相关论文: New constraints for heavy axion-like particles fro…
The standard model (SM) of particle physics is spectacularly successful, yet the measured value of the muon anomalous magnetic moment $(g-2)_\mu$ deviates from SM calculations by 3.6$\sigma$. Several theoretical models attribute this to the…
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…
Candidate astrophysical acceleration sites capable of producing the highest energy cosmic rays (E > 10^{19.5} eV) appear to be at far greater distances than is compatible with their being known particles. The properties of a new particle…
The observed properties of stars and especially the neutrino signal of the supernova 1987A provide an upper limit to the axion mass, while the age and expansion rate of the universe provide a lower limit. There remains a "window of…
High energy photons originating from the Galactic Center (GC) region have the potential to undergo significant photon-axion-like particle (ALP) oscillation effects, primarily induced by the presence of intense magnetic fields in this…
If massless leptonic photons associated to electron, muon or tau leptonic number exist they would have been emitted from supernova 1987a via the annihilation process $\nu\bar{\nu}\to\gamma_{l}\gamma_{l}$. By requiring that this process does…
Axion emission by hot and dense plasmas is a new energy-loss channel for stars. Observational consequences include a modification of the solar sound-speed profile, an increase of the solar neutrino flux, a reduction of the helium-burning…
Axions and other light particles appear ubiquitously in physics beyond the Standard Model, with a variety of possible couplings to ordinary matter. Cosmology offers a unique probe of these particles as they can thermalize in the hot…
We estimate the production rate of axion-type particles in the core of the Earth, at a temperature T~5000K. We constrain thermal geo-axion emission by demanding a core-cooling rate less than 100K/Gyr, as suggested by geophysics. This yields…
Up to date, there is no consensus regarding the origin of ultra-high energy cosmic rays (UHECR) beyond the Greisen--Zatsepin--Kuzmin (GZK) limit. In order for these UHECRs to reach the Earth, an extremely suppressed interaction between them…
The upper bound on the number of relativistic species present at nucleosynthesis has been used to constrain particles with electric charge $\epsilon e$ ($10^{-8} < \epsilon <1$). We correct the bound previously calculated for milli-charged…
New exotic particles with MeV masses, such as axion-like particles or light dark matter, can be emitted from core-collapse supernovae (SNe) with semi-relativistic velocities. Due to their speed dispersion, they would arrive at Earth as an…
The formation of a hot and dense core in a core-collapse supernova (SN) can produce massive Beyond Standard Model (BSM) particles. These particles can decay in the stellar envelope, generating positrons either directly or through secondary…
We present a long-exposure (~10 hr) image of the supernova (SN) remnant Cassiopeia A (Cas A) obtained with the UKIRT 3.8-m telescope using a narrow band filter centered at 1.644 um emission. The passband contains [Fe II] 1.644 um and [Si I]…
Protons with energies up to 10^15 eV are the main component[1] of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking[2]. Electrons are known to be accelerated to…
Studies of axion-like particles (ALPs) commonly focus on a single type of interaction, for example couplings only to photons. Most ALP models however predict correlations between different couplings, which change the phenomenology in…
High-energy photons may oscillate with axion-like particles (ALPs) when they propagate through the Milky Way's magnetic field, resulting in an alteration in the observed photon energy spectrum. The ultra-high energy gamma-ray spectra,…
Supernova (SN) 1987A is a celebrated laboratory in searches for gamma-ray flashes produced by the radiative decay of sub-GeV particles such as axion-like particles (ALPs), sterile neutrinos, and novel gauge bosons. At large couplings,…
We investigate the prospect of an alternative laboratory-based search for the coupling of axions and axion-like particles to photons. Here, the collision of two laser beams resonantly produces axions, and a signal photon is detected after…
Active galactic nuclei (AGN) are believed to be the source of ultra high energy cosmic rays (UHECRs). Particles are assumed to be accelerated in the accretion disk and the plasma jets, produced due to conservation of angular momentum, to…