Light scalars coupled to photons and non-newtonian forces

Area of Science:

• Particle Physics
• Cosmology
• Experimental Physics

Background:

• A light scalar particle (phi) can couple to two photons (phigammagamma).
• This coupling can induce radiative interactions with charged particles, such as protons.
• Such interactions may manifest as spin-independent non-Newtonian forces.

Purpose of the Study:

• To investigate the constraints imposed by experimental searches for exotic fifth-type forces on the phigammagamma coupling.
• To analyze the implications of these constraints on recent experimental results, specifically the PVLAS experiment.
• To evaluate the role of paraphoton models in resolving discrepancies observed in the PVLAS and CAST experiments.

Main Methods:

• Analysis of experimental data from searches for non-Newtonian forces.
• Theoretical modeling of particle interactions and radiative couplings.
• Comparison of theoretical predictions with experimental observations from PVLAS and CAST.

Main Results:

• Experimental constraints on exotic fifth-type forces provide stringent limits on the phigammagamma coupling.
• The derived constraints have significant implications for interpreting recent PVLAS results.
• The study clarifies the viability of paraphoton models in the context of these constraints.

Conclusions:

• The phigammagamma coupling of light scalar particles is highly constrained by fifth-force searches.
• These constraints necessitate a re-evaluation of interpretations for experiments like PVLAS.
• Paraphoton models require further refinement to reconcile with stringent experimental limits.