific Program: Session 12
- Nodoka Yamanaka (Tohoku University)
Scientific Program: Session 13
- Kenji MISHIMA (RCNP, Osaka university)
Scientific Program: Session 14
- Nicholas Hutzler (Caltech)
Scientific Program: Session 15
- Tsutomu Mibe (IPNS/KEK)
Scientific Program: Session 16
- Linus Persson (Lund University)
Scientific Program: Session 17
- Go Ichikawa (KEK)
The neutron lifetime is a fundamental parameter in nuclear and particle physics, with implications for Big Bang nucleosynthesis, weak interaction studies, and searches for new physics beyond the Standard Model. Over the past decades, increasingly precise experiments have been performed using two main approaches: the “bottle” method, which traps ultracold neutrons, and the “beam” method, which...
The ``neutron lifetime puzzle'' arises from the discrepancy between neutron lifetime measurements obtained using the beam method, which measures decay products, and the bottle method, which measures the disappearance of neutrons. To resolve this puzzle, we conducted an experiment using a pulsed cold neutron beam at J-PARC. In this experiment, the neutron lifetime is determined from the ratio...
The unitarity of the CKM quark mixing matrix can be tested by measuring the unitarity sum of the f irst row, which requires precision extraction of the first element (V$_\mathrm{ud}$). V$_\mathrm{ud}$ can be measured by combining measurement of the neutron lifetime with the axial-vector weak coupling constant. The Nab experiment, located at the Spallation Neutron Source at Oak Ridge National...
The neutron represents a versatile tool in the realm of fundamental particle physics. It is used to perform precision physics measurements at low energies with the goal to search for signals beyond the Standard Model of particle physics. In this respect, the neutron Electric Dipole Moment (EDM) has attracted interest as a promising channel for finding new physics since decades. The existence...
Recent progress of the TRIUMF Ultra Cold Advanced Neutron Source and EDM Experiment The TUCAN collaboration is commissioning a world-leading ultracold neutron (UCN) source at TRIUMF, capable of production rates up to 1.6$\times 10^7$ UCN/s once completed. Spallation neutrons are cooled in room temperature heavy water and 20K liquid deuterium, followed by UCN production in a spherical volume of...
The search for a permanent electric dipole moment of the neutron (nEDM) has been going on for over 60 years and is still a hot topic with various ongoing efforts worldwide. I will present the status of the work of the nEDM collaboration at PSI. The current best limit resulted from the previous measurement at PSI. The nEDM collaboration has developed a new apparatus 'n2EDM', which is being...
The FNAL muon g-2 experiment has measured the anomalous magnetic moment of the muon with an unprecedented precision of 127 ppb [1]. In parallel, significant theoretical efforts are underway to predict the Standard Model (SM) value of muon g-2 with comparable precision [2]. A new experiment aiming to simultaneously measure the muon g-2 and electric dipole moment (EDM), using the world’s first...
Electric dipole moments (EDM) of fundamental particles inherently violate the combined symmetry of charge-conjugation and parity inversion (CP) . At PSI we plan to measure the EDM of the muon using the frozen-spin technique within a compact storage trap. This method exploits the high effective electric field, E = 165 MV/m, experienced in the muon’s rest frame with a momentum of about 23 MeV/c...
Studies of fundamental symmetries violations in atoms and molecules provide some of the most confronting tests of the Standard Model and sensitive searches for new physics beyond. In this talk, I will focus on atomic parity violation and give the current status and key challenges of the theory. I will also discuss how atoms may be used to deduce improved nuclear physics properties, essential...
The flavor diagonal CP violation of elementary particle physics contributes to the atomic, nuclear, and nucleon electric dipole moments (EDMs), T-violating neutron scattering, and to the angular correlations of beta decay. However, its extraction from experimental data has for long been obstructed by the nonperturbative physics of quantum chromodynamics. Quite recently, there were significant...
Time Reversal Invariance Violating (TRIV) effects in neutron transmission through a nuclei target are discussed. We explore the possibility to search TRI violation using important advantages of neutron nuclei interactions: the enhancement of TRIV observables by many orders of magnitude, the measurements of relative effects (TRIV and parity violating ones at the same resonances) with a...
The fundamental parity violating effect caused by the hadronic weak interaction is enhanced by up to 10^6 times in neutron absorption reactions of 139La, 131Xe, 117Sn, and other nuclei. This enhancement can be explained by the mixing between s-wave and p-wave amplitudes of the compound nuclear state (s-p mixing model). Similarly, T-violating effect in the nucleon-nucleon interaction can also...
The GBAR experiment is designed to investigate the weak equivalence principle by measuring the free-fall acceleration of antihydrogen in the Earth gravitational field [1]. The goal is to obtain a precision of 1% in a first phase, later to be improved using quantum reflection on a surface [2]. To achieve this, the first step is to produce sympathetically coolable antihydrogen ions, through two...
In the limit of vanishing quark masses, QCD exhibits a chiral symmetry. This symmetry is not only broken explicitly by the finite physical quark masses, but is also assumed to be broken spontaneously. Chiral symmetry and its breaking form the basis of a series of effective field theories used to describe the low-energy interactions between hadrons and their coupling to external fields....
Charged lepton flavor violation (cLFV) is a clear signature of physics beyond the Standard Model (SM). While cLFV is not expected to be observed in the SM, many new physics models predict reachable branching fractions of cLFV decays in the current and future experiments. The Belle II experiment, located at the SuperKEKB asymmetric-energy e+e− collider, is a "tau factory" and is good place to...
The theory of elementary particle physics, the Standard Model (SM), provides a successful description of the basic constituents of matter and the forces acting between them. However, it explains only about 15 % of the total mass in the universe, not accounting for the dark matter postulated in the face of astrophysical and cosmological data. The study of the universe at large shows that our...
Muonium is a pure leptonic binary system consisting of a positive muon and an electron, and its level structure can be calculated with high precision. The Muonium Spectroscopy Experiment Using Microwave (MuSEUM) experiment aims to verify the quantum electromagnetic dynamics theory and determine the positive muon magnetic moment and mass by precise measurements of the ground-state hyperfine...
Microwave spectroscopy of the ground-state hyperfine structure (HFS) of muonic helium atoms is underway at J-PARC Muon Experimental Facility (MUSE) to determine the magnetic moment and mass of the negative muon with high precision. Muonic helium is a hydrogen-like atom composed of a helium atom with one of its two electrons replaced by a negative muon. Its ground-state hyperfine structure,...
It is crucial to explore physics beyond the Standard Model (BSM) because the Standard Model is incomplete in explaining questions that arise from cosmological observations, such as the existence of dark matter and the matter-antimatter asymmetry in our universe. Precise spectroscopy of muonium is a powerful way to search for BSM because of muonium’s simple energy structure. Muonium is a purely...
We present a new rigorous scheme for understanding quark confinement based on the non-perturbative vacuum disordered by some topological defects. We start from the 4-dim. Euclidean Yang- Mills theory and require the conformal equivalence between the 4- dim.Euclidean space and the possible curved spacetimes with some compact dimensions. This requirement forces us to restrict the gauge...
First principles, or ab initio, nuclear theory describes atomic nuclei as systems of nucleons interacting by QCD-based chiral effective field theory (EFT) nucleon-nucleon and three-nucleon forces. In combination with chiral EFT electroweak currents, ab initio nuclear calculations can provide model-independent results with quantifiable uncertainties relevant for tests of fundamental symmetries i...
A low energy particle confined by a horizontal reflective surface and gravity settles in gravitationally bound quantum states. These gravitational quantum states (GQS) were so far only observed with neutrons [1,2]. However, the existence of GQS is predicted also for atoms. The GRASIAN collaboration pursues the first observation of GQS of atoms, using a cryogenic hydrogen beam. This endeavor...
Positronium (Ps), a purely leptonic bound state of an electron and a positron, offers a unique platform for testing fundamental physics, including gravity on antiparticles [1] and a gamma-ray laser [2]. Achieving Bose-Einstein condensation (Ps-BEC) would be a breakthrough, requiring ultracold temperatures (approximately 10 K) and a dense state (around 10¹⁸ cm⁻³) Ps within its short lifetime of...
This talk reports the result of the search for the decay \mu+->e+\gamma undertaken at the Paul Scherrer Institut in Switzerland with the MEG II experiment using the data collected in the 2021- 2022 physics runs. The sensitivity of this search is 2.2x10-13, a factor of 2.4 better than that of the full MEG dataset and obtained in a data taking period of about one fourth that of MEG, thanks to...
The 229mTh isomeric state has the lowest known energy for a nuclear transition and is a candidate for a clock disciplined by an atomic nucleus. After demonstrating the absolute transition frequency measurement, we now move on to characterizing its environmental sensitivity as a clock, and present preliminary results regarding the effect of resonant microwaves. A clock based on this transition...
The nuclear transition between the nuclear ground state and the isomer of thorium-229 offers a unique opportunity for direct laser spectroscopy of the atomic nucleus. One of the applications is a high-accuracy nuclear clock based on the resonance frequency of this nuclear transition. We developed an ion trap for triply charged thorium-229 obtained as recoil ions from the -decay of...
We propose new axion models in which the Peccei–Quinn (PQ) symmetry is identified with baryon and/or lepton number symmetries. By extending the KSVZ axion model with higher- dimensional operators, we develop a general method to fix the baryon and lepton numbers of new scalar fields. This framework naturally predicts distinctive baryon-number violating processes such as nucleon decays,...
In the early universe, matter and anti-matter, produced equally in high-temperature density, are assumed to annihilate one another. However, the current universe is dominated by only matter. The “mystery of matter-dominated universe” is one of the big problems in particle physics and cosmology, and neutrinos are expected to be a key to the solution. More than 80 years ago, the physicist Ettore...
The European Spallation Source (ESS), currently under construction in Lund, Sweden, will become the world’s most powerful neutron research facility. The proposed NNBAR experiment aims to perform the first search in over three decades for free neutron–antineutron oscillations. Such a transformation would constitute direct evidence of baryon number violation, a phenomenon anticipated by several...
The search for the fundamental physics using atoms and molecules have been widely investigated [1]. The discovery of the electron’s electric dipole moment (EDM) sheds light on new physics beyond the standard model. The upper limit of EDM has been reported [2]. We propose a novel experimental technique to measure the electron EDM using ultracold Fr atoms based on the combined principles of...
Molecules containing radioactive nuclei are being pursued for a wide range of applications, from fundamental symmetries to nuclear astrophysics. However, their study is made challenging by the combination of limited quantity and the difficulty of working with even the simplest molecules. Here I will describe the production and spectroscopy of cold, stopped 226RaOH, 226RaOD, and 226RaF in a...
Electric dipole moments (EDMs) play a central role in searches for CP violation beyond the Standard Model.
This talk reviews activities at the COoler SYnchrotron COSY at Forschungszentrum Juelich in Germany.
A series of milestones in the preparation for electric dipole measurements
of charged hadrons in storage rings have been achieved in recent years at COSY.
These include the...
Two new tabletop measurements promise to each increase by an order of magnitude the sensitivity for testing the SM and for probing for BSM (beyond the SM). For the electron magnetic moment, a one-electron relativistic quantum cyclotron already provides the most precise measurement — the most precisely measured property of any elementary particle — to test the most precise prediction of the SM....
The standard model predicts a value for the electron’s electric dipole moment (eEDM, d$_\textrm{e}$), d$_\textrm{e}$ ~ 10$^{-35}$ e cm [1], far smaller than what is predicted by theories beyond the standard model, typically d$_\textrm{e}$ ≈ 10$^{-31}$ – 10$^{-24}$ e cm. To date, the current experimental upper limit is set at d$_\textrm{e}$ < 4.1 x 10$^{-30}$ e cm [2]. Further improvements in...
An e ective theory of charge lepton flavor violation (CLFV) was recently developed, yielding a complete set of nucleon-level operators through linear order in the nucleon and muon velocities. The embedding of this operator basis in a nucleus then determines what can and cannot be learned about CLFV from muon-to-electron conversion. Due to several technical tricks introduced, we were able to...
The COMET experiment at J-PARC aims to search for the coherent, neutrinoless conversion of a muon into an electron in the field of an aluminium nucleus. This process violates charged lepton flavor conservation and is forbidden in the Standard Model, so its observation would be a clear indication of new physics. COMET targets an ultimate single-event sensitivity of $10^{-17}$, improving the...
Neutrino oscillations have shown that lepton flavor is not a conserved quantity. Charged lepton flavor violation (CLFV) is suppressed by the small neutrino masses well below what is experimentally observable, while new physics models predict higher rates of CLFV. The CLFV μ− → e− conversion process is sensitive to a wide range of new physics models. The upcoming Mu2e experiment at FNAL will...
n this contribution I will review the experimental efforts currently operated at the antimatter factory of CERN to test the fundamental charge, parity, time reversal invariance and other fundamental symmetries using antiprotons, antiprotonic atoms, and antihydrogen. The talk will review several world-class precision spectroscopy results, including proton/antiproton charge-to-mass ratio and...
In modern physics, four fundamental interactions—electromagnetic, strong, weak, and gravitational—are being studied under a unified framework known as the Theory of Everything. Among them, gravity is significantly weaker than the others, which has been known as the hierarchy problem. One proposed solution is the Large Extra Dimension (LED) model, which suggests that additional spatial...
To experimentally make breakthroughs in exploring quantum gravity, searching for the violation of the gravitational inverse square law to probe large extra dimensions predicted by string theories, and the violation of Lorentz symmetry, is attracting significant interest. Recent progress on these fields and their interpretations will be presented in this talk. Especially, the gravitational...
