Chameleon foreCAST

Abstract

Dark energy models, such as the chameleon, where the acceleration of the expansion of the universe results from the dynamics of a scalar field coupled to matter, suffer from the potential existence of a fifth force. Three known mechanisms have been proposed to restore General Relativity in the solar system and the laboratory, which are the symmetron/Damour-Polyakov effect, the Vainshtein property and the chameleon screening. Here, we propose to probe the existence of chameleons in the laboratory, considering their particle physics consequences. We envisage the resonant and non-resonant production of chameleons in the sun and their back-conversion into X-ray photons in a solar helioscope pipe such as the one used by CAST. A detection of these X-rays would indicate the existence of chameleons. We focus on a template model for the solar magnetic field: a constant magnetic field in a narrow shell surrounding the tachocline. The X-ray photons in a helioscope pipe obtained from back-conversion of the chameleons created inside the sun have a spectrum which is peaked in the sub-keV region, just below the actual sensitivity range of the present axion helioscopes. Nevertheless they are detectable by present day magnetic helioscopes like CAST and Sumico, which were built originally for solar axions. We also propose a chameleon-through-a-wall experiment whereby X-ray photons from a synchroton radiation source could be converted into chameleons inside a dipole magnet, then pass a wall which is opaque to X-rays before being back-converted into X-ray photons in a second magnet downstream. We show that this could provide a direct signature for the existence of chameleon particles.

new title, matches published version, 22 pages, 13 figures

References in corpus (12)

• Dynamics of dark energy
• Evading Equivalence Principle Violations, Cosmological and other Experimental Constraints in Scalar Field Theories with a Strong Coupling to Matter
• Environmental Dependence of Masses and Coupling Constants
• The Dilaton and Modified Gravity
• Probing eV-scale axions with CAST
• Strongly Coupled Chameleon Fields: New Horizons in Scalar Field Theory
• CAST search for sub-eV mass solar axions with 3He buffer gas
• Compatibility of the chameleon-field model with fifth-force experiments, cosmology, and PVLAS and CAST results
• Strongly Coupled Chameleons and the Neutronic Quantum Bouncer
• Testing Chameleon Theories with Light Propagating through a Magnetic Field
• Laboratory constraints on chameleon dark energy and power-law fields
• Anomalous coupling of scalars to gauge fields

Cited by in corpus (17)

• Experimental Searches for the Axion and Axion-like Particles
• Direct detection of dark energy: the XENON1T excess and future prospects
• Symmetron dark energy in laboratory experiments
• Search for chameleons with CAST
• Axion Astrophysics
• Detecting solar chameleons through radiation pressure
• Improved Search for Solar Chameleons with a GridPix Detector at CAST
• Designing dark energy afterglow experiments
• Light bosons and photospheric solutions to the solar abundance problem
• Solar chameleons: Novel channels
• Imprints of screened dark energy on nonlocal quantum correlations
• Chameleon Fragmentation
• Standard Electroweak Interactions in Gravitational Theory with Chameleon Field and Torsion
• One-electron atoms in screened modified gravity
• First Results on the Search for Chameleons with the KWISP Detector at CAST
• Chameleon fields and solar physics
• Signatures of Solar Chameleons in the Earth's Magnetic Field