<math display="inline"><msub><mi>N</mi><mrow><mi>eff</mi></mrow></msub></math> in the Standard Model at NLO is 3.043
- Cielo, Mattia et al
- arXiv:2306.05460CERN-TH-2023-103
 | Born diagram for $e^+e^-\to \bar{\nu} \nu$ annihilations and NLO QED corrections to the $e^+e^-\to \bar{\nu} \nu$ process, including processes contributing to: 1) electron mass and wave function renormalization, 2) electromagnetic vertex correction, and 3) photon emission and absorption. |
 | The relative difference in the $e^+e^-\to \bar{\nu}\nu$ energy transfer rate between the NLO QED and Born scenarios as a function of temperature as calculated in this study. In grey, we highlight the approximate epoch at which neutrinos decouple in the early Universe. |