相关论文: Neutron star cooling with lepton-flavor-violating …
If axions exist, they are copiously produced in hot and dense plasmas, carrying away energy directly from the interior of stars. Various astronomical observables constrain the operation of such anomalous stellar energy-loss channels and…
Compact objects such as neutron stars and white dwarfs can source axion-like particles and QCD axions due to CP-violating axion-fermion couplings. The magnitude of the axion field depends on the stellar density and on the strength of the…
Axions are hypothetical particles proposed to solve the strong CP problem in QCD and may constitute a significant fraction of the dark matter in the Universe. Axions are expected to be produced in neutron stars and subsequently decay,…
Polarization measurements of thermal radiation from magnetic white dwarf (MWD) stars have been proposed as a probe of axion-photon mixing. The radiation leaving the surface of the MWD is unpolarized, but if low-mass axions exist then…
We present constraints on the nature of axions and axionlike particles (ALPs) by analyzing gamma--ray data from neutron stars using the Fermi Large Area Telescope. In addition to axions solving the strong CP problem of particle physics,…
We present a theoretical model for detecting axions from neutron stars in a QCD phase of quark matter. The axions would be produced from a quark-antiquark pair $u\bar{u}$ or $d\bar{d}$, in loop(s) involving gluons. The chiral anomaly of QCD…
The implications of hyperon pairing for the thermal evolution of neutron stars containing hyperons are investigated. The outcome of cooling simulations are compared for neutron star models composed only of nucleons and leptons, models…
Axions, if realized in nature, can be copiously produced in the early universe via thermal processes, contributing to the mass-energy density of thermal hot relics. In light of the most recent cosmological observations, we analyze two…
We investigate axion emission from singlet proton Cooper pairs in neutron stars, a process that dominates axion emission in young neutron stars in the KSVZ model. By re-deriving its emissivity, we confirm consistency with most existing…
Ultralight bosons such as axions and dark photons are well-motivated hypothetical particles, whose couplings to ordinary matter can be effectively constrained by stellar cooling. Limits on these interactions can be obtained by demanding…
Neutron stars (NS's) with their strong magnetic fields and hot dense cores could be powerful probes of axions, a classic benchmark of feebly-coupled new particles, through abundant production of axions with the axion-nucleon coupling and…
We study magnetic conversion of ultra-relativistic axion-like particles (ALPs) into photons in compact-star environments, focusing on the hot, transient conditions of core-collapse supernova (SN) remnants and neutron-star mergers (NSMs). We…
Core-collapse supernovae are a useful laboratory to probe the nature of exotic particles. If axionlike particles (ALPs) are produced in supernovae, they can affect the transfer of energy and leave traces in observational signatures. In this…
The parameter space of massive axion-like-particles (ALPs) with $m_a \sim {\mathcal O} (100)$ MeV and coupled with nucleons is largely unexplored. Here, we present new constraints in this parameter region. In doing so, we characterize the…
In the ALP model, lepton flavor violation (LFV) can arise from off-diagonal ALP-lepton couplings ($g_{a\ell_i\ell_j}$), which are absent in the Standard Model. We focus on ALP production via gluon fusion ($pp \to a$) at the Large Hadron…
We perform general relativistic one-dimensional supernova (SN) simulations to identify observable signatures of enhanced axion emission from the pion-induced reaction $\pi^- + p \rightarrow n + a$ inside a newly born protoneutron star…
We analyze 9 years of PASS 8 $\textit{Fermi}$-LAT data in the 60$-$500 MeV range and determine flux upper limits (UL) for 17 gamma-ray dark pulsars as a probe of axions produced by nucleon-nucleon Bremsstrahlung in the pulsar core. Using a…
We investigate the effect of the axion cooling on the nucleosynthesis in a massive star with $16M_{\odot}$ by standard stellar evolution calculation. We find that the axion cooling suppresses the nuclear reactions in carbon, oxygen and…
Compact stellar objects like supernovae and neutron stars are believed to cool by emitting axions predominantly via axion bremsstrahlung ($NN \to NNa$), pion conversion ($\pi^- p^+ \to N a$) and photo-production ($\gamma N \to N a$). In…
We report on a search for ultra-low-mass axion-like dark matter by analysing the ratio of the spin-precession frequencies of stored ultracold neutrons and $^{199}$Hg atoms for an axion-induced oscillating electric dipole moment of the…