Light scalars coupled to photons and non-newtonian forces

TL;DR

It is shown that the experimental constraints on exotic, fifth-type forces lead to stringent constraints on the phigammagamma coupling, and the impact on the recent PVLAS results and the role of paraphoton models introduced to solve the PV LAS-CAST puzzle is discussed.

Abstract

A particle $φ$ coupling to two photons couples also to charged particles, like protons, through a loop. If the particle is a light scalar this induced coupling to protons leads to non-newtonian forces. We show that the experimental constraints on exotic, fifth-type forces lead to stringent constraints on the $φγγ$ coupling.

Figures (2)

• Figure 1: Loop diagram.
• Figure 2: Constraints in the $\log{M}-m_\phi$ plane. Lines labeled Earth/moon and Astr. 1998 show constraints from astrophysical observations, Refs. EarthMoon and Onofrio respectively. Lines labeled Be/Cu, Irvine, Eöt-wash, Stanford 2, Stanford 2, and Lamoreaux show experimental constraints, Refs. BeCu, Irvine, kapner, Stanford:2, Stanford:1, and Lamoreaux respectively. The shaded region is excluded.