ATLAS collaboration (2932 authors)Aguilar-Saavedra, Juan AntonioAmor Dos Santos, Susana PatriciaAnjos, NunoCantrill, RobertCarvalho, JoaoCastro, Nuno FilipeConde Muino, PatriciaDa Cunha Sargedas De Sousa, Mario JoseDo Valle Wemans, Andr\'eFiolhais, MiguelGalhardo, BrunoGomes, AgostinhoGon\c calo, RicardoJorge, PedroLopes, LourencoMachado Miguens, JoanaMaio, Am\'eliaManeira, Jos\'eMarques, CarlosOliveira, Miguel AlfonsoOnofre, Ant\'onioPalma, AlbertoPedro, RutePina, Joao AntonioPinto, BelmiroSantos, HelenaSaraiva, JoaoSilva, Jos\'eTavares Delgado, AdemarVeloso, FilipeWolters, Helmut2019-02-042019-02-042014http://dx.doi.org/10.1007/JHEP07(2014)154http://hdl.handle.net/10400.26/26574The prompt and non-prompt production cross-sections for the chi_c1 and chi_c2 charmonium states are measured in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector at the LHC using 4.5 fb^-1 of integrated luminosity. The chi_c states are reconstructed through the radiative decay chi_c -> J/psi gamma (with J/psi -> mu+mu-) where photons are reconstructed from gamma -> e+e- conversions. The production rate of the chi_c2 state relative to the chi_c1 state is measured for prompt and non-prompt chi_c as a function of J/psi transverse momentum. The prompt chi_c cross-sections are combined with existing measurements of prompt J/psi production to derive the fraction of prompt J/psi produced in feed-down from chi_c decays. The fractions of chi_c1 and chi_c2 produced in b-hadron decays are also measured.engjournal article2019-02-04