Determination of pseudo-Goldstone boson-photon coupling by the differential time delay of pulsar signals

Abstract

Pseudo-Goldstone bosons couple with photons through a P and T violating interaction of the form ${\mathcal{L}}_{\mathcal{I}}=g_{a\gamma \gamma }aF\tilde{F}$. Strong magnetic fields in rotating compact stars induce a non-zero $\vec{E}\cdot \vec{B}$ outside the stellar surface which acts as a source for the pseudo-scalar field. Pulsar signals propagating through this pseudo-scalar `hair' suffer a differential time lag between the left and the right circularly polarised modes because of the P and T violating pseudoscalar boson-photon interaction. Determination of this time lag upto a microsecond accuracy can lead to a measurment of (or rule out) pseudo-Goldstone boson-photon coupling upto $g_{a\gamma \gamma }\le 4.6\times 10^{-9}Ge{V}^{-1}$.

Comments: Plain TeX,12 pages,IP/BBSR/92-92