Measurement of cross sections for production of a Z boson in association with a flavor-inclusive or doubly b-tagged large-radius jet in proton-proton collisions at ffiffi ps = 13 TeV with the ATLAS experiment

We present measurements of cross sections for production of a leptonically decaying Z boson in association with a large-radius jet in 13 TeV proton-proton collisions at the LHC, using 36 fb−1 of data from the ATLAS detector. Integrated and differential cross sections are measured at particle level in both a flavor inclusive and a doubly b-tagged fiducial phase space. The large-radius jet mass and transverse momentum, its kinematic relationship to the Z boson, and the angular separation of b-tagged small-radius track jets within the large-radius jet are measured. This measurement constitutes an important test of perturbative quantum chromodynamics in kinematic and flavor configurations relevant to several Higgs boson and beyond-Standard-Model physics analyses. The results highlight issues with modeling of additional hadronic activity in the flavor-inclusive selection, and a distinction between flavor-number schemes in the b-tagged phase space ; ASGC (Taiwan), RAL ; BSF-NSF ; CEA-DRF ; Cantons of Bern and Geneva ; Czech Republic ; Danish Natural Science Research Council ; Department of Science and Innovation ; Direction des Sciences de la Matière, Commissariat à l’Énergie Atomique ; EU-ESF ; GenT Programmes Generalitat Valenciana, Spain ; General Secretariat for Research and Innovation ; GridKA ; INFN-CNAF ; Institut de recherche sur les lois fondamentales de l’Univers ; La Caixa Banking Foundation ; MIZŠ ; MNE ; Ministry of Education, Science, Research and Sport ; NDGF CC-IN2P3 ; Norwegian Financial Mechanism 2014-2021 ; PROMETEO ; Secretariat for Education and Research ; University Research Center SCI/013 ; Wallenberg Foundation ; Yerevan Physics Institute ; National Science Foundation ; U.S. Department of Energy ; Alexander von Humboldt-Stiftung ; Brookhaven National Laboratory ; CRC Health Group ; Karlsruhe Institute of Technology ; H2020 Marie Skłodowska-Curie Actions ; Multiple Sclerosis Scientific Research Foundation ; CERN ; Compute Canada ; Göran Gustafssons Stiftelser ; Azərbaycan Milli Elmlər ...