pith. sign in

First results from the new PVLAS apparatus: a new limit on vacuum magnetic birefringence

2 Pith papers cite this work. Polarity classification is still indexing.

2 Pith papers citing it
abstract

Several groups are carrying out experiments to observe and measure vacuum magnetic birefringence, predicted by Quantum Electrodynamics (QED). We have started running the new PVLAS apparatus installed in Ferrara, Italy, and have measured a noise floor value for the unitary field magnetic birefringence of vacuum $\Delta n_u^{\rm (vac)}= (4\pm 20) \times 10^{-23}$ T$^{-2}$ (the error represents a 1$\sigma$ deviation). This measurement is compatible with zero and hence represents a new limit on vacuum magnetic birefringence deriving from non linear electrodynamics. This result reduces to a factor 50 the gap to be overcome to measure for the first time the value of $\Delta n_u^{\rm (vac,QED)}$ predicted by QED: $\Delta n_u^{\rm (vac,QED)}= 4\times 10^{-24}$ ~T$^{-2}$. These birefringence measurements also yield improved model-independent bounds on the coupling constant of axion-like particles to two photons, for masses greater than 1 meV, along with a factor two improvement of the fractional charge limit on millicharged particles (fermions and scalars), including neutrinos.

citation-role summary

background 1

citation-polarity summary

fields

hep-ph 2

years

2026 1 2025 1

verdicts

UNVERDICTED 2

roles

background 1

polarities

background 1

clear filters

representative citing papers

Axions as Dark Matter, Dark Energy, and Dark Radiation

hep-ph · 2025-09-21 · unverdicted · novelty 2.0

A mini-review of axion phenomenology showing how light bosons can account for dark matter, drive cosmic acceleration, or contribute to relativistic backgrounds in the early and late Universe.

citing papers explorer

Showing 1 of 1 citing paper after filters.

  • Axions as Dark Matter, Dark Energy, and Dark Radiation hep-ph · 2025-09-21 · unverdicted · none · ref 181 · internal anchor

    A mini-review of axion phenomenology showing how light bosons can account for dark matter, drive cosmic acceleration, or contribute to relativistic backgrounds in the early and late Universe.