Measurement of associated Z + charm production in proton–proton collisions at $$\sqrt{s} = 8$$ s = 8 $$\,\text {TeV}$$ TeV

Abstract A study of the associated production of a $$\mathrm{Z} $$ Z boson and a charm quark jet ($$\mathrm{Z} + \mathrm{c} $$ Z+c ), and a comparison to production with a $$\mathrm{b} $$ b quark jet ($$\mathrm{Z} + \mathrm{b} $$ Z+b ), in $$\mathrm {p}\mathrm {p}$$ pp collisions at a centre-of-mass energy of 8$$\,\text {TeV}$$ TeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7$$\,\text {fb}^{-1}$$ fb-1 , collected with the CMS detector at the CERN LHC. The $$\mathrm{Z} $$ Z boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of $$\mathrm{c} $$ c or $$\mathrm{b} $$ b flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons with $$p_{\mathrm {T}} ^{\ell } > 20\,\text {GeV} $$ pTℓ>20GeV , $${|\eta ^{\ell }|} < 2.1$$ |ηℓ|