7 papers · 1 filter
Completing Axion Double Level Crossings
Hai-Jun Li, Wei Chao, Huai-Ke Guo +1
In this work, we present the refinement of axion double level crossings within the context of multi-axion mass mixing, specifically focusing on cases where the number of axions exc…
Axion effects on gamma-ray spectral irregularities. II: Implications of EBL absorption
Hai-Jun Li, Wei Chao, Xiu-Hui Tan +1
The extragalactic background light (EBL) plays a crucial role in the propagation of high-energy particles throughout the Universe. In this work, we explore the impact of the EBL ab…
Mass Mixing between QCD Axions
Hai-Jun Li, Yu-Feng Zhou
We introduce a novel level crossing phenomenon in the mass mixing between the QCD axions, one canonical QCD axion and one axion. The level crossing can take place…
Upper limit on the axion-photon coupling from Markarian 421
Hai-Jun Li, Wei Chao, Yu-Feng Zhou
Markarian 421 is a well-known nearby BL Lac blazar at the redshift . Many previous works were investigated to constrain the axion-photon coupling from its TeV gamma-ray ob…
Gravitational waves and primordial black holes from axion domain walls in level crossing
Hai-Jun Li, Yu-Feng Zhou
In this paper, we investigate the nano-Hertz gravitational waves (GWs) emission and the massive primordial black holes (PBHs) formation from the light QCD axion scenario. We consid…
Light QCD Axion Dark Matter from Double Level Crossings
Hai-Jun Li, Ying-Quan Peng, Wei Chao +1
The even light QCD axion called the axion can both solve the strong CP problem and account for the dark matter (DM). We point out that the single and double level…