First measurements of vector boson scattering in W${}^{\pm }$W${}^{\pm }$ and WZ production in all-leptonic final states at $\sqrt{s}$ = 13.6 TeV

The production cross sections of W${}^{\pm }$W${}^{\pm }$ and WZ boson pairs in association with two jets in proton-proton collisions are measured at $\sqrt{s}$ = 13.6 TeV. The data sample corresponds to an integrated luminosity of 171 fb${}^{-1}$, collected with the CMS detector during 2022$-$2024. The measurements are performed in the leptonic decay modes: W${}^{\pm }$Z $\to$ ${\mathrm{\ell }}^{\pm }\nu {\mathrm{\ell }}^{\mathrm{\prime }\pm }{\mathrm{\ell }}^{\mathrm{\prime }\mp }$ and W${}^{\pm }$W${}^{\pm }$ $\to$ ${\mathrm{\ell }}^{\pm }\nu {\mathrm{\ell }}^{\mathrm{\prime }\pm }\nu$, where $\mathrm{\ell },{\mathrm{\ell }}^{\mathrm{\prime }}$ = e or $\mu$. The electroweak productions of W${}^{\pm }$W${}^{\pm }$ and WZ bosons are each observed with a significance greater than five standard deviations from the background-only hypothesis. Differential fiducial cross sections as functions of several observables are also measured.