English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Measurements of inclusive and normalized differential cross sections of theassociated production of top quark-antiquark and bottom quark-antiquark pairs,ttbb, are presented. The results are based on data from proton-protoncollisions collected by the CMS detector at a centre-of-mass energy of 13 TeV,corresponding to an integrated luminosity of 138 fb$^{-1}$. The cross sectionsare measured in the lepton+jets decay channel of the top quark pair, usingevents containing exactly one isolated electron or muon and at least five jets.Measurements are made in four fiducial phase space regions, targeting differentaspects of the ttbb process. Distributions are unfolded to the particle levelthrough maximum likelihood fits, and compared with predictions from severalevent generators. The inclusive cross section measurements of this process inthe fiducial phase space regions are the most precise to date. In most cases,the measured inclusive cross sections exceed the predictions with the chosengenerator settings. The only exception is when using a particular choice ofdynamic renormalization scale, $\mu_\mathrm{R}=\frac{1}{2} \prod_{i=\mathrm{t,\bar{t}, b, \bar{b}}} m_{\mathrm{T},i}^{1/4}$, where$m_{\mathrm{T},i}^2=m_i^2+p^2_{\mathrm{T},i}$ are the transverse masses of topand bottom quarks. The differential cross sections show varying degrees ofcompatibility with the theoretical predictions, and none of the testedgenerators with the chosen settings simultaneously describe all the measureddistributions.

Inclusive and differential cross section measurements of $\mathrm{t\bar{t}b\bar{b}}$ production in the lepton+jets channel at $\sqrt{s}$ = 13 TeV