Recent measurements of top-associated cross sections in low pileup conditions in pp collisions at $\sqrt{s}$ =5.02 TeV

We present the most recent measurements of top production cross sections in proton-proton collisions at a center-of-mass energy of 5.02~TeV. The dataset used was recorded in 2017 by the CMS experiment at the LHC in special runs, featuring a low-pileup environment, which offers a clean setting for precise cross-section measurements. More precisely, the two dominant top quark production processes, pair production ($\mathrm{t\bar{t}}$) and single top production in the so-called $t$ channel are measured. The measured cross section for the pair production case is $\sigma(\mathrm{t\bar{t}})= 62.3 \pm 1.5 \mathrm{(stat)} \pm 2.7 \mathrm{(syst)}$~pb, consistent with Standard Model (SM) predictions. For the single top quark production in the $t$ channel, a cross section of $\sigma(\mathrm{tq}+\mathrm{\bar{t}q})= 30.2 \pm 3.7 \mathrm{(stat)} \pm 4.3 \mathrm{(syst)}$~pb is measured. In addition, the top quark and antiquark cross sections are extracted and found to be $\sigma(\mathrm{tq})= 21.1 \pm 2.9 \mathrm{(stat)} \pm 2.8 \mathrm{(syst)}$~pb and $\sigma(\mathrm{\bar{t}q})= 8.2 \pm 2.4 \mathrm{(stat)} \pm 1.9 \mathrm{(syst)}$~pb, respectively. Finally, their ratio is also measured to be $\mathcal{R}_{t-ch}=2.58^{+1.10}_{-0.67}\mathrm{(stat)}^{+0.67}_{-0.21}\mathrm{(syst)}$. These measurements are in good agreement with the SM.