Testing chameleon theories with light propagating through a magnetic field

Philippe Brax, Carsten van de Bruck, Anne-Christine Davis, David F. Mota, and Douglas Shaw

Phys. Rev. D 76, 085010 – Published 15 October 2007

Abstract

It was recently argued that the observed PVLAS anomaly can be explained by chameleon field theories in which large deviations from Newton’s law can be avoided. Here we present the predictions for the dichroism and the birefringence induced in the vacuum by a magnetic field in these models. We show that chameleon particles behave very differently from standard axionlike particles (ALPs). We find that, unlike ALPs, the chameleon particles are confined within the experimental setup. As a consequence, the birefringence is always bigger than the dichroism in PVLAS-type experiments.

Received 18 July 2007

DOI:https://doi.org/10.1103/PhysRevD.76.085010

Authors & Affiliations

Philippe Brax¹, Carsten van de Bruck², Anne-Christine Davis³, David F. Mota⁴, and Douglas Shaw⁵

¹Service de Physique Théorique CEA/DSM/SPhT, Unité de recherche associée au CNRS, CEA-Saclay F-91191 Gif-sur-Yvette cedex, France
²Department of Applied Mathematics, The University of Sheffield, Hounsfield Road, Sheffield S3 7RH, United Kingdom
³Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, Cambridge CB2 0WA, United Kingdom
⁴Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 16/19, D-69120 Heidelberg, Germany
⁵Centre for Mathematical Sciences, Cambridge CB2 0WA, United Kingdom

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Issue

Vol. 76, Iss. 8 — 15 October 2007

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Images

Figure 1
Illustration of the difference between a sharp (steplike) change in the chameleon mass at the surface of the mirror and the more realistic $m_{ϕ} \sim O (1 / d)$ , for $d ≫ 1 / m_{c}$ , behavior, where $d$ is the distance from the surface of the mirror. In both of these sketches, $m_{c}$ is the chameleon mass inside the mirror and $m_{b}$ is the chameleon mass far from the mirror. The dotted line indicates the surface of the mirror.Reuse & Permissions
Figure 2
Predictions for rotation (upper plot) and ellipticity (lower plot) in the chameleon model as a function of $M$ and $m_{ϕ}$ . The PVLAS setup is used ( $L = 100 cm$ , $d = 270 cm$ , $ω = 1.2 eV$ , $B = 5 T$ , and $φ = π / 4$ ). Furthermore, we have chosen $n = 1$ .Reuse & Permissions
Figure 3
Predictions for rotation (left) and ellipticity (right) in the chameleon model as a function of $M$ for $Λ = 2.3 \times 10^{- 3} eV$ and $n = 1$ . Predictions for the 2.3 T PVLAS ( $L = 100 cm$ , $d = 270 cm$ , $ω = 1.2 eV$ , $B = 2.3 T$ , $ρ_{gas} = 2 \times 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ) and Q&A ( $L = 60 cm$ , $d = 145 cm$ , $ω = 1.2 eV$ , $B = 2.3 T$ , $ρ_{gas} = 8.5 \times 10^{- 9} {gcm}^{- 3}$ , and $φ = π / 4$ ) setups are shown. The thin dotted lines show the 95% confidence upper bounds on both the rotation and the ellipticity.Reuse & Permissions
Figure 4
Predictions for rotation (left) and ellipticity (right) in the chameleon model as a function of $M$ for $Λ = 2.3 \times 10^{- 3} eV$ and $n = 1$ . Predictions for the $B = 2.3 T$ and $B = 5.5 T$ PVLAS ( $L = 100 cm$ , $d = 270 cm$ , $ω = 1.2 eV$ , $ρ_{gas} = 2 \times 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ) and BMV ( $L = 50 cm$ , $d = 85 cm$ , $ω = 1.2 eV$ , $B = 11.5 T$ , $ρ_{gas} \approx 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ) setups are shown. The thin dotted lines show the 95% confidence upper bounds on both the rotation and the ellipticity.Reuse & Permissions
Figure 5
Predictions for rotation (left) and ellipticity (right) in the chameleon model as a function of $M$ for $Λ = 2.3 \times 10^{- 3} eV$ and $n = 1$ . Predictions for the $B = 2.3 T$ PVLAS ( $L = 100 cm$ , $d = 270 cm$ , $ω = 1.2 eV$ , $ρ_{gas} = 2 \times 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ) and BRFT ( $B = 2 T$ , $L = 800 cm$ , $d = 345 cm$ , $ω = 2.41 eV$ , $ρ_{gas} \approx 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ) setups are shown. The thin dotted lines show the 95% confidence upper bounds on both the rotation and the ellipticity.Reuse & Permissions
Figure 6
Predictions for rotation (left) and ellipticity (right) in the chameleon model as a function of $M$ for $Λ = 2.3 \times 10^{- 3} eV$ and different values of $n$ . The PVLAS setup is used ( $L = 100 cm$ , $d = 270 cm$ , $ω = 1.2 eV$ , $B = 5 T$ , $ρ_{gas} = 2 \times 10^{- 14} {gcm}^{- 3}$ , and $φ = π / 4$ ).Reuse & Permissions

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