Measurement of VZ production cross sections in VZ to Vbbbar decay channels in pp collisions at 8 TeV

A measurement of the VZ (V=W,Z) production cross section in proton-proton collisions at $\sqrt{s} = 8$ TeV in the VZ $\rightarrow \mathrm{Vb\bar{b}}$ decay mode with, $\mathrm{Z}\to\nu\bar{\nu}$, $\mathrm{W}\to\ell\nu$ and $\mathrm{Z}\to\ell\ell$ ($\ell = e, \mu$) is presented. The results are based on data corresponding to an integrated luminosity of 18.9 fb$^{-1}$ collected with the CMS experiment at the Large Hadron Collider. The process is observed with a significance exceeding six standard deviations. The cross sections are determined to be $\sigma (pp \rightarrow \mathrm{WZ}) = 30.7 \pm 9.3(\mathrm{stat.}) \pm 7.1 (\mathrm{syst.}) \pm 4.1 (\mathrm{theo.}) \pm 1.0 (\mathrm{lumi.})\, \rm{pb}$ and $\sigma (pp \rightarrow \mathrm{ZZ}) = 6.5 \pm 1.7(\mathrm{stat.}) \pm 1.0 (\mathrm{syst.}) \pm 0.9 (\mathrm{theo.}) \pm 0.2 (\mathrm{lumi.})\, \rm{pb}$, for the Z bosons produced in the mass region $60 < M_{\mathrm{Z}} < 120$ GeV. Both values are consistent with the predictions of next-to-leading order quantum chromodynamics calculations.