First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at √&lt;em&gt;s&lt;/em&gt; = 13 TeV

Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Escalante Del Valle, A.; Frühwirth, R.; Jeitler, M.; Krammer, N.; Lechner, L.; Caminada, L.; Ebrahimi, A.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H.C.; Kotlinski, D.; Langenegger, U.; Missiroli, M.; Rohe, T.; Vetens, W.

doi:10.1016/j.physletb.2021.136565

First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at √s = 13 TeV

Sirunyan AM, Tumasyan A, Adam W, Bergauer T, Dragicevic M, Escalante Del Valle A, Frühwirth R, Jeitler M, Krammer N, Lechner L, Caminada L, Ebrahimi A, Erdmann W, Horisberger R, Ingram Q, Kaestli HC, Kotlinski D, Langenegger U, Missiroli M, Rohe T, Vetens W, et al.

Citation

Sirunyan, A. M., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., Escalante Del Valle, A., … Vetens, W. (2021). First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at √s = 13 TeV. Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, 820, 136565 (30 pp.). https://doi.org/10.1016/j.physletb.2021.136565

Persistent URL https://www.dora.lib4ri.ch/psi/islandora/object/psi:39431

The first measurement of the inclusive cross section for top quark pairs (tt‾) produced in association with two additional charm jets is presented. The analysis uses the dileptonic final states of tt‾ events produced in proton-proton collisions at a centre-of-mass energy of 13 TeV. The data correspond to an integrated luminosity of 41.5 fb^-1, recorded by the CMS experiment at the LHC. A new charm jet identification algorithm provides input to a neural network that is trained to distinguish among tt‾ events with two additional charm (tt‾cc‾), bottom (tt‾bb‾), and light-flavour or gluon (tt‾LL) jets. By means of a template fitting procedure, the inclusive tt‾cc‾, tt‾bb‾, and tt‾LL cross sections are simultaneously measured, together with their ratios to the inclusive tt‾ + two jets cross section. This provides measurements of the tt‾cc‾ and tt‾bb‾ cross sections of 10.1 ± 1.2 (stat) ± 1.4 (syst)pb and 4.54 ± 0.35 (stat) ± 0.56 (syst)pb, respectively, in the full phase space. The results are compared and found to be consistent with predictions from two different matrix element generators with next-to-leading order accuracy in quantum chromodynamics, interfaced with a parton shower simulation.

Details

Publication Type

Journal Article

Title

First measurement of the cross section for top quark pair production with additional charm jets using dileptonic final states in pp collisions at √s = 13 TeV

Author(s)

Sirunyan, A.M.

Tumasyan, A.

Adam, W.

Bergauer, T.

Dragicevic, M.

Escalante Del Valle, A.

Frühwirth, R.

Jeitler, M.

Krammer, N.

Lechner, L.

Caminada, L. (3202 High Energy Particle Physics)