242 citations · 530 across the 18 of their papers we have counts for
17 papers · 1 filter
Nuclear Recoils from Invisible Neutron-Pair Annihilation and the LZ event
Junseok Lee, Fuminobu Takahashi, Yu-Dai Tsai
Two bound neutrons can annihilate into a single invisible scalar carrying baryon number two, producing a monochromatic nuclear recoil. Pair removal connects the ground states…
Axion Isocurvature Perturbations Survive the Scaling Evolution of Axion Domain Walls
Naoya Kitajima, Junseok Lee, Kai Murai +2
We revisit the evolution of axion domain walls seeded by inflationary fluctuations. In our previous work, we showed that such domain-wall networks retain superhorizon correlations…
Multi-field oscillons/I-balls in the Friedberg-Lee-Sirlin model
Kai Murai, Tatsuya Ogawa, Fuminobu Takahashi
We study oscillon/I-ball solutions in a real scalar version of the Friedberg-Lee-Sirlin (FLS) model. Using the multiple-scale analysis, we derive the conditions for oscillon soluti…
Number Theory in Quantum Physics: Minicharged Particles and the Prouhet-Tarry-Escott Problem
Junseok Lee, Fuminobu Takahashi, Yu-Dai Tsai
In quantum gauge theories, anomaly cancellation severely restricts the allowed patterns of chiral charges. Here we show that, in a phenomenologically motivated framework for light…
Sign-Flipping Axion Potentials via Kapitza-Type Modulation by Heavy Axions
Kai Murai, Fuminobu Takahashi, Kosei Tomiyama
We show that the potential of a light axion can flip sign, or even nearly vanish, as a result of coherent oscillations of a heavier axion with which it mixes. This phenomenon is an…
Resolving the QCD Axion Domain Wall Problem with a Light Axion
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We propose two novel solutions to the domain wall problem of the QCD axion by introducing a massless or light axion that also couples to gluons. The first solution applies when the…
Q-balls Under Spontaneously Broken U(1) Symmetry
Masahiro Kawasaki, Kai Murai, Fuminobu Takahashi
We study the evolution of Q-balls under a spontaneously broken global symmetry. Q-balls are stabilized by the conservation of charge, but when the symmetry is spontan…
Why ? Anthropic Selection in a + Axion Dark Energy Model
Kai Murai, Fuminobu Takahashi
We study a dark energy model composed of a bare negative cosmological constant and a single ultra-light axion, motivated by the string axiverse. Assuming that intelligent observers…
Isotropic cosmic birefringence from string axion domain walls without cosmic strings, and DESI results
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
Recently, results from the Atacama Cosmology Telescope (ACT) DR6 have shown a preference for isotropic cosmic birefringence, consistent with previous analyses based on Planck and W…
QCD Axion Dark Matter from level crossing with refined adiabatic condition
Kai Murai, Yuma Narita, Fuminobu Takahashi +1
We investigate the level-crossing phenomenon in two-axion systems, where the mass eigenvalues intersect as the mass of one axion increases with the cooling of the universe. This ph…
A Bound on Light Dark Photon Dark Matter
Naoya Kitajima, Shota Nakagawa, Fuminobu Takahashi +1
We derive a bound on dark photon dark matter scenarios where the dark photon mass is generated through the Higgs mechanism, based on the requirement that symmetry breaking must occ…
More is Different: Multi-Axion Dynamics Changes Topological Defect Evolution
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We study topological defects in multi-axion models arising from multiple Peccei-Quinn (PQ) scalars. Using a simplified two-axion system, we reveal fundamental differences in the ev…
Induced Domain Walls of QCD Axion, and Gravitational Waves
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We show that heavy axion domain walls induce domain walls of the QCD axion through a mixing between the heavy axion and the QCD axion, even when the pre-inflationary initial condit…
Bubble Misalignment Mechanism for Axions
Junseok Lee, Kai Murai, Fuminobu Takahashi +1
We study the dynamics of axions at first-order phase transitions in non-Abelian gauge theories. When the duration of the phase transition is short compared to the timescale of the…
Stability of domain walls with inflationary fluctuations under potential bias, and gravitational wave signatures
Naoya Kitajima, Junseok Lee, Fuminobu Takahashi +1
A recent study has shown that domain walls with inflationary initial fluctuations exhibit remarkable stability against population bias due to long-range correlations, challenging t…
Dissipation of axion energy via the Schwinger and Witten effects
Kwang Sik Jeong, Shota Nakagawa, Fuminobu Takahashi +1
In the presence of an anomalous CP phase in a U(1) gauge theory, a monopole becomes a dyon via the Witten effect. When the anomalous CP phase is promoted to a dynamical field, the…
Physics potential of the International Axion Observatory (IAXO)
E. Armengaud, D. Attie, S. Basso +88
We review the physics potential of a next generation search for solar axions: the International Axion Observatory (IAXO). Endowed with a sensitivity to discover axion-like particle…