Discriminating the heavy jet production mechanisms in associated Z + heavy flavor events at the LHC

Abstract

Abstract We reconsider the associated Z boson and charm or beauty jet production at the LHC by paying special attention to the formation dynamics of heavy jets. Two different approaches are studied: first one, where heavy quarks are produced in the hard scattering subprocesses, implemented in the Monte-Carlo generator pegasus, and another method, where the hard scattering is calculated at NLO with MadGraph5_aMC@NLO and TMD parton shower is included (implemented in the Monte-Carlo generator Cascade3). We compare the predictions obtained in both schemes with latest experimental data for associated $$Z + b$$ Z + b production cross sections and the relative production rate $$\sigma (Z + c)/\sigma (Z + b)$$ σ ( Z + c ) / σ ( Z + b ) collected by the ATLAS and CMS Collaborations at $$\sqrt{s} = 13$$ s = 13 TeV. We introduce two kinematic observables (denoted as $$z_b$$ z b and $$p_T^\mathrm{rel}$$ p T rel ) which can be used to discriminate between the heavy jet production mechanisms. Using these variables we trace the shape of the simulated b-jet events and recommend that these observables be taken into consideration in the forthcoming experimental analyses.