Fig. 4: Derived \(95 \%\) confidence level upper limits on the coupling parameter \({\epsilon }^{2}\) for dark photon-baryon coupling. | Communications Physics

Fig. 4: Derived \(95 \%\) confidence level upper limits on the coupling parameter \({\epsilon }^{2}\) for dark photon-baryon coupling.

From: Searching for dark photon dark matter in LIGO O1 data

Fig. 4

The broad red band shows the actual upper limits with \(1/1800\) Hz binning. The yellow curve shows the expected upper limit for an average measured real (SNR) = 0. The dark blue curve shows the “optimal” upper limit expected when the discrete Fourier transform (DFT) binning adjusts with frequency to maintain \(\Delta f/f=1{0}^{-6}\) for the same 893-h observation time. The magenta curve shows the “optimal” upper limit expected for a 2-year, \(100 \%\)-livetime run at Advanced LIGO design sensitivity (“O4-O5"). The dashed curve shows upper limits derived from the Eöt-Wash group24,25. This is a fifth-force experiment, whose constraint does not rely on dark photon (DP) being dark matter (DM). The large spikes of red and blue curves, overlaid on top of each other, are induced by known sources of noise, such as vibrations of mirror suspension fibers.

Back to article page