235 citations · 2.2k across the 57 of their papers we have counts for
52 papers · 1 filter
New physics in multi-lepton tau decays
Yohei Ema, Patrick J. Fox, Matheus Hostert +4
Dark particles with lepton-flavor-violating couplings to the tau lepton can induce rare neutrinoless decays with large final state multiplicities. We study models where transit…
Long-lived Axion-Like Particles from Tau Decays
Yohei Ema, Patrick J. Fox, Matheus Hostert +4
Axion-like particles (ALPs) are well-motivated examples of light, weakly coupled particles in theories beyond the Standard Model. In this work, we study long-lived ALPs coupled exc…
Spontaneous Magnetogenesis at the Electroweak Phase Transition
Valerie Domcke, Yohei Ema, Teerthal Patel
Spontaneous CP violation during the electroweak phase transition can induce a twisting of the magnetic field configuration of Standard Model dumbbells, resulting in sizable interga…
Momentum shift and on-shell recursion relation for electroweak theory
Yohei Ema, Ting Gao, Wenqi Ke +3
We study the All-Line Transverse (ALT) shift which we developed for on-shell recursion of amplitudes for particles of any mass. We discuss the validity of the shift for general the…
Chiral properties of the nucleon interpolating current and -dependent observables
Yohei Ema, Ting Gao, Maxim Pospelov +1
We revisit the chiral properties of nucleon interpolating currents, and show that of the two leading order currents and , only two linear combinations trans…
Dark Matter Catalyzed Baryon Destruction
Yohei Ema, Robert McGehee, Maxim Pospelov +1
WIMP-type dark matter may have additional interactions that break baryon number, leading to induced nucleon decays which are subject to direct experimental constraints from proton…
Inflaton decay in No-Scale Supergravity and Starobinsky-like models
Yohei Ema, Marcos A. G. Garcia, Wenqi Ke +2
We consider the decay of the inflaton in Starobinsky-like models arising from either an theory of gravity or no-scale supergravity models. If Standard Model matter is…
Momentum shift and on-shell constructible massive amplitudes
Yohei Ema, Ting Gao, Wenqi Ke +3
We construct tree-level amplitude for massive particles using on-shell recursion relations based on two classes of momentum shifts: an all-line transverse shift that deforms moment…
Probing Earth-Bound Dark Matter with Nuclear Reactors
Yohei Ema, Maxim Pospelov, Anupam Ray
Strongly-interacting dark matter can be accumulated in large quantities inside the Earth, and for dark matter particles in a few GeV mass range, it can exist in large quantities ne…
Cosmological Collider Signatures of Higgs- Inflation
Yohei Ema, Sarunas Verner
We study the cosmological collider signatures in the Higgs- inflation model. We consider two distinct types of signals: one originating from the inflaton coupling to Standard…
Muon spin force
Yohei Ema, Ting Gao, Maxim Pospelov
Current discrepancy between the measurement and the prediction of the muon anomalous magnetic moment can be resolved in the presence of a long-range force created by ordinary atoms…
Searching for axions with kaon decay at rest
Yohei Ema, Zhen Liu, Ryan Plestid
We describe a novel search strategy for axions (or hadronically coupled axion-like particles) in the mass range of . The search relies on kaon decay at…
Heavy Neutral Leptons from Stopped Muons and Pions
Yohei Ema, Zhen Liu, Kun-Feng Lyu +1
Stopped muons, which are generic in pion-at-rest experiments, can shed light on heavy neutral leptons (HNLs) in unexplored parameter spaces. If the HNL is lighter than the muon, th…
Zero Casimir Force in Axion Electrodynamics and the Search for a New Force
Yohei Ema, Masashi Hazumi, Hideo Iizuka +2
We point out that there is a stable configuration of metal plates where the Casimir force is vanishing in axion electrodynamics. We consider a concrete setup involving Weyl semimet…
Flavor-changing light bosons with accidental longevity
Yohei Ema, Zhen Liu, Kun-Feng Lyu +1
We consider a model with a complex scalar field that couples to or within the "longevity" window: in which and $l_2…
Reevaluation of heavy-fermion-induced electron EDM at three loops
Yohei Ema, Ting Gao, Maxim Pospelov
Motivated by improved limits on electric dipole moments (EDMs), we revisit the three-loop light-by-light mechanism that transmits violation from a heavy fermion to a light one…
Improved indirect limits on charm and bottom quark EDMs
Yohei Ema, Ting Gao, Maxim Pospelov
We derive indirect limits on the charm and bottom quark electric dipole moments (EDMs) from paramagnetic AMO and neutron EDM experiments. The charm and bottom quark EDMs generate $…
Transient phenomena in the axion assisted Schwinger effect
Valerie Domcke, Yohei Ema, Kyohei Mukaida
Particle production induced by a time-dependent background is well understood as the projection of the time-evolved initial state onto a set of final states. While the asymptotic i…
Standard Model prediction for paramagnetic EDMs
Yohei Ema, Ting Gao, Maxim Pospelov
Standard Model violation associated with the phase of the Cabibbo-Kobayashi-Maskawa quark mixing matrix is known to give small answers for the EDM observables. Moreover, predi…
Scalar field couplings to quadratic curvature and decay into gravitons
Yohei Ema, Kyohei Mukaida, Kazunori Nakayama
Any field, even if it lives in a completely hidden sector, interacts with the visible sector at least via the gravitational interaction. In this paper, we show that a scalar field…
Improved indirect limits on muon EDM
Yohei Ema, Ting Gao, Maxim Pospelov
Given current discrepancy in muon and future dedicated efforts to measure muon electric dipole moment (EDM) , we assess the indirect constraints imposed on by the…
Preheating from target space curvature and unitarity violation: Analysis in field space
Yohei Ema, Ryusuke Jinno, Kazunori Nakayama +1
We study particle production and unitarity violation caused by a curved target space right after inflation. We use the inflaton field value instead of cosmic time as the time varia…
Axion assisted Schwinger effect
Valerie Domcke, Yohei Ema, Kyohei Mukaida
We point out an enhancement of the pair production rate of charged fermions in a strong electric field in the presence of time dependent classical axion-like background field, whic…
Neutrino experiments probe hadrophilic light dark matter
Yohei Ema, Filippo Sala, Ryosuke Sato
We use Super-K data to place new strong limits on interactions of sub-GeV Dark Matter (DM) with nuclei, that rely on the DM flux inevitably induced by cosmic-ray upscatterings. We…