Define the baryon asymmetry, which sometimes is called the baryon density, as the baryons to photons ratio $\eta = n_b/n_\gamma$.
I found in Ref. 1, published in 2018, that the value of $\eta$ is of order $ 6.1 \pm 0.3 \times 10^{-10} $ by observing the cosmic microwave background experimentally by Planck satellite. However in Ref. 2, published this year, $\eta \approx 8.6 \pm 0.1 \times 10^{-11} $ as observed experimentally as well according to the particle data group (PDG).
So the value of $\eta$ is which one of these? Is it the recent one? Or the procedure of observation is different in each study?
References:
- N. E. Mavromatos, Matter-antimatter asymmetry in the universe via string-inspired CPT violation at early eras, J. Phys.: Conf. Ser. 952 012006, arXiv:1708.08350.
- S. A. Shapira, Current bounds on baryogenesis from complex Yukawa couplings of light fermions, arXiv:2106.05338.