The photon-energy spectrum in $B\to X_s\gamma$ to N${}^3$LO: light-fermion and large-$N_{\mathrm{c}}$ corrections

Matteo Fael, Fabian Lange, Kay Schönwald +1

We calculate the photon-energy spectrum of the inclusive radiative decay $B\to X_s\gamma$, induced by the electromagnetic dipole operator $O_7$, to next-to-next-to-next-to-leading order…