Measurement of chi(c1) and chi(c2) production with root s=7 TeV pp collisions at ATLAS
Citation
ADD, G., ABAJYAN, T., ABBOTT, B., ABDALLAH, J., KHALEK, S.A., ABDINOV, O., ATLAS Collaboration. (2014). Measurement of chi(c1) and chi(c2) production with root s=7 TeV pp collisions at ATLAS. Journal of High Energy Physics, Issue 7, 51p. https://dx.doi.org/10.1007/JHEP07(2014)154.Abstract
The prompt and non-prompt production cross-sections for the chi(c1) and chi(c2) charmonium states are measured in pp collisions at root s = 7TeV 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.
