Astrophysical axion bounds: An update
نویسنده
چکیده
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 opportunity” 10 eV ∼ < ma ∼ < 10 eV, with large uncertainties on either side, where axions could still exist and where they would provide a significant fraction or all of the cosmic dark matter. The current status of this axion window is reviewed.
منابع مشابه
Astrophysical Axion Bounds
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 lifetime of globular-cluster stars, accelerated white-dwarf cooling, and a reduction of the supernova SN 1987A neutrino burst duration. We review and update th...
متن کاملEvading the astrophysical limits on light pseudoscalars
We study the possibility of evading astrophysical bounds on light pseudoscalars by not restricting ourselves to the QCD axion. We argue that the solar bounds can be evaded if we have a sufficiently strong self coupling of the pseudoscalars and their coupling to electrons. The required couplings do not conflict with any known experimental bounds. We also require a small density of pseudoscalar p...
متن کاملThe Need for Purely Laboratory-Based Axion-Like Particle Searches
Abstract The PVLAS signal has led to the proposal of many experiments searching for light bosons coupled to photons. The coupling strength probed by these near future searches is, however, far from the allowed region, if astrophysical bounds apply. But the environmental conditions for the production of axion-like particles in stars are very different from those present in laboratories. We consi...
متن کاملEvading Astrophysical Constraints on Axion-Like Particles
Stellar energy loss arguments lead to strong constraints on the coupling φγγ of a light axion-like particle to two photons. Helioscopes, like CAST, are able to put competitive bounds. The PVLAS experiment has recently observed a rotation of the polarization of a laser propagating in a magnetic field that can be interpreted as the effect of a quite strong φγγ coupling. We present scenarios where...
متن کاملar X iv : h ep - p h / 06 05 31 3 v 1 2 9 M ay 2 00 6 DESY 06 - 068 We need lab experiments to look for axion - like particles
The PVLAS signal has renewed the interest in light bosons coupled to the electromagnetic field. However, astrophysical bounds coming from the lifetime of the sun and the CAST experiment are seemingly in conflict with this result. We discuss effective models that allow to suppress production of axion-like particles in the sun and thereby relax the bounds by some orders of magnitude. This stresse...
متن کامل